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Automated abnormality detection in lower extremity radiographs using deep learning NATURE MACHINE INTELLIGENCE Varma, M., Lu, M., Gardner, R., Dunnmon, J., Khandwala, N., Rajpurkar, P., Long, J., Beaulieu, C., Shpanskaya, K., Li Fei-Fei, Lungren, M. P., Patel, B. N. 2019; 1 (12): 578?83
View details for DOI 10.1038/s42256-019-0126-0

View details for Web of Science ID 000571267000009
Combined 5-minute double-echo in steady-state with separated echoes and 2-minute proton-density-weighted 2D FSE sequence for comprehensive whole-joint knee MRI assessment. Journal of magnetic resonance imaging : JMRI Chaudhari, A. S., Stevens, K. J., Sveinsson, B., Wood, J. P., Beaulieu, C. F., Oei, E. H., Rosenberg, J. K., Kogan, F., Alley, M. T., Gold, G. E., Hargreaves, B. A. 2018
Abstract

BACKGROUND: Clinical knee MRI protocols require upwards of 15 minutes of scan time.PURPOSE/HYPOTHESIS: To compare the imaging appearance of knee abnormalities depicted with a 5-minute 3D double-echo in steady-state (DESS) sequence with separate echo images, with that of a routine clinical knee MRI protocol. A secondary goal was to compare the imaging appearance of knee abnormalities depicted with 5-minute DESS paired with a 2-minute coronal proton-density fat-saturated (PDFS) sequence.STUDY TYPE: Prospective.SUBJECTS: Thirty-six consecutive patients (19 male) referred for a routine knee MRI.FIELD STRENGTH/SEQUENCES: DESS and PDFS at 3T.ASSESSMENT: Five musculoskeletal radiologists evaluated all images for the presence of internal knee derangement using DESS, DESS+PDFS, and the conventional imaging protocol, and their associated diagnostic confidence of the reading.STATISTICAL TESTS: Differences in positive and negative percent agreement (PPA and NPA, respectively) and 95% confidence intervals (CIs) for DESS and DESS+PDFS compared with the conventional protocol were calculated and tested using exact McNemar tests. The percentage of observations where DESS or DESS+PDFS had equivalent confidence ratings to DESS+Conv were tested with exact symmetry tests. Interreader agreement was calculated using Krippendorff's alpha.RESULTS: DESS had a PPA of 90% (88-92% CI) and NPA of 99% (99-99% CI). DESS+PDFS had increased PPA of 99% (95-99% CI) and NPA of 100% (99-100% CI) compared with DESS (both P < 0.001). DESS had equivalent diagnostic confidence to DESS+Conv in 94% of findings, whereas DESS+PDFS had equivalent diagnostic confidence in 99% of findings (both P < 0.001). All readers had moderate concordance for all three protocols (Krippendorff's alpha 47-48%).DATA CONCLUSION: Both 1) 5-minute 3D-DESS with separated echoes and 2) 5-minute 3D-DESS paired with a 2-minute coronal PDFS sequence depicted knee abnormalities similarly to a routine clinical knee MRI protocol, which may be a promising technique for abbreviated knee MRI.LEVEL OF EVIDENCE: 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.

View details for PubMedID 30582251
Deep-learning-assisted diagnosis for knee magnetic resonance imaging: Development and retrospective validation of MRNet. PLoS medicine Bien, N., Rajpurkar, P., Ball, R. L., Irvin, J., Park, A., Jones, E., Bereket, M., Patel, B. N., Yeom, K. W., Shpanskaya, K., Halabi, S., Zucker, E., Fanton, G., Amanatullah, D. F., Beaulieu, C. F., Riley, G. M., Stewart, R. J., Blankenberg, F. G., Larson, D. B., Jones, R. H., Langlotz, C. P., Ng, A. Y., Lungren, M. P. 2018; 15 (11): e1002699
Abstract

BACKGROUND: Magnetic resonance imaging (MRI) of the knee is the preferred method for diagnosing knee injuries. However, interpretation of knee MRI is time-intensive and subject to diagnostic error and variability. An automated system for interpreting knee MRI could prioritize high-risk patients and assist clinicians in making diagnoses. Deep learning methods, in being able to automatically learn layers of features, are well suited for modeling the complex relationships between medical images and their interpretations. In this study we developed a deep learning model for detecting general abnormalities and specific diagnoses (anterior cruciate ligament [ACL] tears and meniscal tears) on knee MRI exams. We then measured the effect of providing the model's predictions to clinical experts during interpretation.METHODS AND FINDINGS: Our dataset consisted of 1,370 knee MRI exams performed at Stanford University Medical Center between January 1, 2001, and December 31, 2012 (mean age 38.0 years; 569 [41.5%] female patients). The majority vote of 3 musculoskeletal radiologists established reference standard labels on an internal validation set of 120 exams. We developed MRNet, a convolutional neural network for classifying MRI series and combined predictions from 3 series per exam using logistic regression. In detecting abnormalities, ACL tears, and meniscal tears, this model achieved area under the receiver operating characteristic curve (AUC) values of 0.937 (95% CI 0.895, 0.980), 0.965 (95% CI 0.938, 0.993), and 0.847 (95% CI 0.780, 0.914), respectively, on the internal validation set. We also obtained a public dataset of 917 exams with sagittal T1-weighted series and labels for ACL injury from Clinical Hospital Centre Rijeka, Croatia. On the external validation set of 183 exams, the MRNet trained on Stanford sagittal T2-weighted series achieved an AUC of 0.824 (95% CI 0.757, 0.892) in the detection of ACL injuries with no additional training, while an MRNet trained on the rest of the external data achieved an AUC of 0.911 (95% CI 0.864, 0.958). We additionally measured the specificity, sensitivity, and accuracy of 9 clinical experts (7 board-certified general radiologists and 2 orthopedic surgeons) on the internal validation set both with and without model assistance. Using a 2-sided Pearson's chi-squared test with adjustment for multiple comparisons, we found no significant differences between the performance of the model and that of unassisted general radiologists in detecting abnormalities. General radiologists achieved significantly higher sensitivity in detecting ACL tears (p-value = 0.002; q-value = 0.019) and significantly higher specificity in detecting meniscal tears (p-value = 0.003; q-value = 0.019). Using a 1-tailed t test on the change in performance metrics, we found that providing model predictions significantly increased clinical experts' specificity in identifying ACL tears (p-value < 0.001; q-value = 0.006). The primary limitations of our study include lack of surgical ground truth and the small size of the panel of clinical experts.CONCLUSIONS: Our deep learning model can rapidly generate accurate clinical pathology classifications of knee MRI exams from both internal and external datasets. Moreover, our results support the assertion that deep learning models can improve the performance of clinical experts during medical imaging interpretation. Further research is needed to validate the model prospectively and to determine its utility in the clinical setting.

View details for PubMedID 30481176
Is it painful to be different? Sciatic nerve anatomical variants on MRI and their relationship to piriformis syndrome EUROPEAN RADIOLOGY Bartret, A. L., Beaulieu, C. F., Lutz, A. M. 2018; 28 (11): 4681?86
View details for DOI 10.1007/s00330-018-5447-6

View details for Web of Science ID 000446542300023
Deep-learning-assisted diagnosis for knee magnetic resonance imaging: Development and retrospective validation of MRNet PLOS MEDICINE Bien, N., Rajpurkar, P., Ball, R. L., Irvin, J., Park, A., Jones, E., Bereket, M., Patel, B. N., Yeom, K. W., Shpanskaya, K., Halabi, S., Zucker, E., Fanton, G., Amanatullah, D. F., Beaulieu, C. F., Riley, G. M., Stewart, R. J., Blankenberg, F. G., Larson, D. B., Jones, R. H., Langlotz, C. P., Ng, A. Y., Lungren, M. P. 2018; 15 (11)
View details for DOI 10.1371/journal.pmed.1002699

View details for Web of Science ID 000451827800015
Relevance feedback for enhancing content based image retrieval and automatic prediction of semantic image features: Application to bone tumor radiographs JOURNAL OF BIOMEDICAL INFORMATICS Banerjee, I., Kurtz, C., Devorah, A., Do, B., Rubin, D. L., Beaulieu, C. F. 2018; 84: 123?35
View details for DOI 10.1016/j.jbi.2018.07.002

View details for Web of Science ID 000445054800012
Accelerated three-dimensional multispectral MRI with robust principal component analysis for separation of on- and off-resonance signals MAGNETIC RESONANCE IN MEDICINE Levine, E., Stevens, K., Beaulieu, C., Hargreaves, B. 2018; 79 (3): 1495?1505
Abstract

To enable highly accelerated distortion-free MRI near metal by separating on- and off-resonance to exploit the redundancy of slice-phase encoding for the dominant on-resonance component.Multispectral MRI techniques resolve off-resonance distortions by a combination of limited excitation bins and additional encoding. Inspired by robust principal component analysis, a novel compact representation of multispectral images as a sum of rank-one and sparse matrices corresponding to on- and off-resonance respectively is described. This representation is used in a calibration-free and model-free reconstruction for data with an undersampling pattern that varies between bins. Retrospective undersampling was used to compare the proposed reconstruction and bin-by-bin compressed sensing. Hip images were acquired in eight patients with standard and prospectively undersampled three-dimensional multispectral imaging, and image quality was evaluated by two radiologists on a 5-point scale.Experiments with retrospective undersampling showed that the enhanced sparsity afforded by the separation greatly reduces reconstruction errors and artifacts. Images from prospectively undersampled multispectral imaging offered 2.6-3.4-fold (18-24-fold overall) acceleration compared to standard multispectral imaging with parallel imaging and partial-Fourier acceleration with equivalence in all qualitative assessments within a tolerance of one point (P?
View details for PubMedID 28686800

View details for PubMedCentralID PMC5756705
Relevance Feedback for Enhancing Content Based Image Retrieval and Automatic Prediction of Semantic Image Features: Application to Bone Tumor Radiographs. Journal of biomedical informatics Banerjee, I., Kurtz, C., Edward Devorah, A., Do, B., Rubin, D. L., Beaulieu, C. F. 2018
Abstract

The majority of current medical CBIR systems perform retrieval based only on "imaging signatures" generated by extracting pixel-level quantitative features, and only rarely has a feedback mechanism been incorporated to improve retrieval performance. In addition, current medical CBIR approaches do not routinely incorporate semantic terms that model the user's high-level expectations, and this can limit CBIR performance.We propose a retrieval framework that exploits a hybrid feature space (HFS) that is built by integrating low-level image features and high-level semantic terms, through rounds of relevance feedback (RF) and performs similarity-based retrieval to support semi-automatic image interpretation. The novelty of the proposed system is that it can impute the semantic features of the query image by reformulating the query vector representation in the HFS via user feedback. We implemented our framework as a prototype that performs the retrieval over a database of 811 radiographic images that contains 69 unique types of bone tumors.We evaluated the system performance by conducting independent reading sessions with two subspecialist musculoskeletal radiologists. For the test set, the proposed retrieval system at fourth RF iteration of the sessions conducted with both the radiologists achieved mean average precision (MAP) value ? 0.90 where the initial MAP with baseline CBIR was 0.20. In addition, we also achieved high prediction accuracy (>0.8) for the majority of the semantic features automatically predicted by the system.Our proposed framework addresses some limitations of existing CBIR systems by incorporating user feedback and simultaneously predicting the semantic features of the query image. This obviates the need for the user to provide those terms and makes CBIR search more efficient for inexperience users/trainees. Encouraging results achieved in the current study highlight possible new directions in radiological image interpretation employing semantic CBIR combined with relevance feedback of visual similarity.

View details for PubMedID 29981490
Is it painful to be different? Sciatic nerve anatomical variants on MRI and their relationship to piriformis syndrome. European radiology Bartret, A. L., Beaulieu, C. F., Lutz, A. M. 2018
Abstract

To investigate the purported relationship between sciatic nerve variant anatomy and piriformis syndrome.Over 49 months, 1039 consecutive noncontrast adult hip MRIs were completed for various clinical indications. Repeat and technically insufficient studies were excluded. Radiologists categorized sciatic nerve anatomy into Beaton and Anson anatomical types. Chart review using our institution's cohort search and navigation tool determined the prevalence of the explicit clinical diagnosis of piriformis syndrome (primary endpoint) and sciatica and buttock pain (secondary endpoints). A Z-test compared the prevalence of each diagnosis in the variant anatomy and normal groups.Seven hundred eighty-three studies were included, with sciatic nerve variants present in 150 hips (19.2%). None of the diagnoses had a statistically significant difference in prevalence between the variant and normal hip groups. Specifically, piriformis syndrome was present in 11.3% of variant hips compared with 9.0% of normal hips (p = 0.39).There were no significant differences in the prevalence of piriformis syndrome, buttock pain, or sciatica between normal and variant sciatic nerve anatomy. This large-scale correlative radiologic study into the relationship between sciatic nerve variants and piriformis syndrome calls into question this purported relationship.? Large retrospective study relating variant sciatic nerve anatomy, present in 19.2% of hip MRIs, and piriformis syndrome ? While sciatic nerve variant anatomy has previously been implicated in piriformis syndrome in small studies, no relationship was identified between sciatic nerve variants and piriformis syndrome.

View details for PubMedID 29713768
Musculotendinous Injuries: Sonographic-guided Interventions SEMINARS IN MUSCULOSKELETAL RADIOLOGY Wood, J. P., Beaulieu, C. F. 2017; 21 (4): 470?83
View details for PubMedID 28772323
Detection and prevalence of variant sciatic nerve anatomy in relation to the piriformis muscle on MRI SKELETAL RADIOLOGY Varenika, V., Lutz, A. M., Beaulieu, C. F., Bucknor, M. D. 2017; 46 (6): 751-757
Abstract

To determine whether known variant anatomical relationships between the sciatic nerve and piriformis muscle can be identified on routine MRI studies of the hip and to establish their imaging prevalence.Hip MRI studies acquired over a period of 4�years at two medical centers underwent retrospective interpretation. Anatomical relationship between the sciatic nerve and the piriformis muscle was categorized according to the Beaton and Anson classification system. The presence of a split sciatic nerve at the level of the ischial tuberosity was also recorded.A total of 755 consecutive scans were reviewed. Conventional anatomy (type I), in which an undivided sciatic nerve passes below the piriformis muscle, was identified in 87% of cases. The remaining 13% of cases demonstrated a type II pattern in which one division of the sciatic nerve passes through the piriformis whereas the second passes below. Only two other instances of variant anatomy were identified (both type III). Most variant cases were associated with a split sciatic nerve at the level of the ischial tuberosity (73 out of 111, 65.8%). By contrast, only 6% of cases demonstrated a split sciatic nerve at this level in the context of otherwise conventional anatomy.Anatomical variations of the sciatic nerve course in relation to the piriformis muscle are frequently identified on routine MRI of the hips, occurring in 12-20% of scans reviewed. Almost all variants identified were type II. The ability to recognize variant sciatic nerve courses on MRI may prove useful in optimal treatment planning.

View details for DOI 10.1007/s00256-017-2597-6

View details for Web of Science ID 000399447500004

View details for PubMedID 28280851
Adaptive local window for level set segmentation of CT and MRI liver lesions. Medical image analysis Hoogi, A., Beaulieu, C. F., Cunha, G. M., Heba, E., Sirlin, C. B., Napel, S., Rubin, D. L. 2017; 37: 46-55
Abstract

We propose a novel method, the adaptive local window, for improving level set segmentation technique. The window is estimated separately for each contour point, over iterations of the segmentation process, and for each individual object. Our method considers the object scale, the spatial texture, and the changes of the energy functional over iterations. Global and local statistics are considered by calculating several gray level co-occurrence matrices. We demonstrate the capabilities of the method in the domain of medical imaging for segmenting 233 images with liver lesions. To illustrate the strength of our method, those lesions were screened by either Computed Tomography or Magnetic Resonance Imaging. Moreover, we analyzed images using three different energy models. We compared our method to a global level set segmentation, to a local framework that uses predefined fixed-size square windows and to a local region-scalable fitting model. The results indicate that our proposed method outperforms the other methods in terms of agreement with the manual marking and dependence on contour initialization or the energy model used. In case of complex lesions, such as low contrast lesions, heterogeneous lesions, or lesions with a noisy background, our method shows significantly better segmentation with an improvement of 0.25?�?0.13 in Dice similarity coefficient, compared with state of the art fixed-size local windows (Wilcoxon, p
View details for DOI 10.1016/j.media.2017.01.002

View details for PubMedID 28157660

View details for PubMedCentralID PMC5393306
The incidental bone lesion on computed tomography: management tips for abdominal radiologists. Abdominal radiology Nguyen, M., Beaulieu, C., Weinstein, S., Shin, L. K. 2017
Abstract

Incidental bone lesions are commonly seen on abdominal and pelvic computed tomography (CT) examinations. These incidental bone lesions can be diagnostically challenging to the abdominal radiologist who may not be familiar with their appearance or their appropriate management. The characterization of such bone lesions as non-aggressive or aggressive based on their CT appearance involves similar principles to their morphologic evaluation on radiographs. Knowledge of the age of the patient and the presence of symptoms, mainly bone pain, can improve analysis. Examples of bone lesions that may be encountered include solitary or multifocal bone lesions, osteochondromatous and chondroid tumors, Paget's disease, avascular necrosis/bone infarctions, iatrogenic lesions, and periarticular lesions. This pictorial essay aims to provide a framework for the analysis of incidental bone lesions on CT and when further imaging and clinical work-up should be recommended.

View details for DOI 10.1007/s00261-016-1040-0

View details for PubMedID 28132074
Bone Tumor Diagnosis Using a Na�ve Bayesian Model of Demographic and Radiographic Features. Journal of digital imaging Do, B. H., Langlotz, C., Beaulieu, C. F. 2017
Abstract

Because many bone tumors have a variety of appearances and are uncommon, few radiologists develop sufficient expertise to guide optimal management. Bayesian inference can guide decision-making by computing probabilities of multiple diagnoses to generate a differential. We built and validated a na�ve Bayes machine (NBM) that processes 18 demographic and radiographic features. We reviewed over 1664 analog radiographic cases of bone tumors and selected 811 cases (66 diagnoses) for annotation using a quantitative imaging platform. Leave-one-out cross validation was performed. Primary accuracy was defined as the correct pathological diagnosis as the top machine prediction. Differential accuracy was defined as whether the correct pathological diagnosis was within the top three predictions. For the 29 most common diagnoses (710 cases), primary accuracy was 44%, and differential accuracy was 60%. For the top 10 most common diagnoses (478 cases), primary accuracy was 62%, and differential accuracy was 80%. The machine returned relevant diagnoses for the majority of unknown test cases and may be a feasible alternative to machine learning approaches such as deep neural networks or support vector machines that typically require larger training data (our model required a minimum of five samples per diagnosis) and are "black boxes" (our model can provide details of probability calculations to identify features that most significantly contribute to truth diagnoses). Finally, our Bayes model was designed to scale and "learn" from external data, enabling incorporation of outside knowledge such as Dahlin's Bone Tumors, a reference of anatomic and demographic statistics of more than 10,000 tumors.

View details for PubMedID 28752323

View details for PubMedCentralID PMC5603428
Computerized Prediction of Radiological Observations Based on Quantitative Feature Analysis: Initial Experience in Liver Lesions. Journal of digital imaging Banerjee, I., Beaulieu, C. F., Rubin, D. L. 2017; 30 (4): 506?18
Abstract

We propose a computerized framework that, given a region of interest (ROI) circumscribing a lesion, not only predicts radiological observations related to the lesion characteristics with 83.2% average prediction accuracy but also derives explicit association between low-level imaging features and high-level semantic terms by exploiting their statistical correlation. Such direct association between semantic concepts and low-level imaging features can be leveraged to build a powerful annotation system for radiological images that not only allows the computer to infer the semantics from diverse medical images and run automatic reasoning for making diagnostic decision but also provides "human-interpretable explanation" of the system output to facilitate better end user understanding of computer-based diagnostic decisions. The core component of our framework is a radiological observation detection algorithm that maximizes the low-level imaging feature relevancy for each high-level semantic term. On a liver lesion CT dataset, we have implemented our framework by incorporating a large set of state-of-the-art low-level imaging features. Additionally, we included a novel feature that quantifies lesion(s) present within the liver that have a similar appearance as the primary lesion identified by the radiologist. Our framework achieved a high prediction accuracy (83.2%), and the derived association between semantic concepts and imaging features closely correlates with human expectation. The framework has been only tested on liver lesion CT images, but it is capable of being applied to other imaging domains.

