Bio

Clinical Focus


  • Diagnostic Radiology
  • Radiology

Academic Appointments


Administrative Appointments


  • Chief of Musculoskeletal Imaging, Stanford University Medical Center (2001 - Present)

Honors & Awards


  • Cum Laude Award (Co-recipient), SCBTMR (2007)
  • Cum Laude Award (Co-recipient), SCBTMR (2004)
  • Lauterbur Award (Co-recipient), SCBTMR (2003)
  • Lauterbur Award (Co-recipient), SCBTMR (2002)
  • Lauterbur Award (Co-recipient), SCBTMR (2001)
  • Fellow Election, Society of Computed Body Tomography and MRI (2000)
  • Hounsfield Award, SCBTMR (2000)
  • Cum Laude Award, SCBTMR (1999)
  • Cum Laude Award, SCBTMR (1998)
  • RSNA Scholars Award, Radiological Society of North America (1997)
  • Picker AUR Faculty Development Award, Association of University Radiologists (1996)
  • Cum Laude Award, Society of Computed Body Tomography and MRI (SCBTMR) (1996)
  • Chief Resident in Radiology, Duke University Medical Center (1993)
  • Doctor of Medicine with High Honors, University of Washington (1989)
  • Alpha Omega Alpha, University of Washington School of Medicine (1987)

Professional Education


  • Medical Education:University of Washington School of Medicine (1989) WA
  • Fellowship:Stanford University School of Medicine (1995) CA
  • Board Certification: Diagnostic Radiology, American Board of Radiology (1994)
  • Residency:Duke University Medical Center (1994) NC
  • Internship:Virginia Mason Medical Center (1990) WA
  • Fellow, Stanford University, Body Imaging (1995)
  • Resident, Duke University, Radiology (1994)
  • Ph.D., University of Washington, Biological Structure (1989)
  • M.D., University of Washington, Medicine (1989)
  • B.S., University of Washington, Chemistry (1982)

Research & Scholarship

Current Research and Scholarly Interests


Three dimensional computer graphics representation of, medical imaging data, including clinical applications of virtual, colonoscopy and arthroscopy; interactive MRI evaluation of joint, motion

Teaching

2013-14 Courses


Publications

Journal Articles


  • 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

  • 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

  • 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

  • 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 Web of Science ID 000282033600030

    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

  • 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 Web of Science ID 000274803800021

    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 Web of Science ID 000261139300036

    View details for PubMedID 19011194

  • 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 Web of Science ID 000258718100004

    View details for PubMedID 18516594

  • 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

  • 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 Web of Science ID 000248993500021

    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

  • 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

  • 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

  • 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

  • "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

  • 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 Web of Science ID 000239903400007

    View details for PubMedID 16846765

  • 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 Web of Science ID 000234868300008

    View details for PubMedID 16414467

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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 Web of Science ID 000228029900022

    View details for PubMedID 15779031

  • 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 Web of Science ID 000224117400027

    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 JOURNAL OF COMPUTER ASSISTED TOMOGRAPHY 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. 2004; 28 (3): 318-326

    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

  • Radiology on handheld devices: Image display, manipulation, and PACS integration issues RADIOGRAPHICS Raman, B., Raman, R., Raman, L., Beaulieu, C. F. 2004; 24 (1): 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

  • 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

  • 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

  • Circular tomosynthesis: Potential in imaging of breast and upper cervical spine - Preliminary phantom and in vitro study RADIOLOGY Stevens, G. M., Birdwell, R. L., Beaulieu, C. F., Ikeda, D. M., Pelc, N. J. 2003; 228 (2): 569-575

    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 Web of Science ID 000183379000030

    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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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
  • 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; 82A (2): 213-218
  • 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 Web of Science ID 000082196600016

    View details for PubMedID 10478235

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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

  • 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
  • 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

Conference Proceedings


  • Stair-step artifacts with single versus multiple detector-row helical CT Fleischmann, D., Rubin, G. D., Paik, D. S., Yen, S. Y., Hilfiker, P. R., Beaulieu, C. F., Napel, S. RADIOLOGICAL SOC NORTH AMERICA. 2000: 185-196

    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

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