Terry Desser

Abstract

Retained products of conception (RPOC) are a common and treatable complication after delivery or termination of pregnancy. The pathologic diagnosis of RPOC is made based on the presence of chorionic villi, which indicates persistent placental or trophoblastic tissue. In the setting of postpartum hemorrhage, however, distinguishing RPOC from bleeding related to normal postpartum lochia or uterine atony can be clinically challenging. Ultrasonographic (US) evaluation can be particularly helpful in these patients, and a thickened endometrial echo complex (EEC) or a discrete mass in the uterine cavity is a helpful gray-scale US finding that suggests RPOC. However, gray-scale US findings alone are inadequate for accurate diagnosis. Detection of vascularity in a thickened EEC or an endometrial mass at color or power Doppler US increases the positive predictive value for the diagnosis of RPOC. Computed tomography or magnetic resonance imaging may be helpful when US findings are equivocal and typically demonstrates an enhancing intracavitary mass in patients with RPOC. Diagnostic pitfalls are rare but may include highly vascular RPOC, which can be mistaken for a uterine arteriovenous malformation; true arteriovenous malformations of the uterus; invasive moles; blood clot; and subinvolution of the placental implantation site. © RSNA, 2013.

View details for DOI 10.1148/rg.333125177

View details for PubMedID 23674774

Abstract

Sonography is the modality of choice for imaging cervical lymph nodes in patients with papillary thyroid cancer, both before surgery and for postoperative surveillance. Sonography is also an invaluable tool to guide fine-needle aspiration of abnormal nodes. Microcalcifications, cystic changes, abnormal morphology, and disordered vascularity are features of metastatic nodal involvement with papillary thyroid carcinoma and should be sought during surveillance scans as well as in targeting for fine-needle aspiration.

View details for DOI 10.1097/RUQ.0b013e31827c7a9e

View details for Web of Science ID 000315449400004

View details for PubMedID 23358214

Abstract

Intraabdominal fat is a metabolically active tissue that may undergo necrosis through a number of mechanisms. Fat necrosis is a common finding at abdominal cross-sectional imaging, and it may cause abdominal pain, mimic findings of acute abdomen, or be asymptomatic and accompany other pathophysiologic processes. Common processes that are present in fat necrosis include torsion of an epiploic appendage, infarction of the greater omentum, and fat necrosis related to trauma or pancreatitis. In addition, other pathologic processes that involve fat may be visualized at computed tomography, including focal lipohypertrophy, pathologic fat paucity (lipodystrophies), and malignancies such as liposarcoma, which may mimic benign causes of fat stranding. Because fat necrosis and malignant processes such as liposarcoma and peritoneal carcinomatosis may mimic one another, knowledge of a patient's clinical history and prior imaging studies is essential for accurate diagnosis.

View details for DOI 10.1148/rg.317115046

View details for Web of Science ID 000297047000019

View details for PubMedID 22084185

Abstract

The objective of our study was to create a Bayesian network (BN) that incorporates a multitude of imaging features and patient demographic characteristics to guide radiologists in assessing the likelihood of malignancy in suspicious-appearing thyroid nodules.We built a BN to combine multiple indicators of the malignant potential of thyroid nodules including both imaging and demographic factors. The imaging features and conditional probabilities relating those features to diagnoses were compiled from an extensive literature review. To evaluate our network, we randomly selected 54 benign and 45 malignant nodules from 93 adult patients who underwent ultrasound-guided biopsy. The final diagnosis in each case was pathologically established. We compared the performance of our network with that of two radiologists who independently evaluated each case on a 5-point scale of suspicion for malignancy. Probability estimates of malignancy from the BN and radiologists were compared using receiver operating characteristic (ROC) analysis.The network performed comparably to the two expert radiologists. Using each radiologist's assessment of the imaging features as input to the network, the differences between the area under the ROC curve (A(z)) for the BN and for the radiologists were -0.03 (BN vs radiologist 1, 0.85 vs 0.88) and -0.01 (BN vs radiologist 2, 0.76 vs 0.77).We created a BN that incorporates a range of sonographic and demographic features and provides a probability about whether a thyroid nodule is benign or malignant. The BN distinguished between benign and malignant thyroid nodules as well as the expert radiologists did.