View details for PubMedID 28639186
Computerized Prediction of Radiological Observations Based on Quantitative Feature Analysis: Initial Experience in Liver Lesions Journal of Digital Imaging Banerjee, I. 2017: 506?18
Abstract

We propose a computerized framework that, given a region of interest (ROI) circumscribing a lesion, not only predicts radiological observations related to the lesion characteristics with 83.2% average prediction accuracy but also derives explicit association between low-level imaging features and high-level semantic terms by exploiting their statistical correlation. Such direct association between semantic concepts and low-level imaging features can be leveraged to build a powerful annotation system for radiological images that not only allows the computer to infer the semantics from diverse medical images and run automatic reasoning for making diagnostic decision but also provides "human-interpretable explanation" of the system output to facilitate better end user understanding of computer-based diagnostic decisions. The core component of our framework is a radiological observation detection algorithm that maximizes the low-level imaging feature relevancy for each high-level semantic term. On a liver lesion CT dataset, we have implemented our framework by incorporating a large set of state-of-the-art low-level imaging features. Additionally, we included a novel feature that quantifies lesion(s) present within the liver that have a similar appearance as the primary lesion identified by the radiologist. Our framework achieved a high prediction accuracy (83.2%), and the derived association between semantic concepts and imaging features closely correlates with human expectation. The framework has been only tested on liver lesion CT images, but it is capable of being applied to other imaging domains.

View details for DOI 10.1007/s10278-017-9987-0

View details for PubMedCentralID PMC5537098
Improved Patch-Based Automated Liver Lesion Classification by Separate Analysis of the Interior and Boundary Regions IEEE JOURNAL OF BIOMEDICAL AND HEALTH INFORMATICS Diamant, I., Hoogi, A., Beaulieu, C. F., Safdari, M., Klang, E., Amitai, M., Greenspan, H., Rubin, D. L. 2016; 20 (6): 1585-1594
Abstract

The bag-of-visual-words (BoVW) method with construction of a single dictionary of visual words has been used previously for a variety of classification tasks in medical imaging, including the diagnosis of liver lesions. In this paper, we describe a novel method for automated diagnosis of liver lesions in portal-phase computed tomography (CT) images that improves over single-dictionary BoVW methods by using an image patch representation of the interior and boundary regions of the lesions. Our approach captures characteristics of the lesion margin and of the lesion interior by creating two separate dictionaries for the margin and the interior regions of lesions ("dual dictionaries" of visual words). Based on these dictionaries, visual word histograms are generated for each region of interest within the lesion and its margin. For validation of our approach, we used two datasets from two different institutions, containing CT images of 194 liver lesions (61 cysts, 80 metastasis, and 53 hemangiomas). The final diagnosis of each lesion was established by radiologists. The classification accuracy for the images from the two institutions was 99% and 88%, respectively, and 93% for a combined dataset. Our new BoVW approach that uses dual dictionaries shows promising results. We believe the benefits of our approach may generalize to other application domains within radiology.

View details for DOI 10.1109/JBHI.2015.2478255

View details for Web of Science ID 000389846700014

View details for PubMedID 26372661

View details for PubMedCentralID PMC5164871
Chondral Rib Fractures in Professional American Football: Two Cases and Current Practice Patterns Among NFL Team Physicians. Orthopaedic journal of sports medicine McAdams, T. R., Deimel, J. F., Ferguson, J., Beamer, B. S., Beaulieu, C. F. 2016; 4 (2): 2325967115627623-?
Abstract

Although a recognized and discussed injury, chondral rib fractures in professional American football have not been previously reported in the literature. There currently exists no consensus on how to identify and treat these injuries or the expected return to play for the athlete.To present 2 cases of chondral rib injuries in the National Football League (NFL) and discuss the current practice patterns for management of these injuries among the NFL team physicians.Case series; Level of evidence, 4.Two cases of NFL players with chondral rib injuries are presented. A survey regarding work-up and treatment of these injuries was completed by team physicians at the 2014 NFL Combine. Our experience in identifying and treating these injuries is presented in conjunction with a survey of NFL team physicians' experiences.Two cases of rib chondral injuries were diagnosed by computed tomography (CT) and treated with rest and protective splinting. Return to play was 2 to 4 weeks. NFL Combine survey results show that NFL team physicians see a mean of 4 costal cartilage injuries per 5-year period, or approximately 1 case per year per team. Seventy percent of team physicians use CT scanning and 43% use magnetic resonance imaging for diagnosis of these injuries. An anesthetic block is used acutely in 57% and only electively in subsequent games by 39%.A high index of suspicion is necessary to diagnose chondral rib injuries in American football. CT scan is most commonly used to confirm diagnosis. Return to play can take up to 2 to 4 weeks with a protective device, although anesthetic blocks can be used to potentially expedite return.Chondral rib injuries are common among NFL football players, while there is no literature to support proper diagnosis and treatment of these injuries or expected duration of recovery. These injuries are likely common in other contact sports and levels of competition as well. Our series combined with NFL team physician survey results can aid team physicians in identifying these injuries, obtaining useful imaging, and counseling players and coaches and the expected time of recovery.

View details for DOI 10.1177/2325967115627623

View details for PubMedID 26925425
Piriformis Syndrome With Variant Sciatic Nerve Anatomy:�A�Case�Report. PM & R : the journal of injury, function, and rehabilitation Kraus, E., Tenforde, A. S., Beaulieu, C. F., Ratliff, J., Fredericson, M. 2016; 8 (2): 176-179
Abstract

A 68-year-old male long distance runner presented with low back and left buttock pain, which eventually progressed to severe and debilitating pain, intermittently radiating to the posterior thigh and foot. A comprehensive workup ruled out possible spine or hip causes of his symptoms. A pelvic magnetic resonance imaging neurogram with complex oblique planes through the piriformis demonstrated variant anatomy of the left sciatic nerve consistent with the clinical diagnosis of piriformis syndrome. The patient ultimately underwent neurolysis with release of the sciatic nerve and partial resection of the piriformis muscle. After surgery the patient reported significant pain reduction and resumed running 3 months later. Piriformis syndrome is uncommon but should be considered in the differential diagnosis for buttock pain. Advanced imaging was essential to guide management.

View details for DOI 10.1016/j.pmrj.2015.09.005

View details for PubMedID 26377629
Conventional versus virtual radiographs of the injured pelvis and acetabulum SKELETAL RADIOLOGY Bishop, J. A., Rao, A. J., Pouliot, M. A., Beaulieu, C., Bellino, M. 2015; 44 (9): 1303-1308
Abstract

Evaluation of the fractured pelvis or acetabulum requires both standard radiographic evaluation as well as computed tomography (CT) imaging. The standard anterior-posterior (AP), Judet, and inlet and outlet views can now be simulated using data acquired during CT, decreasing patient discomfort, radiation exposure, and cost to the healthcare system. The purpose of this study is to compare the image quality of conventional radiographic views of the traumatized pelvis to virtual radiographs created from pelvic CT scans.Five patients with acetabular fractures and ten patients with pelvic ring injuries were identified using the orthopedic trauma database at our institution. These fractures were evaluated with both conventional radiographs as well as virtual radiographs generated from a CT scan. A web-based survey was created to query overall image quality and visibility of relevant anatomic structures. This survey was then administered to members of the Orthopaedic Trauma Association (OTA).Ninety-seven surgeons completed the acetabular fracture survey and 87 completed the pelvic fracture survey. Overall image quality was judged to be statistically superior for the virtual as compared to conventional images for acetabular fractures (3.15 vs. 2.98, p?=?0.02), as well as pelvic ring injuries (2.21 vs. 1.45, p?=?0.0001). Visibility ratings for each anatomic landmark were statistically superior with virtual images as well.Virtual radiographs of pelvic and acetabular fractures offer superior image quality, improved comfort, decreased radiation exposure, and a more cost-effective alternative to conventional radiographs.

View details for DOI 10.1007/s00256-015-2171-z

View details for Web of Science ID 000358329600008
Content-based image retrieval in radiology: analysis of variability in human perception of similarity. Journal of medical imaging (Bellingham, Wash.) Faruque, J., Beaulieu, C. F., Rosenberg, J., Rubin, D. L., Yao, D., Napel, S. 2015; 2 (2): 025501-?
Abstract

We aim to develop a better understanding of perception of similarity in focal computed tomography (CT) liver images to determine the feasibility of techniques for developing reference sets for training and validating content-based image retrieval systems. In an observer study, four radiologists and six nonradiologists assessed overall similarity and similarity in 5 image features in 136 pairs of focal CT liver lesions. We computed intra- and inter-reader agreements in these similarity ratings and viewed the distributions of the ratings. The readers' ratings of overall similarity and similarity in each feature primarily appeared to be bimodally distributed. Median Kappa scores for intra-reader agreement ranged from 0.57 to 0.86 in the five features and from 0.72 to 0.82 for overall similarity. Median Kappa scores for inter-reader agreement ranged from 0.24 to 0.58 in the five features and were 0.39 for overall similarity. There was no significant difference in agreement for radiologists and nonradiologists. Our results show that developing perceptual similarity reference standards is a complex task. Moderate to high inter-reader variability precludes ease of dividing up the workload of rating perceptual similarity among many readers, while low intra-reader variability may make it possible to acquire large volumes of data by asking readers to view image pairs over many sessions.

View details for DOI 10.1117/1.JMI.2.2.025501

View details for PubMedID 26158112

View details for PubMedCentralID PMC4478987
Classification of Hypervascular Liver Lesions Based on Hepatic Artery and Portal Vein Blood Supply Coefficients Calculated from Triphasic CT Scans JOURNAL OF DIGITAL IMAGING Boas, F. E., Kamaya, A., Do, B., Desser, T. S., Beaulieu, C. F., Vasanawala, S. S., Hwang, G. L., Sze, D. Y. 2015; 28 (2): 213-223
Abstract

Perfusion CT of the liver typically involves scanning the liver at least 20 times, resulting in a large radiation dose. We developed and validated a simplified model of tumor blood supply that can be applied to standard triphasic scans and evaluated whether this can be used to distinguish benign and malignant liver lesions. Triphasic CTs of 46 malignant and 32 benign liver lesions were analyzed. For each phase, regions of interest were drawn in the arterially enhancing portion of each lesion, as well as the background liver, aorta, and portal vein. Hepatic artery and portal vein blood supply coefficients for each lesion were then calculated by expressing the enhancement curve of the lesion as a linear combination of the enhancement curves of the aorta and portal vein. Hepatocellular carcinoma (HCC) and hypervascular metastases, on average, both had increased hepatic artery coefficients compared to the background liver. Compared to HCC, benign lesions, on average, had either a greater hepatic artery coefficient (hemangioma) or a greater portal vein coefficient (focal nodular hyperplasia or transient hepatic attenuation difference). Hypervascularity with washout is a key diagnostic criterion for HCC, but it had a sensitivity of 72�% and specificity of 81�% for diagnosing malignancy in our diverse set of liver lesions. The sensitivity for malignancy was increased to 89�% by including enhancing lesions that were hypodense on all phases. The specificity for malignancy was increased to 97�% (p?=?0.039) by also examining hepatic artery and portal vein blood supply coefficients, while maintaining a sensitivity of 76�%.

View details for DOI 10.1007/s10278-014-9725-9

View details for Web of Science ID 000351242500012

View details for PubMedID 25183580
Conventional versus virtual radiographs of the injured pelvis and acetabulum. Skeletal radiology Bishop, J. A., Rao, A. J., Pouliot, M. A., Beaulieu, C., Bellino, M. 2015; 44 (9): 1303?8
Abstract

Evaluation of the fractured pelvis or acetabulum requires both standard radiographic evaluation as well as computed tomography (CT) imaging. The standard anterior-posterior (AP), Judet, and inlet and outlet views can now be simulated using data acquired during CT, decreasing patient discomfort, radiation exposure, and cost to the healthcare system. The purpose of this study is to compare the image quality of conventional radiographic views of the traumatized pelvis to virtual radiographs created from pelvic CT scans.Five patients with acetabular fractures and ten patients with pelvic ring injuries were identified using the orthopedic trauma database at our institution. These fractures were evaluated with both conventional radiographs as well as virtual radiographs generated from a CT scan. A web-based survey was created to query overall image quality and visibility of relevant anatomic structures. This survey was then administered to members of the Orthopaedic Trauma Association (OTA).Ninety-seven surgeons completed the acetabular fracture survey and 87 completed the pelvic fracture survey. Overall image quality was judged to be statistically superior for the virtual as compared to conventional images for acetabular fractures (3.15 vs. 2.98, p?=?0.02), as well as pelvic ring injuries (2.21 vs. 1.45, p?=?0.0001). Visibility ratings for each anatomic landmark were statistically superior with virtual images as well.Virtual radiographs of pelvic and acetabular fractures offer superior image quality, improved comfort, decreased radiation exposure, and a more cost-effective alternative to conventional radiographs.

View details for PubMedID 26009268
Ultrasound-guided musculoskeletal interventions in American football: 18 years of experience. AJR. American journal of roentgenology Dave, R. B., Stevens, K. J., Shivaram, G. M., McAdams, T. R., Dillingham, M. F., Beaulieu, C. F. 2014; 203 (6): W674-83
Abstract

Myotendinous strains, contusions, and hematomas are common injuries in American football. Along with ligament sprains and inflammatory disorders, musculoskeletal injuries often result in lost participation time. This article summarizes 18 years of experience with 128 ultrasound-guided drainages and injections in 69 football players with 88 injuries.When performed by an operator with sufficient expertise in diagnostic and procedural skills, ultrasound-guided musculoskeletal interventions are minimally invasive, are safe, and can play an integral role in injury management.

View details for DOI 10.2214/AJR.14.12678

View details for PubMedID 25415734
On combining image-based and ontological semantic dissimilarities for medical image retrieval applications. Medical image analysis Kurtz, C., Depeursinge, A., Napel, S., Beaulieu, C. F., Rubin, D. L. 2014; 18 (7): 1082-1100
Abstract

Computer-assisted image retrieval applications can assist radiologists by identifying similar images in archives as a means to providing decision support. In the classical case, images are described using low-level features extracted from their contents, and an appropriate distance is used to find the best matches in the feature space. However, using low-level image features to fully capture the visual appearance of diseases is challenging and the semantic gap between these features and the high-level visual concepts in radiology may impair the system performance. To deal with this issue, the use of semantic terms to provide high-level descriptions of radiological image contents has recently been advocated. Nevertheless, most of the existing semantic image retrieval strategies are limited by two factors: they require manual annotation of the images using semantic terms and they ignore the intrinsic visual and semantic relationships between these annotations during the comparison of the images. Based on these considerations, we propose an image retrieval framework based on semantic features that relies on two main strategies: (1) automatic "soft" prediction of ontological terms that describe the image contents from multi-scale Riesz wavelets and (2) retrieval of similar images by evaluating the similarity between their annotations using a new term dissimilarity measure, which takes into account both image-based and ontological term relations. The combination of these strategies provides a means of accurately retrieving similar images in databases based on image annotations and can be considered as a potential solution to the semantic gap problem. We validated this approach in the context of the retrieval of liver lesions from computed tomographic (CT) images and annotated with semantic terms of the RadLex ontology. The relevance of the retrieval results was assessed using two protocols: evaluation relative to a dissimilarity reference standard defined for pairs of images on a 25-images dataset, and evaluation relative to the diagnoses of the retrieved images on a 72-images dataset. A normalized discounted cumulative gain (NDCG) score of more than 0.92 was obtained with the first protocol, while AUC scores of more than 0.77 were obtained with the second protocol. This automatical approach could provide real-time decision support to radiologists by showing them similar images with associated diagnoses and, where available, responses to therapies.

View details for DOI 10.1016/j.media.2014.06.009

View details for PubMedID 25036769

View details for PubMedCentralID PMC4173098
Predicting Visual Semantic Descriptive Terms From Radiological Image Data: Preliminary Results With Liver Lesions in CT. IEEE transactions on medical imaging Depeursinge, A., Kurtz, C., Beaulieu, C., Napel, S., Rubin, D. 2014; 33 (8): 1669-1676
Abstract

We describe a framework to model visual semantics of liver lesions in CT images in order to predict the visual semantic terms (VST) reported by radiologists in describing these lesions. Computational models of VST are learned from image data using linear combinations of high-order steerable Riesz wavelets and support vector machines (SVM). In a first step, these models are used to predict the presence of each semantic term that describes liver lesions. In a second step, the distances between all VST models are calculated to establish a nonhierarchical computationally-derived ontology of VST containing inter-term synonymy and complementarity. A preliminary evaluation of the proposed framework was carried out using 74 liver lesions annotated with a set of 18 VSTs from the RadLex ontology. A leave-one-patient-out cross-validation resulted in an average area under the ROC curve of 0.853 for predicting the presence of each VST. The proposed framework is expected to foster human-computer synergies for the interpretation of radiological images while using rotation-covariant computational models of VSTs to 1) quantify their local likelihood and 2) explicitly link them with pixel-based image content in the context of a given imaging domain.

View details for DOI 10.1109/TMI.2014.2321347

View details for PubMedID 24808406

View details for PubMedCentralID PMC4129229
A hierarchical knowledge-based approach for retrieving similar medical images described with semantic annotations JOURNAL OF BIOMEDICAL INFORMATICS Kurtz, C., Beaulieu, C. F., Napel, S., Rubin, D. L. 2014; 49: 227-244
Abstract

Computer-assisted image retrieval applications could assist radiologist interpretations by identifying similar images in large archives as a means to providing decision support. However, the semantic gap between low-level image features and their high level semantics may impair the system performances. Indeed, it can be challenging to comprehensively characterize the images using low-level imaging features to fully capture the visual appearance of diseases on images, and recently the use of semantic terms has been advocated to provide semantic descriptions of the visual contents of images. However, most of the existing image retrieval strategies do not consider the intrinsic properties of these terms during the comparison of the images beyond treating them as simple binary (presence/absence) features. We propose a new framework that includes semantic features in images and that enables retrieval of similar images in large databases based on their semantic relations. It is based on two main steps: (1) annotation of the images with semantic terms extracted from an ontology, and (2) evaluation of the similarity of image pairs by computing the similarity between the terms using the Hierarchical Semantic-Based Distance (HSBD) coupled to an ontological measure. The combination of these two steps provides a means of capturing the semantic correlations among the terms used to characterize the images that can be considered as a potential solution to deal with the semantic gap problem. We validate this approach in the context of the retrieval and the classification of 2D regions of interest (ROIs) extracted from computed tomographic (CT) images of the liver. Under this framework, retrieval accuracy of more than 0.96 was obtained on a 30-images dataset using the Normalized Discounted Cumulative Gain (NDCG) index that is a standard technique used to measure the effectiveness of information retrieval algorithms when a separate reference standard is available. Classification results of more than 95% were obtained on a 77-images dataset. For comparison purpose, the use of the Earth Mover's Distance (EMD), which is an alternative distance metric that considers all the existing relations among the terms, led to results retrieval accuracy of 0.95 and classification results of 93% with a higher computational cost. The results provided by the presented framework are competitive with the state-of-the-art and emphasize the usefulness of the proposed methodology for radiology image retrieval and classification.

View details for DOI 10.1016/j.jbi.2014.02.018

View details for Web of Science ID 000337772200023

View details for PubMedCentralID PMC4058405
MR imaging of the brachial plexus. Neuroimaging clinics of North America Lutz, A. M., Gold, G., Beaulieu, C. 2014; 24 (1): 91-108
Abstract

Continuous improvements in magnetic resonance scanner, coil, and pulse sequence technology have resulted in the ability to perform routine, high-quality imaging of the brachial plexus. With knowledge of the anatomy of the plexus, and a familiarity with common pathologic conditions affecting this area, radiologists can provide valuable imaging evaluation of patients with brachial plexus pathologies.

View details for DOI 10.1016/j.nic.2013.03.024

View details for PubMedID 24210315
A picture is worth a thousand words: needs assessment for multimedia radiology reports in a large tertiary care medical center. Academic radiology Nayak, L., Beaulieu, C. F., Rubin, D. L., Lipson, J. A. 2013; 20 (12): 1577-1583
Abstract

Radiology reports are the major, and often only, means of communication between radiologists and their referring clinicians. The purposes of this study are to identify referring physicians' preferences about radiology reports and to quantify their perceived value of multimedia reports (with embedded images) compared with narrative text reports.We contacted 1800 attending physicians from a range of specialties at large tertiary care medical center via e-mail and a hospital newsletter linking to a 24-question electronic survey between July and November 2012. One hundred sixty physicians responded, yielding a response rate of 8.9%. Survey results were analyzed using Statistical Analysis Software (SAS Institute Inc, Cary, NC).Of the 160 referring physicians respondents, 142 (89%) indicated a general interest in reports with embedded images and completed the remainder of the survey questions. Of 142 respondents, 103 (73%) agreed or strongly agreed that reports with embedded images could improve the quality of interactions with radiologists; 129 respondents (91%) agreed or strongly agreed that having access to significant images enhances understanding of a text-based report; 110 respondents (77%) agreed or strongly agreed that multimedia reports would significantly improve referring physician satisfaction; and 85 respondents (60%) felt strongly or very strongly that multimedia reports would significantly improve patient care and outcomes.Creating accessible, readable, and automatic multimedia reports should be a high priority to enhance the practice and satisfaction of referring physicians, improve patient care, and emphasize the critical role radiology plays in current medical care.

View details for DOI 10.1016/j.acra.2013.09.002

View details for PubMedID 24200485
Modeling Perceptual Similarity Measures in CT Images of Focal Liver Lesions JOURNAL OF DIGITAL IMAGING Faruque, J., Rubin, D. L., Beaulieu, C. F., Napel, S. 2013; 26 (4): 714-720
Abstract

Motivation: A gold standard for perceptual similarity in medical images is vital to content-based image retrieval, but inter-reader variability complicates development. Our objective was to develop a statistical model that predicts the number of readers (N) necessary to achieve acceptable levels of variability. Materials and Methods: We collected 3 radiologists' ratings of the perceptual similarity of 171 pairs of CT images of focal liver lesions rated on a 9-point scale. We modeled the readers' scores as bimodal distributions in additive Gaussian noise and estimated the distribution parameters from the scores using an expectation maximization algorithm. We (a) sampled 171 similarity scores to simulate a ground truth and (b) simulated readers by adding noise, with standard deviation between 0 and 5 for each reader. We computed the mean values of 2-50 readers' scores and calculated the agreement (AGT) between these means and the simulated ground truth, and the inter-reader agreement (IRA), using Cohen's Kappa metric. Results: IRA for the empirical data ranged from =0.41 to 0.66. For between 1.5 and 2.5, IRA between three simulated readers was comparable to agreement in the empirical data. For these values , AGT ranged from =0.81 to 0.91. As expected, AGT increased with N, ranging from =0.83 to 0.92 for N = 2 to 50, respectively, with =2. Conclusion: Our simulations demonstrated that for moderate to good IRA, excellent AGT could nonetheless be obtained. This model may be used to predict the required N to accurately evaluate similarity in arbitrary size datasets.

View details for DOI 10.1007/s10278-012-9557-4

View details for Web of Science ID 000322434700017

View details for PubMedID 23254627
Quantifying the margin sharpness of lesions on radiological images for content-based image retrieval MEDICAL PHYSICS Xu, J., Nadel, S., Greenspan, H., Beaulieu, C. F., Agrawal, N., Rubin, D. 2012; 39 (9): 5405-5418
Abstract

To develop a method to quantify the margin sharpness of lesions on CT and to evaluate it in simulations and CT scans of liver and lung lesions.The authors computed two attributes of margin sharpness: the intensity difference between a lesion and its surroundings, and the sharpness of the intensity transition across the lesion boundary. These two attributes were extracted from sigmoid curves fitted along lines automatically drawn orthogonal to the lesion margin. The authors then represented the margin characteristics for each lesion by a feature vector containing histograms of these parameters. The authors created 100 simulated CT scans of lesions over a range of intensity difference and margin sharpness, and used the concordance correlation between the known parameter and the corresponding computed feature as a measure of performance. The authors also evaluated their method in 79 liver lesions (44 patients: 23 M, 21 F, mean age 61) and 58 lung nodules (57 patients: 24 M, 33 F, mean age 66). The methodology presented takes into consideration the boundary of the liver and lung during feature extraction in clinical images to ensure that the margin feature do not get contaminated by anatomy other than the normal organ surrounding the lesions. For evaluation in these clinical images, the authors created subjective independent reference standards for pairwise margin sharpness similarity in the liver and lung cohorts, and compared rank orderings of similarity used using our sharpness feature to that expected from the reference standards using mean normalized discounted cumulative gain (NDCG) over all query images. In addition, the authors compared their proposed feature with two existing techniques for lesion margin characterization using the simulated and clinical datasets. The authors also evaluated the robustness of their features against variations in delineation of the lesion margin by simulating five types of deformations of the lesion margin. Equivalence across deformations was assessed using Schuirmann's paired two one-sided tests.In simulated images, the concordance correlation between measured gradient and actual gradient was 0.994. The mean (s.d.) and standard deviation NDCG score for the retrieval of K images, K = 5, 10, and 15, were 84% (8%), 85% (7%), and 85% (7%) for CT images containing liver lesions, and 82% (7%), 84% (6%), and 85% (4%) for CT images containing lung nodules, respectively. The authors' proposed method outperformed the two existing margin characterization methods in average NDCG scores over all K, by 1.5% and 3% in datasets containing liver lesion, and 4.5% and 5% in datasets containing lung nodules. Equivalence testing showed that the authors' feature is more robust across all margin deformations (p < 0.05) than the two existing methods for margin sharpness characterization in both simulated and clinical datasets.The authors have described a new image feature to quantify the margin sharpness of lesions. It has strong correlation with known margin sharpness in simulated images and in clinical CT images containing liver lesions and lung nodules. This image feature has excellent performance for retrieving images with similar margin characteristics, suggesting potential utility, in conjunction with other lesion features, for content-based image retrieval applications.

View details for DOI 10.1118/1.4739507

View details for Web of Science ID 000309334500012

View details for PubMedID 22957608

View details for PubMedCentralID PMC3432101
A Comprehensive Descriptor of Shape: Method and Application to Content-Based Retrieval of Similar Appearing Lesions in Medical Images JOURNAL OF DIGITAL IMAGING Xu, J., Faruque, J., Beaulieu, C. F., Rubin, D., Napel, S. 2012; 25 (1): 121-128
Abstract

We have developed a method to quantify the shape of liver lesions in CT images and to evaluate its performance for retrieval of images with similarly-shaped lesions. We employed a machine learning method to combine several shape descriptors and defined similarity measures for a pair of shapes as a weighted combination of distances calculated based on each feature. We created a dataset of 144 simulated shapes and established several reference standards for similarity and computed the optimal weights so that the retrieval result agrees best with the reference standard. Then we evaluated our method on a clinical database consisting of 79 portal-venous-phase CT liver images, where we derived a reference standard of similarity from radiologists' visual evaluation. Normalized Discounted Cumulative Gain (NDCG) was calculated to compare this ordering with the expected ordering based on the reference standard. For the simulated lesions, the mean NDCG values ranged from 91% to 100%, indicating that our methods for combining features were very accurate in representing true similarity. For the clinical images, the mean NDCG values were still around 90%, suggesting a strong correlation between the computed similarity and the independent similarity reference derived the radiologists.

View details for DOI 10.1007/s10278-011-9388-8

View details for Web of Science ID 000304113400018

View details for PubMedID 21547518

View details for PubMedCentralID PMC3264721
Automatic annotation of radiological observations in liver CT images. AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium Gimenez, F., Xu, J., Liu, Y., Liu, T., Beaulieu, C., Rubin, D., Napel, S. 2012; 2012: 257-263
Abstract

We aim to predict radiological observations using computationally-derived imaging features extracted from computed tomography (CT) images. We created a dataset of 79 CT images containing liver lesions identified and annotated by a radiologist using a controlled vocabulary of 76 semantic terms. Computationally-derived features were extracted describing intensity, texture, shape, and edge sharpness. Traditional logistic regression was compared to L(1)-regularized logistic regression (LASSO) in order to predict the radiological observations using computational features. The approach was evaluated by leave one out cross-validation. Informative radiological observations such as lesion enhancement, hypervascular attenuation, and homogeneous retention were predicted well by computational features. By exploiting relationships between computational and semantic features, this approach could lead to more accurate and efficient radiology reporting.

View details for PubMedID 23304295
Managing Biomedical Image Metadata for Search and Retrieval of Similar Images JOURNAL OF DIGITAL IMAGING Korenblum, D., Rubin, D., Napel, S., Rodriguez, C., Beaulieu, C. 2011; 24 (4): 739-748
Abstract

Radiology images are generally disconnected from the metadata describing their contents, such as imaging observations ("semantic" metadata), which are usually described in text reports that are not directly linked to the images. We developed a system, the Biomedical Image Metadata Manager (BIMM) to (1) address the problem of managing biomedical image metadata and (2) facilitate the retrieval of similar images using semantic feature metadata. Our approach allows radiologists, researchers, and students to take advantage of the vast and growing repositories of medical image data by explicitly linking images to their associated metadata in a relational database that is globally accessible through a Web application. BIMM receives input in the form of standard-based metadata files using Web service and parses and stores the metadata in a relational database allowing efficient data query and maintenance capabilities. Upon querying BIMM for images, 2D regions of interest (ROIs) stored as metadata are automatically rendered onto preview images included in search results. The system's "match observations" function retrieves images with similar ROIs based on specific semantic features describing imaging observation characteristics (IOCs). We demonstrate that the system, using IOCs alone, can accurately retrieve images with diagnoses matching the query images, and we evaluate its performance on a set of annotated liver lesion images. BIMM has several potential applications, e.g., computer-aided detection and diagnosis, content-based image retrieval, automating medical analysis protocols, and gathering population statistics like disease prevalences. The system provides a framework for decision support systems, potentially improving their diagnostic accuracy and selection of appropriate therapies.

View details for DOI 10.1007/s10278-010-9328-z

View details for Web of Science ID 000292888700020

View details for PubMedID 20844917

View details for PubMedCentralID PMC3138941
Content-Based Image Retrieval in Radiology: Current Status and Future Directions JOURNAL OF DIGITAL IMAGING Akgul, C. B., Rubin, D. L., Napel, S., Beaulieu, C. F., Greenspan, H., Acar, B. 2011; 24 (2): 208-222
Abstract

Diagnostic radiology requires accurate interpretation of complex signals in medical images. Content-based image retrieval (CBIR) techniques could be valuable to radiologists in assessing medical images by identifying similar images in large archives that could assist with decision support. Many advances have occurred in CBIR, and a variety of systems have appeared in nonmedical domains; however, permeation of these methods into radiology has been limited. Our goal in this review is to survey CBIR methods and systems from the perspective of application to radiology and to identify approaches developed in nonmedical applications that could be translated to radiology. Radiology images pose specific challenges compared with images in the consumer domain; they contain varied, rich, and often subtle features that need to be recognized in assessing image similarity. Radiology images also provide rich opportunities for CBIR: rich metadata about image semantics are provided by radiologists, and this information is not yet being used to its fullest advantage in CBIR systems. By integrating pixel-based and metadata-based image feature analysis, substantial advances of CBIR in medicine could ensue, with CBIR systems becoming an important tool in radiology practice.

View details for DOI 10.1007/s10278-010-9290-9

View details for Web of Science ID 000288394700007

View details for PubMedID 20376525

View details for PubMedCentralID PMC3056970
High Hamstring Tendinopathy: MRI and Ultrasound Imaging and Therapeutic Efficacy of Percutaneous Corticosteroid Injection AMERICAN JOURNAL OF ROENTGENOLOGY Zissen, M. H., Wallace, G., Stevens, K. J., Fredericson, M., Beaulieu, C. F. 2010; 195 (4): 993-998
Abstract

The goals of this study were to review the MRI and sonographic findings in patients diagnosed clinically with high hamstring tendinopathy and to evaluate the efficacy of ultrasound-guided corticosteroid injections in providing symptomatic relief.MRI is more sensitive than ultrasound in detecting peritendinous edema and tendinopathy at the proximal hamstring origin. Fifty percent of patients had symptomatic improvement lasting longer than 1 month after percutaneous corticosteroid injection, and 24% of patients had symptom relief for more than 6 months.

View details for DOI 10.2214/AJR.09.3674

View details for PubMedID 20858830
Automated Retrieval of CT Images of Liver Lesions on the Basis of Image Similarity: Method and Preliminary Results RADIOLOGY Napel, S. A., Beaulieu, C. F., Rodriguez, C., Cui, J., Xu, J., Gupta, A., Korenblum, D., Greenspan, H., Ma, Y., Rubin, D. L. 2010; 256 (1): 243-252
Abstract

To develop a system to facilitate the retrieval of radiologic images that contain similar-appearing lesions and to perform a preliminary evaluation of this system with a database of computed tomographic (CT) images of the liver and an external standard of image similarity.Institutional review board approval was obtained for retrospective analysis of deidentified patient images. Thereafter, 30 portal venous phase CT images of the liver exhibiting one of three types of liver lesions (13 cysts, seven hemangiomas, 10 metastases) were selected. A radiologist used a controlled lexicon and a tool developed for complete and standardized description of lesions to identify and annotate each lesion with semantic features. In addition, this software automatically computed image features on the basis of image texture and boundary sharpness. Semantic and computer-generated features were weighted and combined into a feature vector representing each image. An independent reference standard was created for pairwise image similarity. This was used in a leave-one-out cross-validation to train weights that optimized the rankings of images in the database in terms of similarity to query images. Performance was evaluated by using precision-recall curves and normalized discounted cumulative gain (NDCG), a common measure for the usefulness of information retrieval.When used individually, groups of semantic, texture, and boundary features resulted in various levels of performance in retrieving relevant lesions. However, combining all features produced the best overall results. Mean precision was greater than 90% at all values of recall, and mean, best, and worst case retrieval accuracy was greater than 95%, 100%, and greater than 78%, respectively, with NDCG.Preliminary assessment of this approach shows excellent retrieval results for three types of liver lesions visible on portal venous CT images, warranting continued development and validation in a larger and more comprehensive database.

View details for DOI 10.1148/radiol.10091694

View details for Web of Science ID 000279106900029

View details for PubMedID 20505065

View details for PubMedCentralID PMC2897688
Current techniques in the performance, interpretation, and reporting of CT colonography. Gastrointestinal endoscopy clinics of North America Poullos, P. D., Beaulieu, C. F. 2010; 20 (2): 169-192
Abstract

The technical objective of computed tomographic colonography (CTC) is to acquire high-quality computed tomography images of the cleansed, well-distended colon for polyp detection. In this article the authors provide an overview of the technical components of CTC, from preparation of the patient to acquisition of the imaging data and basic methods of interpretation. In each section, the best evidence for current practices and recommendations is reviewed. Each of the technical components must be optimized to achieve high sensitivity in polyp detection.

View details for DOI 10.1016/j.giec.2010.02.007

View details for PubMedID 20451809
Imaging and Ultrasound-Guided Steroid Injection of Internal Oblique Muscle Strains in Baseball Pitchers AMERICAN JOURNAL OF SPORTS MEDICINE Stevens, K. J., Crain, J. M., Akizuki, K. H., Beaulieu, C. F. 2010; 38 (3): 581-585
Abstract

Internal oblique muscle injuries are common in professional baseball pitchers and may require a prolonged convalescence of up to 10 weeks. Most strains can be diagnosed clinically, but imaging can be helpful to assess the severity of injury, which may predict recovery and return to play.Ultrasound-guided injection of steroid and local anesthetic into the muscle tear can speed recovery and subsequent return to play.Case series; Level of evidence, 4.Three professional baseball pitchers with acute tears of the internal oblique muscle confirmed by magnetic resonance imaging underwent ultrasound-guided injection of steroid and local anesthetic.All 3 patients experienced significant pain relief within a few days of the injection and were able to pitch at full speed within 3 weeks of injury (mean, 21 days) and return to able status by 5 weeks (mean, 30.7 days). The 3 athletes continue to pitch in Major League Baseball 36 months, 36 months, and 14 months, respectively, after injury, and none have sustained reinjury during this time.Therapeutic injection of steroids and anesthetic under ultrasound guidance appears to speed recovery and rehabilitation in professional baseball pitchers with acute side strains.

View details for DOI 10.1177/0363546509350105

View details for PubMedID 20051499
EXTERNAL BEAM RADIATION THERAPY ENHANCES LOCAL CONTROL IN PIGMENTED VILLONODULAR SYNOVITIS INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS Horoschak, M., Tran, P. T., Bachireddy, P., West, R. B., Mohler, D., Beaulieu, C. F., Kapp, D. S., Donaldson, S. S. 2009; 75 (1): 183-187
Abstract

Pigmented villonodular synovitis (PVNS) is a rare proliferative disorder of the synovium with locally aggressive behavior. We reviewed our experience using radiation therapy in the treatment of PVNS.Seventeen patients with 18 sites of PVNS were treated with radiation between 1993 and 2007. Cases were retrospectively reviewed for patient information, treatment parameters, complications, and outcome. Seven sites were primary presentations and 11 were recurrent with an average of 2.5 prior surgical interventions. The most common location was the knee joint (67%). Cytoreductive surgery was performed before radiation therapy in 16/18 sites with all having proven or suspected residual disease. Radiation was delivered using 4-15 MV photons with an average total dose 34 Gy (range, 20-36 Gy). Seventeen of 18 sites (94%) had postradiotherapy imaging.With average follow-up of 46 months (range, 8-181 months), initial local control was achieved in 75% (12/16) of the sites with prior cytoreductive surgery (mean time to recurrence, 38 months). Ultimate local control was 100% after repeat resection (mean follow-up, 61 months). Two additional sites without prior cytoreductive surgery showed growth after radiotherapy (mean time to documented growth, 10.5 months). Seventeen of the 18 involved joints (94%) were scored as excellent or good PVNS-related function, one site (5%) as fair function, and no site with poor function. No patient required amputation; and there were no Grade 3/4 treatment-related complications.Postoperative external beam radiation is effective in preventing disease recurrence and should be offered following maximal cytoreduction to enhance local control in PVNS.

View details for DOI 10.1016/j.ijrobp.2008.10.058

View details for Web of Science ID 000269328700031

View details for PubMedID 19211195
Ankle: Isotropic MR Imaging with 3D-FSE-Cube-Initial Experience in Healthy Volunteers RADIOLOGY Stevens, K. J., Busse, R. F., Han, E., Brau, A. C., Beatty, P. J., Beaulieu, C. F., Gold, G. E. 2008; 249 (3): 1026-1033
Abstract

The purpose of this prospective study was to compare a new isotropic three-dimensional (3D) fast spin-echo (FSE) pulse sequence with parallel imaging and extended echo train acquisition (3D-FSE-Cube) with a conventional two-dimensional (2D) FSE sequence for magnetic resonance (MR) imaging of the ankle. After institutional review board approval and informed consent were obtained and in accordance with HIPAA privacy guidelines, MR imaging was performed in the ankles of 10 healthy volunteers (four men, six women; age range, 25-41 years). Imaging with the 3D-FSE-Cube sequence was performed at 3.0 T by using both one-dimensional- and 2D-accelerated autocalibrated parallel imaging to decrease imaging time. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) with 3D-FSE-Cube were compared with those of the standard 2D FSE sequence. Cartilage, muscle, and fluid SNRs were significantly higher with the 3D-FSE-Cube sequence (P < .01 for all). Fluid-cartilage CNR was similar for both techniques. The two sequences were also compared for overall image quality, blurring, and artifacts. No significant difference for overall image quality and artifacts was demonstrated between the 2D FSE and 3D-FSE-Cube sequences, although the section thickness in 3D-FSE-Cube imaging was much thinner (0.6 mm). However, blurring was significantly greater on the 3D-FSE-Cube images (P < .04). The 3D-FSE-Cube sequence with isotropic resolution is a promising new MR imaging sequence for viewing complex joint anatomy.

View details for DOI 10.1148/radiol.2493080227

View details for PubMedID 19011194
All-in-one magnetic resonance arthrography of the shoulder in a vertically open magnetic resonance unit ACTA RADIOLOGICA Vandevenne, J. E., Vanhoenacker, F., Beaulieu, C. F., Bergman, A. G., Pauly, K. B., Dillingham, M. F., Lang, P. K. 2008; 49 (8): 918-927
Abstract

Magnetic resonance (MR) arthrography frequently involves joint injection under imaging guidance followed by MR imaging in static positions.To evaluate if MR arthrography of the shoulder joint can be performed in a comprehensive fashion combining the MR-guided injection procedure, static MR imaging, and dynamic motion MR imaging in a single test.Twenty-three shoulder joints were injected with Gd-DTPA2- under MR guidance. Static MR imaging was performed and included a three-point Dixon method to achieve water-selective images. Dynamic motion MR imaging with and without applying pressure to the upper arm was used to evaluate glenohumeral joint instability. In 10 cases, surgical correlation was available.The all-in-one MR arthrography technique was successful in all patients, and took an average time of 65 min. All but one glenohumeral injection procedure were performed with a single needle pass, and no complications were observed. Out of eight labrum tears seen with static MR imaging, seven were confirmed at surgery. In 10 cases, dynamic motion MR imaging correlated well with the surgeon's intraoperative evaluation for presence and direction of instability.MR arthrography of the shoulder joint using a vertically open magnet can be performed as a single comprehensive test, including the injection and the static and dynamic motion MR imaging. Good diagnostic accuracy for intraarticular lesions and glenohumeral instability was found in a small sample.