View details for DOI 10.2214/AJR.09.4037

View details for Web of Science ID 000289769000015

View details for PubMedID 21512051

Abstract

To enhance the educational experience among residents rotating through interventional radiology (IR) by encouraging ownership and responsibility.In May 2006, the authors implemented changes in resident education in IR that included increased clinical responsibilities, structured didactics, and greater hands-on experience, including call. Residents were assigned as first assistants, ownership of cases was encouraged, and assignment to a week on the consult service was instituted to help residents better understand all aspects of IR practice. Additional faculty recruitment and program expansion ensured the same high level of training for the fellowship program. Evaluations were reviewed every year (July 1, 2007-June 30, 2009) for hands-on training, daily teaching, didactic conferences, and overall effectiveness of the clinical service. A graduated scale of 1-5 was used.In 2009, 3 years after the curricular changes were made, the quality of hands-on training, daily case reviews and consults, didactics, and overall education had markedly improved with 89%, 71%, 65%, and 82% of the residents rating these respective aspects of the training as "above expectations" (4 on a scale of 5) or "superior" (5 on a scale of 5) compared with 77%, 23%, 20%, and 60% in 2005-2006. Three years after the changes, the impact of these changes on recruitment patterns also showed improvement, with 28.6% of the class of 2010 pursuing a fellowship in IR.Increasing resident ownership, responsibility, and hands-on experience improves resident education in IR, which, in turn, promotes interest in the field.

View details for DOI 10.1016/j.jvir.2010.07.009

View details for Web of Science ID 000284244200009

View details for PubMedID 20884234

Abstract

Ultrasonography is often the initial imaging study in patients who present with right upper quadrant abdominal complaints. However, due to its intrinsic technical limitations, ultrasonography generally has a lower sensitivity than contrast-enhanced computed tomography or magnetic resonance imaging in detecting hepatic lesions. In this review, we describe several subtle sonographic signs that suggest the presence of an otherwise inconspicuous focal liver lesion, including disease in the pleural space or the lung parenchyma, refractive edge shadows, distorted or absent venous landmarks, abnormal Doppler patterns, and venous thrombosis. When encountered, these features should trigger careful evaluation of the adjacent areas for abnormalities and may warrant further studies with computed tomography, magnetic resonance imaging, or positron emission tomography. We also summarize common sonographic findings of diffuse liver diseases, including fatty infiltration and cirrhosis.

View details for Web of Science ID 000297526800003

View details for PubMedID 20216191

Abstract

The objectives of our study were to describe a new CT sign of diaphragmatic injury, the "dangling diaphragm" sign, and assess its comparative utility relative to other signs in the diagnosis of diaphragmatic injury resulting from blunt trauma. CT scans of 16 blunt trauma patients (12 men and four women, mean age 36.6 years old) with surgically proven diaphragmatic injury and 32 blunt trauma patients (24 men and eight women; mean age 37.4 years old) without evidence of diaphragmatic injury at surgery were blindly reviewed by three board certified radiologists specializing in body imaging. Studies were evaluated for the presence of established signs of diaphragmatic injury, as well as the dangling diaphragm sign, in which the free edge of the torn hemidiaphragm curls inward from its normal course parallel to the body wall. The sensitivity and specificity of each sign were determined, as were the correlation between the signs and the interobserver agreement in evaluation of these findings. The radiologists' overall impression as to whether rupture was present was also recorded. In select cases, coronal and/or sagittal reformatted images were available, and they were reviewed following evaluation of the original axial images. Any change in interpretation due to these images was noted. The sensitivity of the radiologists' overall impression for detection of diaphragmatic injury was 77%, with 98% specificity. Individual signs of diaphragmatic injury had sensitivities ranging from 44% to 69%, with specificities of 98% to 100%. The dangling diaphragm sign had a sensitivity of 54% and a specificity of 98%, similar to the other signs. Multiple signs were present in most cases of diaphragmatic injury, and coronal and sagittal reformatted images had little impact. Diaphragmatic injury remains a challenging radiographic diagnosis. The dangling diaphragm is a conspicuous sign of diaphragmatic injury, and awareness of it may increase detection of diaphragmatic injury on CT studies.