View details for DOI 10.1080/02841850802291242

View details for Web of Science ID 000260046200011

View details for PubMedID 18651257
Tibial aperture bone disruption after retrograde versus antegrade tibial tunnel drilling: a cadaveric study KNEE SURGERY SPORTS TRAUMATOLOGY ARTHROSCOPY McAdams, T. R., Biswal, S., Stevens, K. J., Beaulieu, C. F., Mandelbaum, B. R. 2008; 16 (9): 818-822
Abstract

The purpose of this study is to compare the local microfracture effects of antegrade versus retrograde drilling of the tibial tunnel in ACL reconstruction. Arthroscopic ACL excision was performed on eight matched cadaveric knees. Arthroscopic guided tibial tunnel reaming was performed in either an antegrade (four) or retrograde (four) direction. A 3 x 3 cm section of proximal tibial surrounding the tibial aperture was removed with open dissection, and each section underwent micro-computed tomography analysis. Three musculoskeletal radiologists graded the specimens for bone aperture disruption and discrete fracture lines. Tibial aperture irregularity was seen in all four of the antegrade specimens (mean, Grade 1.5), and in none of the retrograde specimens. Discrete fracture lines were present in all four antegrade specimens (mean 10.13 mm depth; 8.95 mm length). No fracture lines were seen in the retrograde group. Retrograde drilling of the tibial tunnel in ACL reconstruction results in less microfracture trauma to the surrounding aperture bone. The use of retrograde drilling in ACL reconstruction may decrease synovialization of the graft-tissue interface when compared to antegrade drilling.

View details for DOI 10.1007/s00167-008-0554-6

View details for PubMedID 18516594
Stress-related injuries around the lesser trochanter in long-distance runners AMERICAN JOURNAL OF ROENTGENOLOGY Nguyen, J. T., Peterson, J. S., Biswal, S., Beaulieu, C. F., Fredericson, M. 2008; 190 (6): 1616-1620
Abstract

Imaging abnormalities around the lesser trochanter are occasionally found in long-distance runners, yet little research has been conducted concerning this area of the hip. In addition, the relation between iliopsoas insertional abnormalities at the lesser trochanter and femoral neck stress injuries has not been examined, to our knowledge. We report MRI findings at the lesser trochanter in nine long-distance runners with hip or groin pain and a consistent constellation of the following findings: abnormalities associated with the iliopsoas tendon and its insertion, including marrow edema at the lesser trochanter; periostitis around the lesser trochanter; and bone marrow edema in the femoral neck. One case involved temporal progression to a cortical fracture.Long-distance runners with hip or groin pain and abnormal MRI findings involving the insertion of the iliopsoas tendon and marrow edema in the lesser trochanter may be at risk of stress injuries at the femoral neck.

View details for DOI 10.2214/AJR.07.2513

View details for Web of Science ID 000256064700035

View details for PubMedID 18492915
Colon polyp detection using smoothed shape operators: Preliminary results MEDICAL IMAGE ANALYSIS Sundaram, P., Zomorodian, A., Beaulieu, C., Napel, S. 2008; 12 (2): 99-119
Abstract

Computer-aided detection (CAD) algorithms identify locations in computed tomographic (CT) images of the colon that are most likely to contain polyps. Existing CAD methods treat the CT data as a voxelized, volume image. They estimate a curvature-based feature at the mucosal surface voxels. However, curvature is a smooth notion, while our data are discrete and noisy. As a second order differential quantity, curvature amplifies noise. In this paper, we present the smoothed shape operators method (SSO), which uses a geometry processing approach. We extract a triangle mesh representation of the colon surface, and estimate curvature on this surface using the shape operator. We then smooth the shape operators on the surface iteratively. Throughout, we use techniques explicitly designed for discrete geometry. All our computation occurs on the surface, rather than in the voxel grid. We evaluate our algorithm on patient data and provide free-response receiver-operating characteristic performance analysis over all size ranges of polyps. We also provide confidence intervals for our performance estimates. We compare our performance with the surface normal overlap (SNO) method for the same data. A preliminary evaluation of our method on 35 patients yielded the following results (polyp diameter range; sensitivity; false positives/case): (10mm; 100%; 17.5), (5-10 mm; 89.7%, 21.23), (<5 mm; 59.1%; 23.9) and (overall; 80.3%; 23.9). The evaluation of the SNO method yielded: (10 mm; 75%; 17.5), (5-10 mm; 43.1%; 21.23), (<5 mm; 15.9%; 23.9) and (overall; 38.5%; 23.9).

View details for DOI 10.1016/j.media.2007.08.001

View details for Web of Science ID 000256156500002

View details for PubMedID 17910934
iPad: Semantic annotation and markup of radiological images. AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium Rubin, D. L., Rodriguez, C., Shah, P., Beaulieu, C. 2008: 626-630
Abstract

Radiological images contain a wealth of information,such as anatomy and pathology, which is often not explicit and computationally accessible. Information schemes are being developed to describe the semantic content of images, but such schemes can be unwieldy to operationalize because there are few tools to enable users to capture structured information easily as part of the routine research workflow. We have created iPad, an open source tool enabling researchers and clinicians to create semantic annotations on radiological images. iPad hides the complexity of the underlying image annotation information model from users, permitting them to describe images and image regions using a graphical interface that maps their descriptions to structured ontologies semi-automatically. Image annotations are saved in a variety of formats,enabling interoperability among medical records systems, image archives in hospitals, and the Semantic Web. Tools such as iPad can help reduce the burden of collecting structured information from images, and it could ultimately enable researchers and physicians to exploit images on a very large scale and glean the biological and physiological significance of image content.

View details for PubMedID 18999144

View details for PubMedCentralID PMC2655990
Polyp enhancing level set evolution of colon wall: Method and pilot study IEEE TRANSACTIONS ON MEDICAL IMAGING Konukoglu, E., Acar, B., Paik, D. S., Beaulieu, C. F., Rosenberg, J., Napel, S. 2007; 26 (12): 1649-1656
Abstract

Computer aided detection (CAD) in computed tomography colonography (CTC) aims at detecting colonic polyps that are the precursors of colon cancer. In this work, we propose a colon wall evolution algorithm polyp enhancing level sets (PELS) based on the level-set formulation that regularizes and enhances polyps as a preprocessing step to CTC CAD algorithms. The underlying idea is to evolve the polyps towards spherical protrusions on the colon wall while keeping other structures, such as haustral folds, relatively unchanged and, thereby, potentially improve the performance of CTC CAD algorithms, especially for smaller polyps. To evaluate our methods, we conducted a pilot study using an arbitrarily chosen CTC CAD method, the surface normal overlap (SNO) CAD algorithm, on a nine patient CTC data set with 47 polyps of sizes ranging from 2.0 to 17.0 mm in diameter. PELS increased the maximum sensitivity by 8.1% (from 21/37 to 24/37) for small polyps of sizes ranging from 5.0 to 9.0 mm in diameter. This is accompanied by a statistically significant separation between small polyps and false positives. PELS did not change the CTC CAD performance significantly for larger polyps.

View details for DOI 10.1109/TMI.2007.901429

View details for Web of Science ID 000251376500004

View details for PubMedID 18092735
Abduction and external rotation in shoulder impingement: An open MR study on healthy volunteers - Initial experience RADIOLOGY Gold, G. E., Pappas, G. P., Blemker, S. S., Whalen, S. T., Campbell, G., McAdams, T. A., Beaulieu, C. F. 2007; 244 (3): 815-822
Abstract

To prospectively evaluate rotator cuff contact with the glenoid in healthy volunteers placed in the unloaded and loaded abduction and external rotation (ABER) positions in an open magnetic resonance (MR) imager.The study was institutional review board approved and HIPAA compliant, and informed consent was received. Eight male volunteers with no history of shoulder pain or pathology were imaged in a 0.5-T open MR imager. Volunteers were imaged in an unloaded ABER position with the arm at 90 degrees abduction and in a loaded ABER position, with a 1-kg load that produced an average external rotation of 111 degrees+/-6 (standard deviation). Two radiologists graded rotator cuff contact on a three-point scale. Three-dimensional anatomic models generated from the MR images were used to measure distances. Minimum distances were computed between the tendon insertion sites and the glenoid, acromion, and coracoid for the loaded ABER position. Minimum distances were compared by using a paired Student t test.In the unloaded ABER position, contact was seen between the infraspinatus and supraspinatus tendons and the glenoid in all eight volunteers. In the loaded ABER position, contact was also observed between the infraspinatus and supraspinatus and the posterior and posterosuperior glenoid, respectively. Deformation of the infraspinatus on the glenoid was seen in four volunteers, whereas supraspinatus deformation was only seen in one volunteer. The minimum distance between the supraspinatus insertion and acromion in the loaded ABER position decreased significantly (P<.01). Supraspinatus tendon to glenoid and infraspinatus tendon to glenoid minimum distances also decreased significantly (P<.01).The unloaded and loaded ABER positions resulted in contact of the supraspinatus and infraspinatus with the glenoid in all volunteers. Distances between the rotator cuff insertion sites and the glenoid decreased in the loaded ABER position.

View details for DOI 10.1148/radiol.2443060998

View details for PubMedID 17690321
Transparent rendering of intraluminal contrast for 3D polyp visualization at CT colonography JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Shi, R., Napel, S., Rosenberg, J. K., Shin, L. K., Walsh, C. F., Mogensen, M. A., Joshi, A. J., Pankhudi, P., Beaulieu, C. F. 2007; 31 (5): 773-779
Abstract

We developed a classifier that permits transparent rendering of both tagging material and air to facilitate interpretation of tagged computed tomographic (CT) colonography. With this technique, a reader can simultaneously appreciate polyps on endoluminal views both covered with tagging material and against air, along with unmodified 2-dimensional CT images. Evaluated with 49 polyps from 26 patients (data from public National Library of Medicine, Health Insurance Portability and Accountability Act compliant), 3 readers were able to determine the presence/absence of polyps in tagged locations with equivalent accuracy compared with polyps in air. This method offers an alternative way to visualize tagged CT colonography.

View details for Web of Science ID 000249964800020

View details for PubMedID 17895791
Isotropic MRI of the knee with 3D fast spin-echo extended echo-train acquisition (XETA): Initial experience AMERICAN JOURNAL OF ROENTGENOLOGY Gold, G. E., Busse, R. F., Beehler, C., Han, E., Brau, A. C., Beatty, P. J., Beaulieu, C. F. 2007; 188 (5): 1287-1293
Abstract

The purpose of our study was to prospectively compare a recently developed method of isotropic 3D fast spin-echo (FSE) with extended echo-train acquisition (XETA) with 2D FSE and 2D fast recovery FSE (FRFSE) for MRI of the knee.Institutional review board approval, Health Insurance Portability and Accounting Act (HIPAA) compliance, and informed consent were obtained. We studied 10 healthy volunteers and one volunteer with knee pain using 3D FSE XETA, 2D FSE, and 2D FRFSE. Images were obtained both with and without fat suppression. Cartilage and muscle signal-to-noise ratio (SNR) and cartilage-fluid contrast-to-noise ratio (CNR) were compared using a Student's t test. We also compared reformations of 3D FSE XETA with 2D FSE images directly acquired in the axial plane.Cartilage SNR was higher with 3D FSE XETA (56.8 +/- 9 [SD]) compared with the 2D FSE (45.8 +/- 8, p < 0.01) and 2D FRFSE (32.5 +/- 5.3, p < 0.01). Muscle SNR was significantly higher with 3D FSE XETA (52.1 +/- 4.3) than 2D FSE (45.2 +/- 9, p < 0.01) and 2D FRFSE (23.6 +/- 6.2, p < 0.01). Fluid SNR was significantly higher for 2D FSE (144.9 +/- 33) than 3D FSE XETA (104.7 +/- 18, p < 0.01). Compared with 2D FSE and 2D FRFSE, 3D FSE XETA had lower cartilage-fluid CNR due to higher cartilage SNR (p < 0.01). Three-dimensional FSE XETA acquired volumetric data sets with isotropic resolution. Reformatted images in the axial plane were similar to axial 2D FSE acquisitions but with thinner slices.Three-dimensional FSE XETA acquires high-resolution (approximately 0.7 mm) isotropic data with intermediate and T2-weighting that may be reformatted in arbitrary planes. Three-dimensional FSE XETA is a promising technique for MRI of the knee.

View details for DOI 10.2214/AJR.06.1208

View details for Web of Science ID 000246013000027

View details for PubMedID 17449772
Balanced SSFP imaging of the musculoskeletal system JOURNAL OF MAGNETIC RESONANCE IMAGING Gold, G. E., Hargreaves, B. A., Reeder, S. B., Block, W. F., Kijowski, R., Vasanawala, S. S., Kornaat, P. R., Bammer, R., Newbould, R., Bangerter, N. K., Beaulieu, C. F. 2007; 25 (2): 270-278
Abstract

Magnetic resonance imaging (MRI), with its unique ability to image and characterize soft tissue noninvasively, has emerged as one of the most accurate imaging methods available to diagnose bone and joint pathology. Currently, most evaluation of musculoskeletal pathology is done with two-dimensional acquisition techniques such as fast spin echo (FSE) imaging. The development of three-dimensional fast imaging methods based on balanced steady-state free precession (SSFP) shows great promise to improve MRI of the musculoskeletal system. These methods may allow acquisition of fluid sensitive isotropic data that can be reformatted into arbitrary planes for improved detection and visualization of pathology. Sensitivity to fluid and fat suppression are important issues in these techniques to improve delineation of cartilage contours, for detection of marrow edema and derangement of other joint structures.

View details for DOI 10.1002/jmri.20819

View details for Web of Science ID 000244133000006

View details for PubMedID 17260387
Iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) fast spin-echo imaging of the ankle: Initial clinical experience AMERICAN JOURNAL OF ROENTGENOLOGY Fuller, S., Reeder, S., Shimakawa, A., Yu, H., Johnson, J., Beaulieu, C., Gold, G. E. 2006; 187 (6): 1442-1447
Abstract

Reliable, uniform fat suppression is important. Multiple approaches currently exist, many of which suffer from either suboptimal signal-to-noise ratio (SNR), or the inability to obtain consistent fat suppression around the ankle joint. Our purpose was to test iterative decomposition of water and fat with echo asymmetry and the least-squares estimation (IDEAL) method in combination with fast spin-echo imaging, which is able to achieve reliable high SNR images with uniform fat-water separation.We compared IDEAL fast spin-echo with conventional fat-suppressed fast spin-echo imaging in 33 ankles in 32 patients. Quantitative measurements of SNR and contrast-to-noise ratio efficiency were made, and qualitative diagnostic image quality and fat-suppression scores were determined.We found that the SNR efficiency for both cartilage and fluid was similar for both techniques, and fluid/cartilage contrast-to-noise ratio efficiency was higher with IDEAL fast spin-echo imaging. Fat suppression and diagnostic quality scores using the IDEAL method were superior (p < 0.01) to fat-suppressed fast spin-echo imaging.IDEAL fast spin-echo imaging is a promising technique for MRI of the ankle.

View details for DOI 10.2214/AJR.05.0930

View details for Web of Science ID 000242289200010

View details for PubMedID 17114534
Ligament and tendon injury to the elbow: clinical, surgical, and imaging features. Topics in magnetic resonance imaging Saliman, J. D., Beaulieu, C. F., McAdams, T. R. 2006; 17 (5): 327-336
Abstract

Significant advances in the understanding of elbow anatomy, biomechanics, imaging, and surgical technique have been made over the last decade. Tendon injuries are often seen in athletes and physical laborers from repetitive eccentric overload. Ligament injuries are commonly seen in throwing athletes or after elbow dislocation. Magnetic resonance imaging has proven valuable for diagnosing and monitoring most of these soft tissue injuries, and effective surgical techniques have evolved to address them. This article describes typical clinical findings associated with ligament and tendon injuries in the elbow as well as common surgical therapies. The use of magnetic resonance imaging is highlighted throughout because this modality has revolutionized noninvasive evaluation of the elbow.

View details for PubMedID 17414994
Stress fractures in athletes. Topics in magnetic resonance imaging Fredericson, M., Jennings, F., Beaulieu, C., Matheson, G. O. 2006; 17 (5): 309-325
Abstract

A stress fracture is a partial or complete bone fracture that results from repeated application of stress lower than the stress required to fracture the bone in a single loading. Otherwise healthy athletes, especially runners, sustain stress injuries or fractures. Prevention or early intervention is the preferable treatment. However, it is difficult to predict injury because runners vary with regard to biomechanical predisposition, training methods, and other factors such as diet, muscle strength, and flexibility. Stress fractures account for 0.7% to 20% of all sports medicine clinic injuries. Track-and-field athletes have the highest incidence of stress fractures compared with other athletes. Stress fractures of the tibia, metatarsals, and fibula are the most frequently reported sites. The sites of stress fractures vary from sport to sport (eg, among track athletes, stress fractures of the navicular, tibia, and metatarsal are common; in distance runners, it is the tibia and fibula; in dancers, the metatarsals). In the military, the calcaneus and metatarsals were the most commonly cited injuries, especially in new recruits, owing to the sudden increase in running and marching without adequate preparation. However, newer studies from the military show the incidence and distribution of stress fractures to be similar to those found in sports clinics. Fractures of the upper extremities are relatively rare, although most studies have focused only on lower-extremity injuries. The ulna is the upper-extremity bone injured most frequently. Imaging plays a key role in the diagnosis and management of stress injuries. Plain radiography is useful when positive, but generally has low sensitivity. Radionuclide bone scanning is highly sensitive, but lacks specificity and the ability to directly visualize fracture lines. In this article, we focus on magnetic resonance imaging, which provides highly sensitive and specific evaluation for bone marrow edema, periosteal reaction as well as detection of subtle fracture lines.

View details for PubMedID 17414993
T-1- and T-2-weighted fast spin-echo imaging of the brachial plexus and cervical spine with IDEAL water-fat separation JOURNAL OF MAGNETIC RESONANCE IMAGING Reeder, S. B., Yu, H., Johnson, J. W., Shimakawa, A., Brittain, J. H., Pelc, N. J., Beaulieu, C. F., Gold, G. E. 2006; 24 (4): 825-832
Abstract

To compare the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) method with fat-saturated T1-weighted (T1W) and T2W fast spin-echo (FSE) and short-TI inversion recovery (STIR) imaging of the brachial plexus and cervical spine.Images acquired at 1.5T in five volunteers using fat-saturated T1W and T2W FSE imaging and STIR were compared with T1W and T2W IDEAL-FSE images. Examples of T1W and T2W IDEAL-FSE images acquired in patients are also shown.T1W and T2W IDEAL-FSE demonstrated superior fat suppression (P<0.05) and image quality (P<0.05), compared to T1W and T2W fat-saturated FSE, respectively. SNR performance of T1W-IDEAL-FSE was similar to T1W FSE in the spinal cord (P=0.250) and paraspinous muscles (P=0.78), while T2W IDEAL-FSE had superior SNR in muscle (P=0.02) and CSF (P=0.02), and marginally higher cord SNR (P=0.09). Compared to STIR, T2W IDEAL-FSE demonstrated superior image quality (P<0.05), comparable fat suppression (excellent, P=1.0), and higher SNR performance (P<0.001).IDEAL-FSE is a promising method for T1W and T2W imaging of the brachial plexus and cervical spine.

View details for DOI 10.1002/jmri.20721

View details for Web of Science ID 000240882000013

View details for PubMedID 16969792
Articular cartilage of the knee: Rapid three-dimensional MR imaging at 3.0 T with IDEAL balanced steady-State free precession - Initial experience RADIOLOGY Gold, G. E., Reeder, S. B., Yu, H., Kornaat, P., Shimakawa, A. S., Johnson, J. W., Pelc, N. J., Beaulieu, C. F., Brittain, J. H. 2006; 240 (2): 546-551
Abstract

Institutional review board approval and informed consent were obtained for this HIPAA-compliant study. In this study, iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL) balanced steady-state free precession (bSSFP), fat-suppressed bSSFP, and fat-suppressed spoiled gradient-echo (GRE) sequences for 3.0-T magnetic resonance (MR) imaging of articular knee cartilage were prospectively compared in five healthy volunteers. Cartilage and fluid signal-to-noise ratio (SNR), cartilage-fluid contrast-to-noise ratio (CNR), SNR efficiency, CNR efficiency, image quality, and fat suppression were compared. Fat-suppressed bSSFP and IDEAL bSSFP had higher SNR efficiency of cartilage (P < .01) than did GRE. IDEAL bSSFP had higher cartilage-fluid CNR efficiency than did fat-suppressed bSSFP or GRE (P < .01). Fat-suppressed bSSFP and IDEAL bSSFP had higher image quality than did GRE (P < .01). GRE and IDEAL bSSFP had significantly better fat-water separation or fat saturation than did fat-suppressed bSSFP (P < .05). IDEAL bSSFP is a promising method for imaging articular knee cartilage.

View details for DOI 10.1148/radiol.2402050288

View details for Web of Science ID 000239242600029

View details for PubMedID 16801369
Advanced magnetic resonance imaging of articular cartilage ORTHOPEDIC CLINICS OF NORTH AMERICA Gold, G. E., Hargreaves, B. A., Stevens, K. J., Beaulieu, C. F. 2006; 37 (3): 331-?
Abstract

MRI is one of the most accurate imaging methods available to diagnose disorders of articular cartilage. Conventional two-dimensional and three-dimensional approaches show changes in cartilage morphology. Newer and substantially faster three-dimensional imaging methods show great promise to improve MRI of cartilage. These methods may allow acquisition of fluid-sensitive isotropic data that can be reformatted into arbitrary planes for improved detection and visualization of pathology. Unique MRI contrast mechanisms also allow clinicians to probe cartilage physiology and detect early changes in cartilage macromolecules.

View details for DOI 10.1016/j.ocl.2006.04.006

View details for PubMedID 16846765
"Flying through" and "flying around" a PET/CT scan: Pilot study and development of 3D integrated F-18-FDG PET/CT for virtual bronchoscopy and colonoscopy JOURNAL OF NUCLEAR MEDICINE Quon, A., Napel, S., Beaulieu, C. F., Gambhir, S. S. 2006; 47 (7): 1081-1087
Abstract

The objective of this pilot project was to devise a new image acquisition and processing technique to produce PET/CT images rendered in 3-dimensional (3D) volume that can then be reviewed in several 3D formats such as virtual bronchoscopy and colonoscopy "fly-throughs" and external "fly-arounds."We tested the new imaging and processing protocol on 24 patients with various malignancies to determine whether it could dependably acquire and reformat standard tomographic 2-dimensional PET/CT images into 3D renderings.This new technique added helpful information to the diagnostic interpretation for 2 of the 24 patients. Further, in the 6 patients undergoing mediastinoscopy, bronchoscopy, or endoscopy, 3D imaging helped in preprocedural planning.In this initial study, we demonstrated both the feasibility of rendering PET/CT images into 3D volumes and the potential clinical utility of this technique for diagnostic lesion characterization and preprocedural planning.

View details for Web of Science ID 000238879300008

View details for PubMedID 16818940
CT colonography: Influence of 3D viewing and polyp candidate features on interpretation with computer-aided detection RADIOLOGY Shi, R., Schraedley-Desmond, P., Napel, S., Olcott, E. W., Jeffrey, R. B., Yee, J., Zalis, M. E., Margolis, D., Paik, D. S., Sherbondy, A. J., Sundaram, P., Beaulieu, C. F. 2006; 239 (3): 768-776
Abstract

To retrospectively determine if three-dimensional (3D) viewing improves radiologists' accuracy in classifying true-positive (TP) and false-positive (FP) polyp candidates identified with computer-aided detection (CAD) and to determine candidate polyp features that are associated with classification accuracy, with known polyps serving as the reference standard.Institutional review board approval and informed consent were obtained; this study was HIPAA compliant. Forty-seven computed tomographic (CT) colonography data sets were obtained in 26 men and 10 women (age range, 42-76 years). Four radiologists classified 705 polyp candidates (53 TP candidates, 652 FP candidates) identified with CAD; initially, only two-dimensional images were used, but these were later supplemented with 3D rendering. Another radiologist unblinded to colonoscopy findings characterized the features of each candidate, assessed colon distention and preparation, and defined the true nature of FP candidates. Receiver operating characteristic curves were used to compare readers' performance, and repeated-measures analysis of variance was used to test features that affect interpretation.Use of 3D viewing improved classification accuracy for three readers and increased the area under the receiver operating characteristic curve to 0.96-0.97 (P<.001). For TP candidates, maximum polyp width (P=.038), polyp height (P=.019), and preparation (P=.004) significantly affected accuracy. For FP candidates, colonic segment (P=.007), attenuation (P<.001), surface smoothness (P<.001), distention (P=.034), preparation (P<.001), and true nature of candidate lesions (P<.001) significantly affected accuracy.Use of 3D viewing increases reader accuracy in the classification of polyp candidates identified with CAD. Polyp size and examination quality are significantly associated with accuracy.

View details for Web of Science ID 000237738600018

View details for PubMedID 16714460
Articular cartilage of the knee: Evaluation with fluctuating equilibrium MR imaging - Initial experience in healthy volunteers RADIOLOGY Gold, G. E., Hargreaves, B. A., Vasanawala, S. S., Webb, J. D., Shimakawa, A. S., Brittain, J. H., Beaulieu, C. F. 2006; 238 (2): 712-718
Abstract

Institutional review board approval and informed consent were obtained for this HIPAA-compliant study, whose purpose was to prospectively compare three magnetic resonance (MR) imaging techniques-fluctuating equilibrium, three-dimensional (3D) spoiled gradient-recalled acquisition in the steady state (SPGR), and two-dimensional (2D) fast spin echo (SE)-for evaluating articular cartilage in the knee. The study cohort consisted of 10 healthy volunteers (four men, six women; age range, 26-42 years). Cartilage signal-to-noise ratio (SNR), SNR efficiency, cartilage-fluid contrast-to-noise ratio (CNR), CNR efficiency, image quality, cartilage visibility, and fat suppression were compared. Cartilage volume was compared for the fluctuating equilibrium and 3D SPGR techniques. Compared with 3D SPGR and 2D fast SE, fluctuating equilibrium yielded the highest cartilage SNR efficiency and cartilage-fluid CNR efficiency (P < .01 for both). Image quality was similar with all sequences. Fluctuating equilibrium imaging yielded higher cartilage visibility than did 2D fast SE imaging (P <. 01) but worse fat suppression than did 3D SPGR and 2D fast SE imaging (P < .04). Cartilage volume measurements with fluctuating equilibrium and 3D SPGR were similar. Fluctuating equilibrium MR imaging is a promising method for evaluating articular cartilage in the knee.

View details for DOI 10.1148/radiol.2381042183

View details for Web of Science ID 000234859100040

View details for PubMedID 16436826
In vivo anatomy of the Neer and Hawkins sign positions for shoulder impingement JOURNAL OF SHOULDER AND ELBOW SURGERY Pappas, G. P., Blemker, S. S., Beaulieu, C. F., McAdams, T. R., Whalen, S. T., Gold, G. E. 2006; 15 (1): 40-49
Abstract

The Neer and Hawkins impingement signs are commonly used to diagnose subacromial pathology, but the anatomy of these maneuvers has not been well elucidated in vivo. This 3-dimensional open magnetic resonance imaging study characterized shoulder anatomy and rotator cuff impingement in 8 normal volunteers placed in the Neer and Hawkins positions. Subacromial and intraarticular contact of the rotator cuff was graded, and minimum distances were computed between the tendon insertion sites and the glenoid, acromion, and coracoid. Both the Neer and Hawkins maneuvers significantly decreased the distance from the supraspinatus insertion to the acromion and posterior glenoid and from the subscapularis insertion to the anterior glenoid. However, the Hawkins position resulted in significantly greater subacromial space narrowing and subacromial rotator cuff contact than the Neer position. In the Hawkins position, subacromial contact of the supraspinatus and infraspinatus was observed in 7 of 8 and 5 of 8 subjects, respectively. In contrast, rotator cuff contact with the acromion did not occur in any subject in the Neer position. Intraarticular contact of the supraspinatus with the posterosuperior glenoid was observed in all subjects in both positions. Subscapularis contact with the anterior glenoid was also seen in 7 of 8 subjects in the Neer position and in all subjects in the Hawkins position. This extensive intraarticular contact suggests that internal impingement may play a role in the Neer and Hawkins signs.

View details for DOI 10.1016/j.jse.2005.04.007

View details for PubMedID 16414467
Iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL): Application with fast spin-echo imaging MAGNETIC RESONANCE IN MEDICINE Reeder, S. B., Pineda, A. R., Wen, Z. F., Shimakawa, A., Yu, H. Z., Brittain, J. H., Gold, G. E., Beaulieu, C. H., Pelc, N. J. 2005; 54 (3): 636-644
Abstract

Chemical shift based methods are often used to achieve uniform water-fat separation that is insensitive to Bo inhomogeneities. Many spin-echo (SE) or fast SE (FSE) approaches acquire three echoes shifted symmetrically about the SE, creating time-dependent phase shifts caused by water-fat chemical shift. This work demonstrates that symmetrically acquired echoes cause artifacts that degrade image quality. According to theory, the noise performance of any water-fat separation method is dependent on the proportion of water and fat within a voxel, and the position of echoes relative to the SE. To address this problem, we propose a method termed "iterative decomposition of water and fat with echo asymmetric and least-squares estimation" (IDEAL). This technique combines asymmetrically acquired echoes with an iterative least-squares decomposition algorithm to maximize noise performance. Theoretical calculations predict that the optimal echo combination occurs when the relative phase of the echoes is separated by 2pi/3, with the middle echo centered at pi/2+pik (k=any integer), i.e., (-pi/6+pik, pi/2+pik, 7pi/6+pik). Only with these echo combinations can noise performance reach the maximum possible and be independent of the proportion of water and fat. Close agreement between theoretical and experimental results obtained from an oil-water phantom was observed, demonstrating that the iterative least-squares decomposition method is an efficient estimator.

View details for DOI 10.1002/mrm.20624

View details for Web of Science ID 000231494000015

View details for PubMedID 16092103
The flexor hallucis longus: Tenographic technique and correlation of Imaging findings with surgery in 39 ankles RADIOLOGY Na, J. B., Bergman, A. G., Oloff, L. M., Beaulieu, C. F. 2005; 236 (3): 974-982
Abstract

To examine the use of tenography for evaluation of the flexor hallucis longus (FHL) sheath.Institutional review board approval was waived, patient consent was obtained, and the study was HIPAA compliant. Retrospective review of 192 FHL tenograms and associated surgical records identified 39 ankles in 37 patients (17 male, 20 female; mean age +/- standard deviation, 38 years +/- 13.8; range, 14-68 years) in which both tenography and surgery had been performed. Two radiologists reviewed tenographic findings, including contrast agent extravasation, synovial irregularity, stenosis, fibrous bands, sheath outpouching, extent of opacification, and communications with adjacent structures. Alterations in pain after anesthesia of the tendon sheath were also recorded. Surgical reports were reviewed.Thirty-four of 39 tenograms were diagnostic. Some extravasation occurred in nine (45%) of 20 injections with an initial injection method and in two (11%) of 19 with a new injection technique. Synovial irregularity was present in all 34 studies (15 mild, 16 moderate, three severe). Stenoses were identified in 23 (68%) of 34 ankles, fibrous bands were seen in 16 (47%) of 34 ankles, and outpouching of the sheath above a stenosis was present in 13 (38%) of 34 ankles. Communication of the FHL sheath with the ankle, flexor digitorum longus, or subtalar joint occurred in half the cases. Most patients with pain reported relief; relief was complete (100% reduction from preprocedural pain) in eight of 27, moderate (50%-90% reduction) in nine of 27, and mild (<50% reduction) in eight of 27 patients.Tenography of the FHL sheath produced diagnostic images in almost all patients and effectively demonstrated abnormalities of the tendon sheath. Pain relief with anesthetic injection helped confirm the FHL sheath as the pain generator.

View details for DOI 10.1148/radiol.2362040835

View details for Web of Science ID 000231412600031

View details for PubMedID 16118172
MRI findings of femoral diaphyseal stress injuries in athletes AMERICAN JOURNAL OF ROENTGENOLOGY Hwang, B., Fredericson, M., Chung, C. B., Beaulieu, C. F., Gold, G. E. 2005; 185 (1): 166-173
View details for Web of Science ID 000229951900029

View details for PubMedID 15972418
Controversies in protocol selection in the Imaging of articular cartilage SEMINARS IN MUSCULOSKELETAL RADIOLOGY Gold, G. E., Hargreaves, B. A., Reeder, S. B., Vasanawala, S. S., Beaulieu, C. F. 2005; 9 (2): 161-172
Abstract

Magnetic resonance (MR) imaging, with its unique ability to noninvasively image and characterize soft tissue, has shown promise in assessment of cartilage. The development of new, fast imaging methods with high contrast will improve the MR evaluation of cartilage morphology. In addition to morphological MR imaging methods, MR imaging contrast mechanisms under development may reveal detailed information regarding the physiology of cartilage. However, many of these methods remain to be tested in the clinical setting. Protocol selection for cartilage imaging requires understanding of the patient population and the advantages and limitations of these techniques.

View details for Web of Science ID 000230039200008

View details for PubMedID 16044384
Rapid musculoskeletal MRI with phase-sensitive steady-state free precession: Comparison with routine knee MRI AMERICAN JOURNAL OF ROENTGENOLOGY Vasanawala, S. S., Hargreaves, B. A., Pauly, J. M., Nishimura, D. G., Beaulieu, C. F., Gold, G. E. 2005; 184 (5): 1450-1455
Abstract

The aim of this work was to show the potential utility of a novel rapid 3D fat-suppressed MRI method for joint imaging.Phase-sensitive steady-state free precession provides rapid 3D joint imaging with robust fat suppression and excellent cartilage delineation.

View details for Web of Science ID 000228875300013

View details for PubMedID 15855095
High hamstring tendinopathy in rummers - Meeting the challenges of diagnosis, treatment, and rehabiliatation PHYSICIAN AND SPORTSMEDICINE Fredericson, M., Moore, W., Guillet, M., Beaulieu, C. 2005; 33 (5): 32-43
Abstract

High hamstring tendinopathy is an uncommon overuse injury seen in running athletes. Patients typically report deep buttock or thigh pain. A detailed physical examination and, occasionally, imaging studies are necessary to confirm the diagnosis. Rehabilitation involves soft-tissue mobilization, frequent stretching, and progressive eccentric hamstring strengthening and core stabilization exercises. In recalcitrant cases, an ultrasound-guided corticosteroid injection into the tendon sheath can be helpful, and, occasionally, surgery may be necessary to release the scar tissue around the proximal hamstring muscles and the sciatic nerve.

View details for Web of Science ID 000229192000006

View details for PubMedID 20086362
Driven equilibrium magnetic resonance imaging of articular cartilage: Initial clinical experience JOURNAL OF MAGNETIC RESONANCE IMAGING Gold, G. E., Fuller, S. E., Hargreaves, B. A., Stevens, K. J., Beaulieu, C. F. 2005; 21 (4): 476-481
Abstract

To evaluate three-dimensional driven equilibrium Fourier transform (3D-DEFT) for image quality and detection of articular cartilage lesions in the knee.We imaged 104 consecutive patients with knee pain with 3D-DEFT and proton density (PD-FSE) and T2-weighted (T2-FSE) fast spin echo. Twenty-four went on to arthroscopy. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) efficiency were measured. Subjective image quality, fat suppression, and cartilage thickness visibility were assessed. Cartilage lesions on 3D-DEFT and T2-FSE were compared with findings outlined in operative reports.SNR efficiency was higher for 3D-DEFT and PD-FSE than for T2-FSE (P < 0.02). 3D-DEFT and PD-FSE showed superior cartilage thickness visibility compared with T2-FSE (P < 0.02). T2-FSE showed better fat suppression and fewer image artifacts than 3D-DEFT (P < 0.04). 3D-DEFT had similar sensitivity and similar specificity for cartilage lesions compared with PD-FSE and T2-FSE.3D-DEFT provides excellent synovial fluid-to-cartilage contrast while preserving signal from cartilage, giving this method a high cartilage SNR. 3D-DEFT shows the full cartilage thickness better than T2-FSE. T2-FSE had superior fat saturation and fewer artifacts than 3D-DEFT. Overall, 3D-DEFT requires further technical development, but is a promising method for imaging articular cartilage.

View details for DOI 10.1002/jhmi.20276

View details for PubMedID 15779031
Spectrum of MRI findings in femoral diaphyseal stress injuries 105th Annual Meeting of the American-Roentgen-Ray-Society Hwang, B. J., Fredericson, M., Chung, C. B., Beaulieu, C., Gold, G. AMER ROENTGEN RAY SOC. 2005: 107?
View details for Web of Science ID 000228717800443
The flexor hallucis longus: Tenographic technique and correlation of imaging findings with surgery in 39 ankles 105th Annual Meeting of the American-Roentgen-Ray-Society Na, J., Bergman, A. G., Oloff, L. M., Yoo, J., Beaulieu, C. F. AMER ROENTGEN RAY SOC. 2005: 111?12
View details for Web of Science ID 000228717800464
Musculoskeletal MRI at 3.0T: Initial clinical experience AMERICAN JOURNAL OF ROENTGENOLOGY Gold, G. E., Suh, B., Sawyer-Glover, A., Beaulieu, C. 2004; 183 (5): 1479-1486
View details for Web of Science ID 000224685700050

View details for PubMedID 15505324
Registration of central paths and colonic polyps between supine and prone scans in computed tomography colonography: Pilot study MEDICAL PHYSICS Ping, L., Napel, S., Acar, B., Paik, D. S., Jeffrey, R. B., Beaulieu, C. F. 2004; 31 (10): 2912-2923
Abstract

Computed tomography colonography (CTC) is a minimally invasive method that allows the evaluation of the colon wall from CT sections of the abdomen/pelvis. The primary goal of CTC is to detect colonic polyps, precursors to colorectal cancer. Because imperfect cleansing and distension can cause portions of the colon wall to be collapsed, covered with water, and/or covered with retained stool, patients are scanned in both prone and supine positions. We believe that both reading efficiency and computer aided detection (CAD) of CTC images can be improved by accurate registration of data from the supine and prone positions. We developed a two-stage approach that first registers the colonic central paths using a heuristic and automated algorithm and then matches polyps or polyp candidates (CAD hits) by a statistical approach. We evaluated the registration algorithm on 24 patient cases. After path registration, the mean misalignment distance between prone and supine identical anatomic landmarks was reduced from 47.08 to 12.66 mm, a 73% improvement. The polyp registration algorithm was specifically evaluated using eight patient cases for which radiologists identified polyps separately for both supine and prone data sets, and then manually registered corresponding pairs. The algorithm correctly matched 78% of these pairs without user input. The algorithm was also applied to the 30 highest-scoring CAD hits in the prone and supine scans and showed a success rate of 50% in automatically registering corresponding polyp pairs. Finally, we computed the average number of CAD hits that need to be manually compared in order to find the correct matches among the top 30 CAD hits. With polyp registration, the average number of comparisons was 1.78 per polyp, as opposed to 4.28 comparisons without polyp registration.

View details for DOI 10.1118/1.1796171

View details for Web of Science ID 000224743200025

View details for PubMedID 15543800
Automatic detection and classification of hypodense hepatic lesions on contrast-enhanced venous-phase CT MEDICAL PHYSICS Bilello, M., Gokturk, S. B., Desser, T., Napel, S., Jeffrey, R. B., Beaulieu, C. F. 2004; 31 (9): 2584-2593
Abstract

The objective of this work was to develop and validate algorithms for detection and classification of hypodense hepatic lesions, specifically cysts, hemangiomas, and metastases from CT scans in the portal venous phase of enhancement. Fifty-six CT sections from 51 patients were used as representative of common hypodense liver lesions, including 22 simple cysts, 11 hemangiomas, 22 metastases, and 1 image containing both a cyst and a hemangioma. The detection algorithm uses intensity-based histogram methods to find central lesions, followed by liver contour refinement to identify peripheral lesions. The classification algorithm operates on the focal lesions identified during detection, and includes shape-based segmentation, edge pixel weighting, and lesion texture filtering. Support vector machines are then used to perform a pair-wise lesion classification. For the detection algorithm, 80% lesion sensitivity was achieved at approximately 0.3 false positives (FP) per slice for central lesions, and 0.5 FP per slice for peripheral lesions, giving a total of 0.8 FP per section. For 90% sensitivity, the total number of FP rises to about 2.2 per section. The pair-wise classification yielded good discrimination between cysts and metastases (at 95% sensitivity for detection of metastases, only about 5% of cysts are incorrectly classified as metastases), perfect discrimination between hemangiomas and cysts, and was least accurate in discriminating between hemangiomas and metastases (at 90% sensitivity for detection of hemangiomas, about 28% of metastases were incorrectly classified as hemangiomas). Initial implementations of our algorithms are promising for automating liver lesion detection and classification.