View details for DOI 10.1007/s10140-009-0819-5

View details for PubMedID 19449046

Abstract

Hypervascular hepatocellular lesions include both benign and malignant etiologies. In the benign category, focal nodular hyperplasia and adenoma are typically hypervascular. In addition, some regenerative nodules in cirrhosis may be hypervascular. Malignant hypervascular primary hepatocellular lesions include hepatocellular carcinoma, fibrolamellar carcinoma, and peripheral cholangiocarcinoma. Vascular liver lesions often appear hypervascular because they tend to follow the enhancement of the blood pool; these include hemangiomas, arteriovenous malformations, angiosarcomas, and peliosis. While most gastrointestinal malignancies that metastasize to the liver will appear hypovascular on arterial and portal-venous phase imaging, certain cancers such as metastatic neuroendocrine tumors (including pancreatic neuroendocrine tumors, carcinoid, and gastrointestinal stromal tumors) tend to produce hypervascular metastases due to the greater recruitment of arterial blood supply. Finally, rare hepatic lesions such as glomus tumor and inflammatory pseudotumor may have a hypervascular appearance.

View details for DOI 10.1053/j.sult.2009.06.001

View details for Web of Science ID 000270442900003

View details for PubMedID 19842564

Abstract

Postpartum complications can be broadly divided into 4 categories: postpartum hemorrhage, obstetrical trauma, thromboembolic complications, and puerperal infections. Postpartum hemorrhage is most commonly caused by uterine atony, abnormal placentation, or genital tract trauma. Secondary causes of hemorrhage include retained products of conception and, rarely, subinvolution of the placental implantation site. Uterine dehiscence or rupture may be occult on ultrasound examination and may be better visualized on sagittal computed tomography or magnetic resonance imaging. Obstetric trauma during prolonged vaginal or cesarean delivery may lead to fistula formation, ureteral injury, or bowel injury. Later potential complications of cesarean delivery include cesarean delivery scar ectopic, endometrial implants in the cesarean scar, and placenta accreta. Thromboembolic complications can include pulmonary embolism and deep vein thrombosis as well as ovarian vein thrombosis, the latter of which can be difficult to clinically differentiate from appendicitis in the postpartum female.

View details for Web of Science ID 000208127100008

View details for PubMedID 19730078

Abstract

The authors report on the local control and toxicity of stereotactic body radiotherapy (SBRT) for patients with unresectable pancreatic adenocarcinoma.Seventy-seven patients with unresectable adenocarcinoma of the pancreas received 25 gray (Gy) in 1 fraction. Forty-five patients (58%) had locally advanced disease, 11 patients (14%) had medically inoperable disease, 15 patients (19%) had metastatic disease, and 6 patients (8%) had locally recurrent disease. Nine patients (12%) had received prior chemoradiotherapy. Sixteen patients (21%) received between 45 to 54 Gy of fractionated radiotherapy and SBRT. Various gemcitabine-based chemotherapy regimens were received by 74 patients (96%), but 3 patients (4%) did not receive chemotherapy until they had distant failure.The median follow-up was 6 months (range, 3-31 months) and, among surviving patients, it was 12 months (range, 3-31 months). The overall rates of freedom from local progression (FFLP) at 6 months and 12 months were 91% and 84%, respectively. The 6- and 12-month isolated local recurrence rates were 5% and 5%, respectively. There was no difference in the 12-month FFLP rate based on tumor location (head/uncinate, 91% vs body/tail, 86%; P = .52). The progression-free survival (PFS) rates at 6 months and 12 months were 26% and 9%, respectively. The PFS rate at 6 months was superior for patients who had nonmetastatic disease versus patients who had metastatic disease (28% vs 15%; P = .05). The overall survival (OS) rates at 6 months and 12 months from SBRT were 56% and 21%, respectively. Four patients (5%) experienced grade > or = 2 acute toxicity. Three patients (4%) experienced grade 2 late toxicity, and 7 patients (9%) experienced grade > or = 3 late toxicity. At 6 months and 12 months, the rates of grade > or = 2 late toxicity were 11% and 25%, respectively.SBRT for pancreatic adenocarcinoma was effective for local control with associated risk of toxicity and should be used with rigorous attention to quality assurance. Efforts to reduce complications are warranted. Distant metastases account for the vast majority of disease-related mortality.