View details for DOI 10.1118/1.1782674

View details for PubMedID 15487741
Musculoskeletal MRI at 3.0T: Relaxation times and image contrast AMERICAN JOURNAL OF ROENTGENOLOGY Gold, G. E., Han, E., Stainsby, J., Wright, G., Brittain, J., Beaulieu, C. 2004; 183 (2): 343-351
Abstract

The purpose of our study was to measure relaxation times in musculoskeletal tissues at 1.5 and 3.0 T to optimize musculoskeletal MRI methods at 3.0 T.In the knees of five healthy volunteers, we measured the T1 and T2 relaxation times of cartilage, synovial fluid, muscle, marrow, and fat at 1.5 and 3.0 T. The T1 relaxation times were measured using a spiral Look-Locker sequence with eight samples along the T1 recovery curve. The T2 relaxation times were measured using a spiral T2 preparation sequence with six echoes. Accuracy and repeatability of the T1 and T2 measurement sequences were verified in phantoms.T1 relaxation times in cartilage, muscle, synovial fluid, marrow, and subcutaneous fat at 3.0 T were consistently higher than those measured at 1.5 T. Measured T2 relaxation times were reduced at 3.0 T compared with 1.5 T. Relaxation time measurements in vivo were verified using calculated and measured signal-to-noise results. Relaxation times were used to develop a high-resolution protocol for T2-weighted imaging of the knee at 3.0 T.MRI at 3.0 T can improve resolution and speed in musculoskeletal imaging; however, interactions between field strength and relaxation times need to be considered for optimal image contrast and signal-to-noise ratio. Scanning can be performed in shorter times at 3.0 T using single-average acquisitions. Efficient higher-resolution imaging at 3.0 T can be done by increasing the TR to account for increased T1 relaxation times and acquiring thinner slices than at 1.5 T.

View details for Web of Science ID 000222895600028

View details for PubMedID 15269023
Surface normal overlap: A computer-aided detection algorithm, with application to colonic polyps and lung nodules in helical CT IEEE TRANSACTIONS ON MEDICAL IMAGING Paik, D. S., Beaulieu, C. F., Rubin, G. D., Acar, B., Jeffrey, R. B., Yee, J., Dey, J., Napel, S. 2004; 23 (6): 661-675
Abstract

We developed a novel computer-aided detection (CAD) algorithm called the surface normal overlap method that we applied to colonic polyp detection and lung nodule detection in helical computed tomography (CT) images. We demonstrate some of the theoretical aspects of this algorithm using a statistical shape model. The algorithm was then optimized on simulated CT data and evaluated using a per-lesion cross-validation on 8 CT colonography datasets and on 8 chest CT datasets. It is able to achieve 100% sensitivity for colonic polyps 10 mm and larger at 7.0 false positives (FPs)/dataset and 90% sensitivity for solid lung nodules 6 mm and larger at 5.6 FP/dataset.

View details for DOI 10.1109/TMI.2004.826362

View details for Web of Science ID 000221723600001

View details for PubMedID 15191141
Computed tomography colonography - Feasibility of computer-aided polyp detection in a "First reader" paradigm 88th Scientific Assembly and Annual Meeting of the Radiological-Society-of-North-America Mani, A., Napel, S., Paik, D. S., Jeffrey, R. B., Yee, J., Olcott, E. W., Prokesch, R., Davila, M., Schraedley-Desmond, P., Beaulieu, C. F. LIPPINCOTT WILLIAMS & WILKINS. 2004: 318?26
Abstract

: To determine the feasibility of a computer-aided detection (CAD) algorithm as the "first reader" in computed tomography colonography (CTC).: In phase 1 of a 2-part blind trial, we measured the performance of 3 radiologists reading 41 CTC studies without CAD. In phase 2, readers interpreted the same cases using a CAD list of 30 potential polyps.: Unassisted readers detected, on average, 63% of polyps > or =10 mm in diameter. Using CAD, the sensitivity was 74% (not statistically different). Per-patient analysis showed a trend toward increased sensitivity for polyps > or =10 mm in diameter, from 73% to 90% with CAD (not significant) without decreasing specificity. Computer-aided detection significantly decreased interobserver variability (P = 0.017). Average time to detection of the first polyp decreased significantly with CAD, whereas total reading case reading time was unchanged.: Computer-aided detection as a first reader in CTC was associated with similar per-polyp and per-patient detection sensitivity to unassisted reading. Computer-aided detection decreased interobserver variability and reduced the time required to detect the first polyp.

View details for Web of Science ID 000221234500003

View details for PubMedID 15100534
Advanced MR imaging of the shoulder: dedicated cartilage techniques. Magnetic resonance imaging clinics of North America Gold, G. E., Reeder, S. B., Beaulieu, C. F. 2004; 12 (1): 143-?
View details for PubMedID 15066598
Asymmetric closure of ischiopubic synchondrosis in pediatric patients: Correlation with foot dominance AMERICAN JOURNAL OF ROENTGENOLOGY Herneth, A. M., Philipp, M. O., Pretterklieber, M. L., Balassy, C., Winkelbauer, F. W., Beaulieu, C. F. 2004; 182 (2): 361-365
Abstract

The enlarged ischiopubic synchondrosis is a well-known anatomic structure; however, little is known about its physiology. In early childhood, enlargement of this synchondrosis occurs bilaterally, whereas before complete ossification, it is frequently found unilaterally. In most children, the unilateral enlarged ischiopubic synchondrosis is observed in the left hemipelvis, a finding that was hitherto unexplained. During common athletic activities, increased ground reaction forces are exerted on the weight-bearing nondominant limb, which in up to 87% of the general population is the left leg. The asymmetric exertion of these forces may explain the distinct closure sequence of this temporary joint. The purpose of this study was to correlate unilateral enlarged ischiopubic synchondrosis with foot dominance.The study cohort comprised 32 children who had undergone unenhanced radiography, CT, or MRI for reasons other than bone disorders and who presented with enlarged ischiopubic synchondroses. In these children, the distribution of enlarged ischiopubic synchondrosis and foot dominance were evaluated either retrospectively (n = 11) or prospectively (n = 21).In this cohort, 78% of patients were right-footed and 22% were left-footed. Nine of the 32 children presented with unilateral enlarged ischiopubic synchondrosis (left, seven [78%] of nine; right, two [22%] of nine). All children with enlarged left ischiopubic synchondrosis were right-footed, and all children with enlarged right ischiopubic synchondrosis were left-footed.Unilateral enlarged ischiopubic synchondrosis is closely correlated with foot dominance. The asymmetric ossification pattern of the ischiopubic synchondrosis indicates delayed ossification of this anatomic structure due to asymmetrically applied mechanical forces to the nondominant limb.

View details for Web of Science ID 000188590800024

View details for PubMedID 14736662
Knee cartilage volume with fluctuating equilibrium MRI 9th World Congress of the OsteoArthritis-Research-Society-International Gold, G. E., Hargreaves, B. A., Vasanawala, S. S., Webb, J., Shimakawa, A., Brittain, J. H., Pauly, J. M., Beaulieu, C. F. W B SAUNDERS CO LTD. 2004: S1?S1
View details for Web of Science ID 000225708200003
Radiology on handheld devices: Image display, manipulation, and PACS integration issues Annual Meeting of the Radiological-Society-of-North-America Raman, B., Raman, R., Raman, L., Beaulieu, C. F. RADIOLOGICAL SOC NORTH AMERICA. 2004: 299?310
Abstract

Handheld personal digital assistants (PDAs) have undergone continuous and substantial improvements in hardware and graphics capabilities, making them a compelling platform for novel developments in teleradiology. The latest PDAs have processor speeds of up to 400 MHz and storage capacities of up to 80 Gbytes with memory expansion methods. A Digital Imaging and Communications in Medicine (DICOM)-compliant, vendor-independent handheld image access system was developed in which a PDA server acts as the gateway between a picture archiving and communication system (PACS) and PDAs. The system is compatible with most currently available PDA models. It is capable of both wired and wireless transfer of images and includes custom PDA software and World Wide Web interfaces that implement a variety of basic image manipulation functions. Implementation of this system, which is currently undergoing debugging and beta testing, required optimization of the user interface to efficiently display images on smaller PDA screens. The PDA server manages user work lists and implements compression and security features to accelerate transfer speeds, protect patient information, and regulate access. Although some limitations remain, PDA-based teleradiology has the potential to increase the efficiency of the radiologic work flow, increasing productivity and improving communication with referring physicians and patients.

View details for Web of Science ID 000188058400026

View details for PubMedID 14730053
Magnetic resonance imaging in diagnosis of chronic posterolateral rotatory instability of the elbow. American journal of orthopedics (Belle Mead, N.J.) Grafe, M. W., McAdams, T. R., Beaulieu, C. F., Ladd, A. L. 2003; 32 (10): 501-503
Abstract

Posterolateral rotatory instability of the elbow can be difficult to diagnose and requires a high degree of clinical suspicion. Cases of chronic posterolateral rotatory instability (symptoms present more than 1 year) may be an even more perplexing subgroup. This is a case report of a patient with a 30-year history of intermittent elbow instability. Clinical examination was equivocal, and magnetic resonance imaging was unable to define any ligamentous injury around the elbow. Examination under anesthesia and surgical findings were consistent with complete disruption of the lateral ulnar collateral ligament. The 12-month follow-up after surgical reconstruction showed complete resolution of symptoms. Posterolateral rotatory instability is a diagnosis largely made by examination under anesthesia. A thorough history and a high clinical suspicion are necessary to support the physician's decision to place the patient under anesthesia. Confirmation of a chronic tear of the lateral ulnar collateral ligament of the elbow with magnetic resonance imaging can be difficult and sometimes misleading.

View details for PubMedID 14620091
CT colonography: Does improved z resolution help computer-aided polyp detection? MEDICAL PHYSICS Sundaram, P., Beaulieu, C. F., Paik, D. S., Schraedley-Desmond, P., Napel, S. 2003; 30 (10): 2663-2674
Abstract

Multislice helical CT offers several retrospective choices of longitudinal (z) resolution at a given detector collimation setting. We sought to determine the effect of z resolution on the performance of a computer-aided colonic polyp detector, since a human reader and a computer-aided polyp detector may have optimal performances at different z resolutions. We ran a computer-aided polyp detection algorithm on phantom data sets as well as data obtained from a single patient. All data were reconstructed at various slice thicknesses ranging from 1.25 to 10 mm. We studied the performance of the detector at various ranges of polyp sizes using free-response receiver-operating characteristic analyses. We also studied contrast-to-noise ratios (CNR) as a function of slice thickness and polyp size. For the phantom data, reducing the slice thickness from 5 to 1.25 mm improves sensitivity from 84.5% to 98.3% (all polyps), from 61.4% to 95.5% (polyps in the range [0, 5) mm) and from 97.7% to 100% (polyps in the range [5, 10) mm) at a false positive rate of 20 per data set. For polyps larger than 10 mm, there is no significant improvement in detection sensitivity when slice thickness is reduced. CNRs showed expected behavior with slice thickness and polyp size, but in all cases remained high (> 4). The results for the patient data followed similar patterns to that of the phantom case. Thus we conclude that for this detector, the optimal slice thickness is dependent upon the size of the smallest polyps to be detected. For detection of polyps 10 mm and larger, reconstruction of 5 mm sections may be sufficient. Further study is required to generalize these results to a broader population of patients scanned on different scanners.

View details for DOI 10.1118/1.1599985

View details for Web of Science ID 000185953700012

View details for PubMedID 14596303
Circular tomosynthesis: Potential in imaging of breast and upper cervical spine - Preliminary phantom and in vitro study 86th Scientific Assembly and Annual Meeting of the Radiological-Society-of-North-America (RSNA) Stevens, G. M., Birdwell, R. L., Beaulieu, C. F., Ikeda, D. M., Pelc, N. J. RADIOLOGICAL SOC NORTH AMERICA. 2003: 569?75
Abstract

Phantom and in vitro studies were performed to evaluate the potential application of digital circular tomosynthesis in imaging of the breast and upper cervical spine. A prototype volumetric x-ray system was used to image a mammographic phantom, a fresh mastectomy specimen, and a head phantom containing the upper cervical spine. Results show that breast tissue visualization is improved by the ability to produce sectional images that blur overlying structures and yield three-dimensional information about calcification clusters. In upper cervical spine imaging, digital circular tomosynthesis effectively blurs overlying jaw and skull structures so that C1 and C2 can be visualized in a standard anteroposterior view.

View details for DOI 10.1148/radiol.2282020295

View details for Web of Science ID 000184381100041

View details for PubMedID 12821770
The effect of pronation and supination on the minimally displaced scaphoid fracture CLINICAL ORTHOPAEDICS AND RELATED RESEARCH McAdams, T. R., Spisak, S., Beaulieu, C. F., Ladd, A. L. 2003: 255-259
Abstract

The amount of rotation that occurs at the scaphoid waist fracture site with pronation and supination of the forearm is studied in 10 upper extremities from cadavers. Two colinear metal markers were placed in the osteotomized scaphoid and a below-the-elbow cast was applied. Spiral volumetric computed tomography scanning of the scaphoid was done with multiplanar reformation to evaluate displacement of the metal markers. Four of the 10 specimens also were studied without any immobilization. The total magnitude of motion from pronation to supination averaged 0.2 mm in the specimens with a below-the-elbow thumb spica cast, and 2.4 mm in specimens without immobilization. The current study showed no significant rotation at the minimally displaced scaphoid waist fracture site during pronation and supination in a below-the-elbow cast. Furthermore, there is unacceptable rotation at the fracture site in the absence of a cast. Based on this study, a below-the-elbow thumb spica cast seems adequate for fracture immobilization; however, clinical correlation is needed.

View details for DOI 10.1097/01.blo.0000069886.31220.86

View details for PubMedID 12782882
Comparison of new sequences for high-resolution cartilage imaging MAGNETIC RESONANCE IN MEDICINE Hargreaves, B. A., Gold, G. E., Beaulieu, C. F., Vasanawala, S. S., Nishimura, D. G., Pauly, J. M. 2003; 49 (4): 700-709
Abstract

The high prevalence of osteoarthritis continues to demand improved accuracy in detecting cartilage injury and monitoring its response to different treatments. MRI is the most accurate noninvasive method of diagnosing cartilage lesions. However, MR imaging of cartilage is limited by scan time, signal-to-noise ratio (SNR), and image contrast. Recently, there has been renewed interest in SNR-efficient imaging sequences for imaging cartilage, including various forms of steady-state free-precession as well as driven-equilibrium imaging. This work compares several of these sequences with existing methods, both theoretically and in normal volunteers. Results show that the new steady-state methods increase SNR-efficiency by as much as 30% and improve cartilage-synovial fluid contrast by a factor of three. Additionally, these methods markedly decrease minimum scan times, while providing 3D coverage without the characteristic blurring seen in fast spin-echo images.

View details for DOI 10.1002/mrm.10424

View details for Web of Science ID 000182007200013

View details for PubMedID 12652541
Interactive and interventional sports medicine imaging. Topics in magnetic resonance imaging Beaulieu, C. F., Gold, G. E. 2003; 14 (2): 115-130
Abstract

The concepts and clinical potential of interactive magnetic resonance imaging (MRI) in which an examiner manipulates the joint of interest during MRI, and of interventional sports medicine imaging in which radiological guidance is used for targeted therapy of injuries and masses are described. As illustrated by a series of clinical cases, we believe that with further development, interactive MRI will play an important role in the comprehensive evaluation of patients with shoulder pain or dysfunction as well as other joint derangements. Interventional sports medicine takes advantage of the increasingly sophisticated diagnostic value of MRI and the radiologist's ability to use imaging to guide percutaneous therapy. We review our recent experience treating a wide variety of disorders such as cysts, hematomas, and inflammatory disorders, focusing on techniques utilizing ultrasound and MR guidance.

View details for PubMedID 12777885
Protocols in sports magnetic resonance imaging. Topics in magnetic resonance imaging Gold, G. E., Hargreaves, B. A., Beaulieu, C. F. 2003; 14 (1): 3-23
Abstract

Magnetic resonance imaging, with its multiplanar imaging capability and superior soft-tissue contrast, has become the preferred method for imaging sports-related injuries. Advances in gradient technology, receiver coils, and imaging software have allowed the imaging of the injured athlete to take place quickly and at high resolution. Understanding the tissues being imaged, the underlying anatomy, and the capabilities of today's scanners is crucial to the design of intelligent and efficient protocols.

View details for PubMedID 12606866
Sacral stress fractures - Tracking down nonspecific pain in distance runners PHYSICIAN AND SPORTSMEDICINE Fredericson, M., Salamancha, L., Beaulieu, C. 2003; 31 (2): 31-?
Abstract

Sacral stress fractures are an underrecognized cause of low-back and gluteal pain in distance runners. The combination of low bone density and increased activity blurs the boundary between fatigue and insufficiency fractures in many runners. MRI is the preferred radiologic technique because of its ability to localize the site of injury and rule out tumors, disk disease, or sacroiliitis. By identifying the condition early, clinicians contribute to a favorable outcome and help most athletes return to full activity in 12 to 14 weeks.

View details for Web of Science ID 000180861500007

View details for PubMedID 20086455
Local staging of pancreatic carcinoma with multi-detector row CT: Use of curved planar reformations initial experience RADIOLOGY Prokesch, R. W., Chow, L. C., Beaulieu, C. F., Nino-Murcia, M., Mindelzun, R. E., Barnmer, R., Huang, J., Jeffrey, R. B. 2002; 225 (3): 759-765
Abstract

To evaluate the utility of curved planar reformations compared with standard transverse images in the assessment of pancreatic tumors.Forty-three patients suspected of having pancreatic tumors underwent contrast material-enhanced biphasic multi-detector row computed tomography (CT). Curved planar reformations were generated along the pancreatic duct, common bile duct, and major mesenteric vessels. Three blinded independent readers assessed the curved planar reformations and transverse images separately for the presence of tumor, resectability, and vascular involvement. The results were compared with those of a consensus panel who evaluated the curved planar reformations and transverse images together along with clinical data and surgical findings.Of 43 patients, 20 had pancreatic malignancies as judged by the consensus panel and proven at biopsy and/or clinical follow-up. For tumor detection, transverse images and curved planar reformations had an average sensitivity of 95.0% and 98.4% (P >.05), respectively, and an average specificity of 90.9% and 91.3% (P >.05), respectively. For tumor resectability, transverse images and curved planar reformations had an average sensitivity of 85.7% and 71.4% (P >.05), respectively, and an average specificity of 85.2% and 84.3% (P >.05), respectively. Average interpretation time was 6.4 minutes with transverse images and 4.1 minutes with curved planar reformations.Curved planar reformations are equivalent to transverse images in the detection of pancreatic tumors and determination of surgical resectability.

View details for DOI 10.1148/radiol.2253010886

View details for Web of Science ID 000179420800020

View details for PubMedID 12461258
Edge displacement field-based classification for improved detection of polyps in CT colonography IEEE TRANSACTIONS ON MEDICAL IMAGING Acar, B., Beaulieu, C. F., Gokturk, S. B., Tomasi, C., Paik, D. S., Jeffrey, R. B., Yee, J., Napel, S. 2002; 21 (12): 1461-1467
Abstract

Colorectal cancer can easily be prevented provided that the precursors to tumors, small colonic polyps, are detected and removed. Currently, the only definitive examination of the colon is fiber-optic colonoscopy, which is invasive and expensive. Computed tomographic colonography (CTC) is potentially a less costly and less invasive alternative to FOC. It would be desirable to have computer-aided detection (CAD) algorithms to examine the large amount of data CTC provides. Most current CAD algorithms have high false positive rates at the required sensitivity levels. We developed and evaluated a postprocessing algorithm to decrease the false positive rate of such a CAD method without sacrificing sensitivity. Our method attempts to model the way a radiologist recognizes a polyp while scrolling a cross-sectional plane through three-dimensional computed tomography data by classification of the changes in the location of the edges in the two-dimensional plane. We performed a tenfold cross-validation study to assess its performance using sensitivity/specificity analysis on data from 48 patients. The mean specificity over all experiments increased from 0.19 (0.35) to 0.47 (0.56) for a sensitivity of 1.00 (0.95).

View details for DOI 10.1109/TMI.2002.806405

View details for Web of Science ID 000180871100003

View details for PubMedID 12588030
3D differential descriptors for improved computer-aided detection (CAD) of colonic polyps in computed tomography colonography (CTC) 88th Scientific Assembly and Annual Meeting of the Radiological-Society-of-North-America Acar, B., Beaulieu, C. F., Paik, D. S., Yee, J., Jeffrey, R. B., Napel, S. S. RADIOLOGICAL SOC NORTH AMERICA. 2002: 405?406
View details for Web of Science ID 000178825101150
CT colonography: Improved polyp detection sensitivity and efficiency with computer aided detection (CAD) 88th Scientific Assembly and Annual Meeting of the Radiological-Society-of-North-America Mani, A., Napel, S. S., Paik, D. S., Olcott, E. W., Yee, J., Beaulieu, C. F. RADIOLOGICAL SOC NORTH AMERICA. 2002: 304?304
View details for Web of Science ID 000178825100757
Isoattenuating pancreatic adenocarcinoma at multi-detector row CT: Secondary signs RADIOLOGY Prokesch, R. W., Chow, L. C., Beaulieu, C. F., Bammer, R., Jeffrey, R. B. 2002; 224 (3): 764-768
Abstract

To assess the frequency of isoattenuating pancreatic adenocarcinoma with multi-detector row computed tomography (CT) and determine whether there are specific secondary signs that aid in detection.Fifty-three patients with pancreatic adenocarcinoma underwent contrast material-enhanced biphasic multi-detector row CT with curved planar reformation. Tumors were initially deemed isoattenuating or hypoattenuating to normal pancreatic parenchyma on the basis of visual inspection, and the degree of attenuation was confirmed by calculating the mean attenuation differences between normal pancreatic parenchyma and tumor (tumor-pancreas contrast) during the pancreatic phase. Indirect signs of pancreatic tumor were tabulated in patients with an isoattenuating tumor.Of the 53 patients, six (11%) had isoattenuating tumors with a mean tumor-pancreas contrast of 9.25 HU +/- 11.3 during the pancreatic phase and 4.15 HU +/- 8.5 during the portal venous phase. The secondary signs of pancreatic tumor in these six patients included an interrupted pancreatic duct (n = 5), dilated biliary and pancreatic ducts (n = 1), atrophic distal pancreatic parenchyma (n = 3), and mass effect and/or convex contour abnormality (n = 3). The mean tumor-pancreas contrast for the remaining 47 patients was 74.76 HU +/- 35.61 during the pancreatic phase.With no visible tumor-pancreas contrast for isoattenuating tumors, indirect signs such as mass effect, atrophic distal parenchyma, and an interrupted duct sign are important indicators for the presence of tumor.

View details for DOI 10.1148/radiol.2243011284

View details for Web of Science ID 000177621700021

View details for PubMedID 12202711
Automated generation of curved planar reformations from volume data: Method and evaluation RADIOLOGY Raman, R., Napel, S., Beaulieu, C. F., Bain, E. S., Jeffrey, R. B., Rubin, G. D. 2002; 223 (1): 275-280
Abstract

The authors developed and evaluated a method to automatically create interactive vascular curved planar reformations with computed tomographic (CT) angiographic data. The method decreased user interaction time by 86%, from 15 to 2 minutes. Expert reviewers were asked to indicate their confidence in differentiating automatically created images from clinical-quality manually produced images. The area under the receiver operating characteristic curve was 0.45 (95% CI: 0.39, 0.51), and a test of equivalency indicated that reviewers could not distinguish between images. They also graded image quality as equivalent to that with manual methods and found fewer artifacts on automatically created images. Automatic methods rapidly produce curved planar reformations of equivalent quality with reduced time and effort.

View details for Web of Science ID 000174611900037

View details for PubMedID 11930078
Interventional musculoskeletal procedures performed by using MR imaging guidance with a vertically open MR unit: Assessment of techniques and applicability RADIOLOGY Genant, J. W., Vandevenne, J. E., Bergman, A. G., Beaulieu, C. F., Kee, S. T., Norbash, A. M., Lang, P. 2002; 223 (1): 127-136
Abstract

To evaluate the safety of and time required for a broad range of musculoskeletal interventional procedures performed by using magnetic resonance (MR) imaging guidance with a vertically open 0.5-T unit.Sixty-three MR imaging-guided procedures were performed. A vertically open MR unit equipped with in-room display monitors allowed interactive freehand MR guidance predominantly with fast spin-echo and gradient-echo sequences. Each procedure was classified in terms of the anatomic location, procedure type, and tissue type involved. The procedures were evaluated for success of needle placement, adequacy of tissue sampling, total procedural time, needle time, number of needle passes, and complications.Procedures consisted of tissue sampling with core-needle (n = 6) or fine-needle aspiration (n = 20) biopsy, corticosteroid or contrast agent injection (n = 19), joint cyst aspiration (n = 7), and drainage (n = 11). Successful needle placement was achieved in all 63 cases. Cytologic and histologic tissue samples were sufficient for pathologic diagnosis in 24 of 26 cases. In two cases, complications occurred: transient local bleeding and a brief vasovagal episode. The mean total procedural time was 64.8 minutes; the mean needle time, 26.2 minutes; and the mean number of needle passes per patient, 1.6.With use of a vertically open MR unit, MR-guided interventional procedures involving bone, soft tissue, intervertebral disks, and joints are safe and sufficiently rapid for use in clinical practice.

View details for DOI 10.1148/radiol.2231010900

View details for Web of Science ID 000174611900018

View details for PubMedID 11930057
Quantification of distention in CT colonography: Development and validation of three computer algorithms RADIOLOGY Hung, P. W., Paik, D. S., Napel, S., Yee, J., Jeffrey, R. B., Steinauer-Gebauer, A., Min, J., Jathavedam, A., Beaulieu, C. F. 2002; 222 (2): 543-554
Abstract

Three bowel distention-measuring algorithms for use at computed tomographic (CT) colonography were developed, validated in phantoms, and applied to a human CT colonographic data set. The three algorithms are the cross-sectional area method, the moving spheres method, and the segmental volume method. Each algorithm effectively quantified distention, but accuracy varied between methods. Clinical feasibility was demonstrated. Depending on the desired spatial resolution and accuracy, each algorithm can quantitatively depict colonic diameter in CT colonography.

View details for Web of Science ID 000173502500035

View details for PubMedID 11818626
Handheld access to radiology teaching files: An automated system for format conversion and content creation Medical Imaging 2002 Conference Raman, R., Raman, L., Raman, B., Gold, G., Beaulieu, C. F. SPIE-INT SOC OPTICAL ENGINEERING. 2002: 249?259
View details for Web of Science ID 000176733900029
Automated creation of radiology teaching modules: Demonstration of PACS integration and distribution Medical Imaging 2002 Conference Raman, B., Raman, R., Raman, L., Rubin, G. D., Beaulieu, C. F. SPIE-INT SOC OPTICAL ENGINEERING. 2002: 373?380
View details for Web of Science ID 000176734200046
A statistical 3-D pattern processing method for computer-aided detection of polyps in CT colonography IEEE TRANSACTIONS ON MEDICAL IMAGING Gokturk, S. B., Tomasi, C., Acar, B., Beaulieu, C. F., Paik, D. S., Jeffrey, R. B., Yee, J., Napel, S. 2001; 20 (12): 1251-1260
Abstract

Adenomatous polyps in the colon are believed to be the precursor to colorectal carcinoma, the second leading cause of cancer deaths in United States. In this paper, we propose a new method for computer-aided detection of polyps in computed tomography (CT) colonography (virtual colonoscopy), a technique in which polyps are imaged along the wall of the air-inflated, cleansed colon with X-ray CT. Initial work with computer aided detection has shown high sensitivity, but at a cost of too many false positives. We present a statistical approach that uses support vector machines to distinguish the differentiating characteristics of polyps and healthy tissue, and uses this information for the classification of the new cases. One of the main contributions of the paper is the new three-dimensional pattern processing approach, called random orthogonal shape sections method, which combines the information from many random images to generate reliable signatures of shape. The input to the proposed system is a collection of volume data from candidate polyps obtained by a high-sensitivity, low-specificity system that we developed previously. The results of our ten-fold cross-validation experiments show that, on the average, the system increases the specificity from 0.19 (0.35) to 0.69 (0.74) at a sensitivity level of 1.0 (0.95).

View details for Web of Science ID 000173296700006

View details for PubMedID 11811825
Future of MR imaging of articular cartilage. Seminars in musculoskeletal radiology Gold, G. E., Beaulieu, C. F. 2001; 5 (4): 313-327
Abstract

Osteoarthritis, based on either cartilage injury or degeneration, is a leading cause of disability in the United States. Over the last several decades, much progress has been made in understanding cartilage injury and repair. Magnetic resonance (MR) imaging, with its unique ability to noninvasively image and characterize soft tissue, has shown promise in assessment of cartilage integrity. In addition to standard MR imaging methods, MR imaging contrast mechanisms under development may reveal detailed information regarding the physiology and morphology of cartilage. MR imaging will play a crucial role in assessing the success or failure of therapies addressing cartilage injury and degeneration.

View details for PubMedID 11745048
Dynamic MR imaging and stress testing in glenohumeral instability: Comparison with normal shoulders and clinical/surgical findings JOURNAL OF MAGNETIC RESONANCE IMAGING Hodge, D. K., Beaulieu, C. F., Thabit, G. H., Gold, G. E., Bergman, A. G., Butts, R. K., Dillingham, M. F., Herfkens, R. J. 2001; 13 (5): 748-756
Abstract

Our objectives were to test the hypotheses that: 1) during shoulder motion, glenohumeral alignment differs between asymptomatic shoulders and those with symptomatic instability; 2) during magnetic resonance (MR)-monitored physical exam or stress testing, glenohumeral alignment differs between asymptomatic shoulders and those with instability; and 3) glenohumeral translation during MR stress testing correlates with findings of shoulder instability by clinical exam and exam under anesthesia (EUA). Using an open-configuration 0.5 T MR imaging (MRI) system, we studied symptomatic shoulders in 11 subjects and compared them to their contralateral asymptomatic shoulders. Each shoulder was studied during abduction/adduction and internal/external rotation to determine the humeral head position on the glenoid. An examiner also performed the MR stress test on each shoulder by applying manual force on the humeral head during imaging. All shoulders were assigned an instability grade from the MR stress test, and this grade was correlated with: 1) clinical exam grade assigned during preoperative assessment by an orthopedic surgeon and 2) intraoperative instability grade by EUA immediately preceding arthroscopy. With dynamic abduction and internal/external rotation, the humeral head remained centered on the glenoid in 9 of 11 shoulders, but in two subjects there were dramatic demonstrations of subluxation. With stress testing, a trend toward more joint laxity was demonstrated in symptomatic than in asymptomatic joints (P = 0.11). MR grading of instability correlated directly with clinical grading in six cases and underestimated the degree of instability relative to clinical exam in the other cases. MR instability grading systematically underestimated instability compared with EUA in 7 of the 10 cases that underwent surgical repair. We concluded that dynamic MR evaluation of glenohumeral alignment did not demonstrate abnormalities in symptomatic shoulders in 8 of 10 patients, whereas 2 patients showed dramatic findings of subluxation. Manual stress testing during dynamic MR examination showed a strong correlation with clinical instability grading. Dynamic shoulder MR examination during stress testing could, with further validation, become a useful adjunct to shoulder instability evaluations. J. Magn. Reson. Imaging 2001;13:748-756.

View details for Web of Science ID 000171296300012

View details for PubMedID 11329197
Volume rendering of tendon-bone relationships using unenhanced CT AMERICAN JOURNAL OF ROENTGENOLOGY Pelc, J. S., Beaulieu, C. F. 2001; 176 (4): 973-977
Abstract

Clinically, three-dimensional CT of the extremities is most often used to display bony anatomy. However, by combining unenhanced CT with volume-rendering computer graphics, visualization of relationships between bone and soft-tissue structures such as muscle tendon is also possible. The aims of this study were to quantify CT attenuation values of peripheral tendon, muscle, and bone on unenhanced CT and to develop custom opacity transforms on the basis of the attenuation measurements to effectively depict tendon-muscle-bone relationships.The mean attenuation of peripheral tendon ( approximately 100 H) is distinctly higher than that of muscle ( approximately 60 H) enabling high-quality volume rendering of muscle-tendon-bone relationships with unenhanced CT. High-frequency (bone) CT reconstruction algorithms commonly used for extremity CT produce approximately twofold higher image noise and inferior three-dimensional renderings compared with those based on less noisy standard or soft-tissue reconstruction algorithms. These concepts can be used to uniquely reveal tendon-muscle-bone relationships for clinical, scientific, and educational purposes.

View details for Web of Science ID 000167684000028

View details for PubMedID 11264092
Multidetector CT of the pancreas and bile duct system: value of curved planar reformations. AJR. American journal of roentgenology Nino-Murcia, M., Jeffrey, R. B., Beaulieu, C. F., Li, K. C., Rubin, G. D. 2001; 176 (3): 689-693
View details for PubMedID 11222206
Pictorial essay - Multidetector CT of the pancreas and bile duct system: Value of curved planar reformations AMERICAN JOURNAL OF ROENTGENOLOGY Nino-Murcia, M., Jeffrey, R. B., Beaulieu, C. F., Li, K. C., Rubin, G. D. 2001; 176 (3): 689-693
View details for Web of Science ID 000167118800021
Medial axis registration of supine and prone CT colonography data 23rd Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society Acar, B., Napel, S., Paik, D. S., Li, P., Yee, J., Jeffrey, R. B., Beaulieu, C. F. IEEE. 2001: 2433?2436
View details for Web of Science ID 000178871900663
Assessment of an optical flow field-based polyp detector for CT colonography 23rd Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society Acar, B., Beaulieu, C. F., Paik, D. S., Gokturk, S. B., Tomasi, C., Yee, J., Napel, S. IEEE. 2001: 2774?2777
View details for Web of Science ID 000178871900754
Medical image compression based on region of interest, with application to colon CT images 23rd Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society Gokturk, S. B., Tomasi, C., Girod, B., Beaulieu, C. IEEE. 2001: 2453?2456
View details for Web of Science ID 000178871900668
A new 3-D volume processing method for polyp detection 23rd Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society Gokturk, S. B., Tomasi, C., Acar, B., Paik, D., Beaulieu, C., Napel, S. IEEE. 2001: 2522?2525
View details for Web of Science ID 000178871900686
Automated polyp detector for CT colonography: Feasibility study RADIOLOGY Summers, R. M., Beaulieu, C. F., Pusanik, L. M., Malley, J. D., Jeffrey, R. B., Glazer, D. I., Napel, S. 2000; 216 (1): 284-290
Abstract

An abdominal computed tomographic scan was modified by inserting 10 simulated colonic polyps with use of methods that closely mimic the attenuation, noise, and polyp-colon wall interface of naturally occurring polyps. A shape-based polyp detector successfully located six of the 10 polyps. When settings that enhanced the edge profile of polyps were chosen, eight of 10 polyps were detected. There were no false-positive detections. Shape analysis is technically feasible and is a promising approach to automated polyp detection.

View details for Web of Science ID 000087829500042

View details for PubMedID 10887263
Stair-step artifacts with single versus multiple detector-row helical CT 85th Annual Meeting and Scientific Assembly of the Radiological-Society-of-North-America (RSNA) Fleischmann, D., Rubin, G. D., Paik, D. S., Yen, S. Y., Hilfiker, P. R., Beaulieu, C. F., Napel, S. RADIOLOGICAL SOC NORTH AMERICA. 2000: 185?96
Abstract

To compare the effects of acquisition parameters on the magnitude and appearance of artifacts between single and multiple detector-row helical computed tomography (CT).A cylindric (12.7 x 305.0-mm) acrylic rod inclined 45 degrees relative to the z axis was scanned at the isocenter and 100 mm from the isocenter with single detector-row (single-channel) helical CT (beam width, 1-10 mm; pitch, 1.0, 2.0, or 3.0) and multiple detector-row (four-channel) helical CT (detector width, 1. 25, 2.5, 3.75, and 5 mm; pitch, 0.75 or 1.5). The SD of radius measurements along the rod (SD(r)) was used to quantify artifacts in all 72 data sets and to analyze their frequency patterns. Volume-rendered images of the data sets were ranked by six independent and blinded readers; findings were correlated with acquisition parameters and SD(r) measurements.SD(r) was smaller in four- than in single-channel helical CT for any given table increment (TI). In single-channel helical CT, SD(r) increased linearly with beam width and geometrically with pitch. In four-channel helical CT, SD(r) measurements were directly proportional to the TI, regardless of the detector width and pitch combination used. Off-center object position on average increased SD(r) by a factor of 1.6 for single-channel helical CT and by a factor of 2.0 for four-channel helical CT. Subjective rankings of image quality correlated excellently with SD(r) (Spearman r = 0.94, P <.001).Artifacts are quantitatively and subjectively smaller with four- compared with single-channel helical CT for any given TI.

View details for Web of Science ID 000087829500026

View details for PubMedID 10887247
Focal liver lesions: Pattern-based classification scheme for enhancement at arterial phase CT RADIOLOGY Nino-Murcia, M., Olcott, E. W., Jeffrey, R. B., Lamm, R. L., Beaulieu, C. F., Jain, K. A. 2000; 215 (3): 746-751
Abstract

To present our early experience with a classification scheme for categorizing focal liver lesions on the basis of the enhancement patterns that they exhibit in the arterial phase of computed tomography (CT) and to determine whether particular enhancement patterns suggest particular diagnoses.The authors reviewed arterial phase CT images in 100 consecutive patients with focal liver lesions, excluding simple cysts. The enhancement pattern of the dominant or representative lesion in each patient was classified into one of five categories-homogeneous, abnormal internal vessels or variegated, peripheral puddles, complete ring, or incomplete ring-by three radiologists blinded to the proved diagnosis. Lesions without enhancement were recorded separately. Agreement was reached by consensus in all cases. Standards of reference included findings at histologic examination, correlative imaging, or clinical and imaging follow-up.Ninety-two percent of the 100 lesions demonstrated arterial phase enhancement. Patterns associated with positive predictive values of 82% or greater and specificity of 80% or greater included abnormal internal vessels or variegated (hepatocellular carcinoma), peripheral puddles (hemangioma), and complete ring (metastasis).The appearance of hepatic lesions in the arterial phase of enhancement has potential use in the determination of specific diagnoses. The classification scheme used in this study may be a useful tool for the interpretation of arterial phase CT studies.

View details for Web of Science ID 000087247000020

View details for PubMedID 10831693
Aortic aneurysmal disease: Assessment of stent-graft treatment - CT versus conventional angiography RADIOLOGY Armerding, M. D., Rubin, G. D., Beaulieu, C. F., Slonim, S. M., Olcott, E. W., Samuels, S. L., Jorgensen, M. J., Semba, C. P., Jeffrey, R. B., Dake, M. D. 2000; 215 (1): 138-146
Abstract

To compare computed tomographic (CT) angiography and conventional angiography for determining the success of endoluminal stent-graft treatment of aortic aneurysms.Forty patients underwent conventional angiography and CT angiography following treatment of aortoiliac aneurysms with endoluminal stent-grafts. Six additional sets of conventional angiographic-CT angiographic examinations were performed in five patients after placement of additional stent-grafts or coil embolization to treat perigraft leakage. Three faculty CT radiologists who were blinded to patient clinical data and outcome independently interpreted the CT angiograms, and three faculty angiographers, who were not involved in the stent-graft deployment, interpreted the conventional angiograms. Images were assessed for the presence of postdeployment complications. A reference standard was developed by experienced radiologists using all available images and clinical data. Sensitivities, specificities, and kappa values were calculated.Perigraft leakage was the most commonly identified complication. Twenty perigraft leaks were detected in the results of 46 examinations. Sensitivities and specificities for detecting perigraft leakage were 63% and 77% for conventional angiography and 92% and 90% for CT angiography, respectively. The kappa value was 0. 41 for conventional angiography and 0.81 for CT angiography.CT angiography is the preferred method for establishing the presence of perigraft leakage following treatment of aortoiliac aneurysms with stent-grafts.