View details for DOI 10.1002/cncr.24059

View details for Web of Science ID 000263003400025

View details for PubMedID 19117351

Abstract

It is challenging to distinguish benign from malignant thyroid nodules on high resolution ultrasound. Many ultrasound features have been studied individually as predictors for thyroid malignancy, none with a high degree of accuracy, and there is no consistent vocabulary used to describe the features. Our hypothesis is that a standard vocabulary will advance accuracy. We performed a systemic literature review and identified all the sonographic features that have been well studied in thyroid cancers. We built a controlled vocabulary for describing sonographic features and to enable us to unify data in the literature on the predictive power of each feature. We used this terminology to build a Bayesian network to predict thyroid malignancy. Our Bayesian network performed similar to or slightly better than experienced radiologists. Controlled terminology for describing thyroid radiology findings could be useful to characterize thyroid nodules and could enable decision support applications.

View details for PubMedID 21347173

Abstract

Hepatic infections include pyogenic and amebic abscesses and fungal and parasitic diseases. Entry of the infectious organisms into the liver can occur by hematogenous spread via the portal vein or hepatic artery, ascension of the infection from the biliary tract, or from trauma. Worldwide, liver abscess is most often caused by Entamoeba histolytica, but in the developed world, pyogenic liver abscess is more common. Fungal infection is most often seen in immunosuppressed chemotherapy patients, whereas parasitic infections are seen in patients with recent travel to endemic areas of Asia, Africa, and South America. Imaging, and in particular ultrasound, plays a crucial role in following patients from treatment to resolution of disease.We review the ultrasound and computed tomographic findings and the clinical features that are characteristic of hepatic pyogenic abscess, amebic abscess, fungal infection, and parasitic infection.

View details for DOI 10.1097/RUQ.0b013e31818e5981

View details for PubMedID 19060716

Abstract

Fractionated radiotherapy and chemotherapy for locally advanced pancreatic cancer achieves only modest local control. This prospective trial evaluated the efficacy of a single fraction of 25 Gy stereotactic body radiotherapy (SBRT) delivered between Cycle 1 and 2 of gemcitabine chemotherapy.A total of 16 patients with locally advanced, nonmetastatic, pancreatic adenocarcinoma received gemcitabine with SBRT delivered 2 weeks after completion of the first cycle. Gemcitabine was resumed 2 weeks after SBRT and was continued until progression or dose-limiting toxicity. The gross tumor volume, with a 2-3-mm margin, was treated in a single 25-Gy fraction by Cyberknife. Patients were evaluated at 4-6 weeks, 10-12 weeks, and every 3 months after SBRT.All 16 patients completed SBRT. A median of four cycles (range one to nine) of chemotherapy was delivered. Three patients (19%) developed local disease progression at 14, 16, and 21 months after SBRT. The median survival was 11.4 months, with 50% of patients alive at 1 year. Patients with normal carbohydrate antigen (CA)19-9 levels either at diagnosis or after Cyberknife SBRT had longer survival (p <0.01). Acute gastrointestinal toxicity was mild, with 2 cases of Grade 2 (13%) and 1 of Grade 3 (6%) toxicity. Late gastrointestinal toxicity was more common, with five ulcers (Grade 2), one duodenal stenosis (Grade 3), and one duodenal perforation (Grade 4). A trend toward increased duodenal volumes radiated was observed in those experiencing late effects (p = 0.13).SBRT with gemcitabine resulted in comparable survival to conventional chemoradiotherapy and good local control. However, the rate of duodenal ulcer development was significant.