View details for Web of Science ID 000086156700021

View details for PubMedID 10751479
Visualization modes for CT colonography using cylindrical and planar map projections JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Paik, D. S., Beaulieu, C. F., Jeffrey, R. B., Karadi, C. A., Napel, S. 2000; 24 (2): 179-188
Abstract

The purpose of this study was to demonstrate the limitations to the effectiveness of CT colonography, colloquially called virtual colonoscopy (VC), for detecting polyps in the colon and to describe a new technique, map projection CT colonography using Mercator projection and stereographic projection, that overcomes these limitations.In one experiment, data sets from nine patients undergoing CT colonography were analyzed to determine the percentage of the mucosal surface visible in various visualization modes as a function of field of view (FOV). In another experiment, 40 digitally synthesized polyps of various sizes (10, 7, 5, and 3.5 mm) were randomly inserted into four copies of one patient data set. Both Mercator and stereographic projections were used to visualize the surface of the colon of each data set. The sensitivity and positive predictive value (PPV) were calculated and compared with the results of an earlier study of visualization modes using the same CT colonography data.The percentage of mucosal surface visualized by VC increases with greater FOV but only approaches that of map projection VC (98.8%) at a distorting, very high FOV. For both readers and polyp sizes of > or =7 mm, sensitivity for Mercator projection (87.5%) and stereographic projection (82.5%) was significantly greater (p < 0.05) than for viewing axial slices (62.5%), and Mercator projection was significantly more sensitive than VC (67.5%). Mercator and stereographic projection had PPVs of 75.4 and 78.9%, respectively.The sensitivity of conventional CT colonography is limited by the percentage of the mucosal surface seen. Map projection CT colonography overcomes this problem and provides a more sensitive method with a high PPV for detecting polyps than other methods currently being investigated.

View details for Web of Science ID 000086026800001

View details for PubMedID 10752876
Bilateral stress fractures of the anterior part of the tibial cortex. A case report. journal of bone and joint surgery. American volume Brukner, P., Fanton, G., Bergman, A. G., Beaulieu, C., Matheson, G. O. 2000; 82 (2): 213-218
View details for PubMedID 10682730
Bilateral stress fractures of the anterior part of the tibial cortex - A case report JOURNAL OF BONE AND JOINT SURGERY-AMERICAN VOLUME Brukner, P., Fanton, G., Bergman, A. G., Beaulieu, C., Matheson, G. O. 2000; 82A (2): 213-218
View details for Web of Science ID 000085208600007
Dynamic evaluation of shoulder instability using open MR imaging 14th International Congress and Exhibition on Computer Assisted Radiology and Surgery (CARS 2000) Beaulieu, C. F., Dillingham, M. F., Hodge, D. K., Butts, K., Gold, G. E., Thabit, G. H., Ladd, A. L., Bergman, A. G. ELSEVIER SCIENCE BV. 2000: 309?314
View details for Web of Science ID 000165685600052
Glenohumeral relationships during physiologic shoulder motion and stress testing: Initial experience with open MR imaging and active imaging-plane registration RADIOLOGY Beaulieu, C. F., Hodge, D. K., Bergman, A. G., Butts, K., Daniel, B. L., Napper, C. L., Darrow, R. D., Dumoulin, C. L., Herfkens, R. J. 1999; 212 (3): 699-705
Abstract

To test the hypotheses that open dynamic magnetic resonance (MR) imaging can (a) be used to evaluate and define normal shoulder motion in active joint motion and muscle contraction and (b) be used in conjunction with physical examination.With an open-configuration, 0.5-T MR imaging system and active image-plane tracking, 10 shoulders were studied in five asymptomatic subjects to establish normal patterns of glenohumeral motion during abduction and adduction and internal and external rotation. Preliminary studies of physical examination during MR imaging, in which a physician examiner applied mechanical force to the humeral head, were also performed.During abduction and adduction and internal and external rotation maneuvers with active subjects muscle contraction, the humeral head remained precisely centered on the glenoid fossa in all asymptomatic subjects, which is in agreement with findings of previous radiographic studies. Application of force to the humeral head by an examiner was associated with as much as 6 mm of anterior translation and 13 mm of posterior translation.Dynamic MR imaging of the glenohumeral joint is possible over a wide range of physiologic motion in vertically open systems. Use of an MR tracking coil enabled accurate tracking of the anatomy of interest. These preliminary measurements of normal glenohumeral motion patterns begin to establish normal ranges of motion and constitute a necessary first step in characterizing pathologic motion in patients with common clinical problems such as instability and impingement.

View details for PubMedID 10478235
Display modes for CT colonography - Part I. Synthesis and insertion of polyps into patient CT data RADIOLOGY Karadi, C., Beaulieu, C. F., Jeffrey, R. B., Paik, D. S., Napel, S. 1999; 212 (1): 195-201
Abstract

To develop and validate a method for the insertion of digitally synthesized polyps into computed tomographic (CT) images of the human colon for use as ground truth for evaluation of virtual colonoscopy.Spiral CT simulator software was used to generate 10 synthetic polyps in various configurations. Additional software was developed to insert these polyps into volume CT scans. Ten polyps in eight patients were selected for comparison. Three radiologists evaluated whether two-dimensional (2D) CT images and three-dimensional (3D) volume-rendered CT images showed synthetic or real polyps.Edge-response profiles and noise of simulated polyps matched those of native polyps. Frequency distributions of reviewers' responses were not significantly different for synthetic versus real polyps in either 3D or 2D images. Responses were clustered around the response of "unsure" if lesions were real or synthetic. Receiver operating characteristic curves had areas of 0.54 (95% CI = 0.39, 0.68) for 3D and 0.39 (95% CI = 0.25, 0.53) for 2D images, which were not significantly different from random guessing (P = .70 and .28 for 3D and 2D images, respectively).Synthetic polyps were indistinguishable from real polyps. This method can be used to generate ground truth experimental data for comparison of CT colonographic display and detection methods.

View details for Web of Science ID 000081086900031

View details for PubMedID 10405742
Joint motion in an open MR unit using MR tracking JOURNAL OF MAGNETIC RESONANCE IMAGING Pearle, A. D., Daniel, B. L., Bergman, A. G., Beaulieu, C. F., Lang, P., Dumoulin, C. L., Darrow, R. D., Norbash, A. M., Napper, C. L., Hurtak, W., Butts, K. 1999; 10 (1): 8-14
Abstract

A system for active scan plane guidance during kinematic magnetic resonance (MR) examination of joint motion was developed utilizing an external tracking coil and MR tracking software. In a phantom study and during upright, weight-bearing, physiologic knee flexion, the external tracking coil maintained the scan plane through desired structures. Thus, MR tracking provides a robust method to guide the scan plane during MR imaging of active joint motion.

View details for Web of Science ID 000081199600002

View details for PubMedID 10398972
Display modes for CT colonography - Part II. Blinded comparison of axial CT and virtual endoscopic and panoramic endoscopic volume-rendered studies RADIOLOGY Beaulieu, C. F., Jeffrey, R. B., Karadi, C., Paik, D. S., Napel, S. 1999; 212 (1): 203-212
Abstract

To determine the sensitivity of radiologist observers for detecting colonic polyps by using three different data review (display) modes for computed tomographic (CT) colonography, or "virtual colonoscopy."CT colonographic data in a patient with a normal colon were used as base data for insertion of digitally synthesized polyps. Forty such polyps (3.5, 5, 7, and 10 mm in diameter) were randomly inserted in four copies of the base data. Axial CT studies, volume-rendered virtual endoscopic movies, and studies from a three-dimensional mode termed "panoramic endoscopy" were reviewed blindly and independently by two radiologists.Detection improved with increasing polyp size. Trends in sensitivity were dependent on whether all inserted lesions or only visible lesions were considered, because modes differed in how completely the colonic surface was depicted. For both reviewers and all polyps 7 mm or larger, panoramic endoscopy resulted in significantly greater sensitivity (90%) than did virtual endoscopy (68%, P = .014). For visible lesions only, the sensitivities were 85%, 81%, and 60% for one reader and 65%, 62%, and 28% for the other for virtual endoscopy, panoramic endoscopy, and axial CT, respectively. Three-dimensional displays were more sensitive than two-dimensional displays (P < .05).The sensitivity of panoramic endoscopy is higher than that of virtual endoscopy, because the former displays more of the colonic surface. Higher sensitivities for three-dimensional displays may justify the additional computation and review time.

View details for Web of Science ID 000081086900032

View details for PubMedID 10405743
New visualization techniques for virtual colonoscopy: Methods and evaluation 1st International Workshop on Computer-Aided Diagnosis Napel, S., Beaulieu, C. F., Paik, D. S., Karadi, C., Jeffrey, R. B. ELSEVIER SCIENCE BV. 1999: 463?468
View details for Web of Science ID 000084227800068
Magnetic resonance imaging of knee cartilage repair. Topics in magnetic resonance imaging Gold, G. E., Bergman, A. G., Pauly, J. M., Lang, P., Butts, R. K., Beaulieu, C. F., Hargreaves, B., Frank, L., Boutin, R. D., Macovski, A., Resnick, D. 1998; 9 (6): 377-392
Abstract

Cartilage injury resulting in osteoarthritis is a frequent cause of disability in young people. Osteoarthritis, based on either cartilage injury or degeneration, is a leading cause of disability in the United States. Over the last several decades, much progress has been made in understanding cartilage injury and repair. Magnetic resonance (MR) imaging, with its unique ability to noninvasively image and characterize soft tissue, has shown promise in assessment of cartilage integrity. In addition to standard MR imaging methods, MR imaging contrast mechanisms under development may reveal detailed information regarding the physiology and morphology of cartilage. MR imaging will play a crucial role in assessing the success or failure of therapies for cartilage injury and degeneration.

View details for PubMedID 9894740
Detection of colonic polyps in a phantom model: Implications for virtual colonoscopy data acquisition JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Beaulieu, C. F., Napel, S., Daniel, B. L., Ch'en, I. Y., Rubin, G. D., Johnstone, I. M., Jeffrey, R. B. 1998; 22 (4): 656-663
Abstract

Virtual colonoscopy is a new method of colon examination in which computer-aided 3D visualization of spiral CT simulates fiberoptic colonoscopy. We used a colon phantom containing various-sized spheres to determine the influence of CT acquisition parameters on lesion detectability and sizing.Spherical plastic beads with diameters of 2.5, 4, 6, 8 and 10 mm were randomly attached to the inner wall of segments of plastic tubing. Groups of three sealed tubes were scanned at 3/1, 3/2, 5/1 collimation (mm)/pitch settings in orientations perpendicular and parallel to the scanner gantry. For each acquisition, image sets were reconstructed at intervals from 0.5 to 5.0 mm. Two blinded reviewers assessed transverse cross-sections of the phantoms for bead detection, using source CT images for images for acquisitions obtained with the tubes oriented perpendicular to the gantry and using orthogonal reformatted images for scans oriented parallel to the gantry.Detection of beads of > or = 4 mm was 100% for both tube orientations and for all collimator/pitch settings and reconstruction intervals. For the 2.5 mm beads, detection decreased to 78-94% for 5 mm collimation/pitch 2 scans when the phantom sections were oriented parallel to the gantry (p = 0.01). Apparent elongation of beads in the slice direction occurred as the collimation and pitch increased. The majority of the elongation (approximately 75%) was attributable to changing the collimator from 3 to 5 mm, with the remainder of the elongation due to doubling the pitch from 1 to 2.CT scanning at 5 mm collimation and up to pitch 2 is adequate for detection of high contrast lesions as small as 4 mm in this model. However, lesion size and geometry are less accurately depicted than at narrower collimation and lower pitch settings.

View details for Web of Science ID 000074812400028

View details for PubMedID 9676463
Automated flight path planning for virtual endoscopy MEDICAL PHYSICS Paik, D. S., Beaulieu, C. F., Jeffrey, R. B., Rubin, G. D., Napel, S. 1998; 25 (5): 629-637
Abstract

In this paper, a novel technique for rapid and automatic computation of flight paths for guiding virtual endoscopic exploration of three-dimensional medical images is described. While manually planning flight paths is a tedious and time consuming task, our algorithm is automated and fast. Our method for positioning the virtual camera is based on the medial axis transform but is much more computationally efficient. By iteratively correcting a path toward the medial axis, the necessity of evaluating simple point criteria during morphological thinning is eliminated. The virtual camera is also oriented in a stable viewing direction, avoiding sudden twists and turns. We tested our algorithm on volumetric data sets of eight colons, one aorta and one bronchial tree. The algorithm computed the flight paths in several minutes per volume on an inexpensive workstation with minimal computation time added for multiple paths through branching structures (10%-13% per extra path). The results of our algorithm are smooth, centralized paths that aid in the task of navigation in virtual endoscopic exploration of three-dimensional medical images.

View details for Web of Science ID 000073650800004

View details for PubMedID 9608471
Anterior cruciate ligament injury: Fast spin-echo MR imaging with arthroscopic correlation in 217 examinations AMERICAN JOURNAL OF ROENTGENOLOGY Ha, T. P., Li, K. C., Beaulieu, C. F., Bergman, G., Ch'en, I. Y., Eller, D. J., Cheung, L. P., Herfkens, R. J. 1998; 170 (5): 1215-1219
Abstract

Our objective was to evaluate the accuracy of MR imaging strategy that uses primarily fast spin-echo sequences for the diagnosis of anterior cruciate ligament tears.The original clinical interpretations of MR images of 217 examinations of the knee joint were correlated with subsequent arthroscopic results. Each MR examination included a double-echo fast spin-echo sequence as the only imaging sequence in the sagittal plane. Subsequent discordant MR and arthroscopic examinations were then subjected to reanalysis by two observers who were unaware of arthroscopic results to determine if misinterpretations were observer or image dependent. Two hundred sixteen patients who underwent MR imaging for suspected internal derangement of the knee subsequently underwent arthroscopic surgery. Two patients had both knees evaluated. One patient was excluded because he was referred for evaluation for osteomyelitis, not internal derangement. This yielded a total number of 217 MR examinations for suspected internal derangement of the knee.For 56 arthroscopically proven tears, the sensitivity of MR imaging was 96%. The specificity was 98%, yielding an overall accuracy rate of 98%. The positive and negative predictive values were 95% and 99%, respectively. These values are within the ranges of previously reported MR imaging strategies using conventional spin-echo sequences.Fast spin-echo MR imaging of the knee can be an alternative to conventional spin-echo imaging for the detection of anterior cruciate ligament tears.

View details for Web of Science ID 000073257300014

View details for PubMedID 9574587
MR imaging of articular cartilage of the knee: New methods using ultrashort TEs AMERICAN JOURNAL OF ROENTGENOLOGY Gold, G. E., Thedens, D., Pauly, J. M., Fechner, K. P., Bergman, G., Beaulieu, C. F., Macovski, A. 1998; 170 (5): 1223-1226
View details for Web of Science ID 000073257300016

View details for PubMedID 9574589
MR arthrography of the wrist: Scanning-room injection of the radiocarpal joint based on clinical landmarks AMERICAN JOURNAL OF ROENTGENOLOGY Beaulieu, C. F., Ladd, A. L. 1998; 170 (3): 606-608
View details for Web of Science ID 000072129500013

View details for PubMedID 9490938
Sacral stress fractures in long-distance runners CLINICAL JOURNAL OF SPORT MEDICINE Eller, D. J., Katz, D. S., Bergman, A. G., Fredericson, M., Beaulieu, C. F. 1997; 7 (3): 222-225
View details for Web of Science ID A1997XP44000014

View details for PubMedID 9262893
Volume rendering of CT data: Applications to the genitourinary tract AMERICAN JOURNAL OF ROENTGENOLOGY Sommer, F. G., Olcott, E. W., Chen, I., Beaulieu, C. F. 1997; 168 (5): 1223-1226
View details for Web of Science ID A1997WV56800017

View details for PubMedID 9129415
Do arterial phase helical CT images improve detection or characterization of colorectal liver metastases? JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Chen, I. Y., Katz, D. S., Jeffrey, R. B., Daniel, B. L., Li, K. C., Beaulieu, C. F., Mindelzun, R. E., Yao, D., Olcott, E. W. 1997; 21 (3): 391-397
Abstract

Our goal was to determine if arterial phase images from dual phase helical CT improve either the detection or the characterization of hepatic metastases in patients with colorectal carcinoma. Sixty-two patients with known colorectal cancer underwent 65 dual phase helical CT examinations to evaluate for possible liver metastases. Three blinded reviewers independently evaluated the portal venous phase images alone to determine if hepatic metastases were present or absent. Arterial phase images were then analyzed to determine if they identified additional lesions or aided in characterizing small hepatic lesions. Scores of the two methods for diagnosing metastases were compared with the "gold standard" established by a consensus panel of three other radiologists who reviewed all images together with clinical, pathologic, and other imaging data. The addition of arterial phase imaging did not detect any new metastases. However, in 6 of the 64 technically adequate examinations, hepatic arterial phase images increased lesion conspicuity and significantly increased diagnostic confidence when compared with portal vein phase scans alone. In patients with colorectal cancer, the addition of arterial phase imaging does not increase sensitivity, but improves the specificity in diagnosing liver metastases in a small number of cases. Dual phase helical CT does not appear to be indicated in the evaluation of liver metastases from colorectal cancer.

View details for Web of Science ID A1997WV86400010

View details for PubMedID 9135646
The infraconal compartment: A multidirectional pathway for spread of disease between the extraperitoneal abdomen and pelvis JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Beaulieu, C. F., Mindelzun, R. E., Dolph, J., Jeffrey, R. B. 1997; 21 (2): 223-228
Abstract

The space below the kidneys where the anterior and posterior pararenal spaces converge has been defined only vaguley in the past. We describe observations on clinical CT cases and studies on cadavers that lead to a refinement in the terminology for this extraperitoneal compartment.Abdominal/pelvic CT scans from 18 patients and the scans of 2 cadavers injected in the femoral region with iodinated contrast material were reviewed concerning the location and distribution of fluid or gas collections relative to the renal fascial enclosure.Pathologic processes involving the anterior or posterior pararenal spaces in addition to the pelvic extraperitoneal spaces were always accompanied by collections in the space below the cone of renal fascia.The term infraconal compartment is a suggested term for the caudal continuation of the anterior and posterior pararenal spaces. This compartment serves as an important multidirectional pathway for the spread of disease between the extraperitoneal abdomen and the pelvis. Fluid collections within this compartment have a characteristic CT appearance.

View details for Web of Science ID A1997WM65500010

View details for PubMedID 9071290
Using biphasic CT to reveal gastrointestinal arteriovenous malformations AMERICAN JOURNAL OF ROENTGENOLOGY Mindelzun, R. E., Beaulieu, C. F. 1997; 168 (2): 437-438
View details for Web of Science ID A1997WD85600026

View details for PubMedID 9016222
Clinical image. Lipoblastoma of the thigh: MR appearance. Journal of computer assisted tomography Katz, D. S., Merchant, N., Beaulieu, C. F., Blankenberg, F. G. 1996; 20 (6): 1002-1003
View details for PubMedID 8933809
Lipoblastoma of the thigh: MR appearance JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY Katz, D. S., Merchant, N., Beaulieu, C. F., Blankenberg, F. G. 1996; 20 (6): 1002-1003
View details for Web of Science ID A1996VT47600027
Perspective volume rendering of CT and MR images: Applications for endoscopic imaging RADIOLOGY Rubin, G. D., Beaulieu, C. F., Argiro, V., Ringl, H., Norbash, A. M., Feller, J. F., Dake, M. D., Jeffrey, R. B., Napel, S. 1996; 199 (2): 321-330
Abstract

To use perspective volume rendering (PVR) of computed tomographic (CT) and magnetic resonance (MR) imaging data sets to simulate endoscopic views of human organ systems.Perspective views of helical CT and MR images were reconstructed from the data, and tissues were classified by assigning color and opacity based on their CT attenuation or MR signal intensity. "Flight paths" were constructed through anatomic regions by defining key views along a spline path. Twelve movies of the thoracic aorta (n=3), tracheobronchial tree (n=4), colon (n=3), paranasal sinuses (n=1), and shoulder joint (n=1) were generated to display images along the flight path. All abnormal results were confirmed at surgery.PVR fly-through enabled evaluation of the full range of tissue densities, signal intensities, and their three-dimensional spatial relationships.PVR is a novel way to present volumetric data and may enable noninvasive diagnostic endoscopy and provide an alternate method to analyze volumetric imaging data for primary diagnosis.

View details for Web of Science ID A1996UG01100006

View details for PubMedID 8668772
Assessment of several virtual endoscopy techniques using computed tomography and perspective volume rendering 4th International Conference on Visualization in Biomedical Computing (VBC 96) Shahidi, R., Argiro, V., Napel, S., Gray, L., McAdams, H. P., Rubin, G. D., Beaulieu, C. F., Jeffrey, R. B., Johnson, A. SPRINGER-VERLAG BERLIN. 1996: 521?528
View details for Web of Science ID A1996BH80E00064
Perspective volume rendering of cross-sectional images for simulated endoscopy and intra-parenchymal viewing Conference on Image Display Napel, S., Rubin, G. D., Beaulieu, C. F., Jeffrey, R. B., Argiro, V. SPIE - INT SOC OPTICAL ENGINEERING. 1996: 75?86
View details for Web of Science ID A1996BF60W00008

Christopher Beaulieu M.D., Ph.D.

Professor of Radiology (Musculoskeletal Imaging) and, by courtesy, of Orthopaedic Surgery at the Stanford University Medical Center

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