View details for DOI 10.1016/j.ijrobp.2008.01.051

View details for Web of Science ID 000259894300008

View details for PubMedID 18395362

Abstract

Small bowel obstruction (SBO) is a common clinical problem, and clinical signs and symptoms often do not provide sufficient information for diagnosis or to guide management. During the past two decades, computed tomography has become a mainstay in the evaluation of patients with known or suspected small bowel obstruction. Computed tomography scans should be performed and interpreted with attention to establishing the diagnosis of small bowel obstruction, locating the transition point indicating the site of obstruction, and determining the cause of the obstruction. Complications that suggest the need for urgent surgical intervention, such as closed loop obstruction with superimposed ischemia and/or volvulus, should be sought in every case. Current generation multidetector row computed tomography scanners, with their isotropic resolution, now permit high-quality reformatted images to be obtained in multiple planes and facilitate identification of the transition point and other findings in SBO. Radiologists should be familiar with the myriad features of uncomplicated and complicated small bowel obstruction, which are reviewed in this article.

View details for DOI 10.1053/j.sult.2008.06.004

View details for Web of Science ID 000260064700003

View details for PubMedID 18853838

Abstract

Acute pelvic pain in the female patient can have myriad presentations and, depending on the diagnosis, profound consequences. In the pregnant patient with pelvic pain or bleeding, an ectopic pregnancy must be first excluded. Ultrasound is important in determining the size and location of the ectopic pregnancy, and presence of bleeding, which in turn helps guide treatment decisions. Subchorionic or subplacental bleeds in an intrauterine pregnancy may also present with vaginal bleeding with consequences dependent on gestational age and size of bleed. In the postpartum female suspected to have retained products of conception, sonographic findings may vary from a thickened endometrial stripe to an echogenic mass with associated marked vascularity, often mimicking an arterial-venous malformation. In the nonpregnant patient, early diagnosis and treatment of ovarian torsion can preserve ovarian function. Other causes of peritoneal irritation may also cause acute pelvic pain including a ruptured hemorrhagic cyst or ruptured endometrioma. When pelvic inflammatory disease is suspected, imaging is used to evaluate for serious associated complications including the presence of a tuboovarian abscess or peritonitis. While leiomyomas of the uterus are largely asymptomatic, a leiomyoma that undergoes necrosis, torsion or prolapse through the cervix may be associated with acute severe pain or bleeding. The imaging features of these and other important clinical entities in the female pelvis will be presented.

View details for DOI 10.1053/j.sult.2008.06.006

View details for Web of Science ID 000260064700006

View details for PubMedID 18853841

Abstract

Thyroid nodules can be detected in 4% to 8% of the adult population by palpation, but in 40% to 50% of the population by ultrasound. The overwhelming majority of these represent benign hyperplastic nodules or adenomas. Approximately 5% of nodules are malignant, with papillary carcinoma representing approximately 75% to 80% of primary thyroid malignancies. Although many sonographic features have been studied as a means of distinguishing benign from malignant nodules, ultrasound-guided fine-needle aspiration with cytologic evaluation remains a mainstay in the management of palpable and incidentally detected nodules. This article reviews the current techniques for sonographic evaluation of the thyroid and the imaging features of the various types of thyroid nodules.

View details for DOI 10.1016/j.nic.2008.03.005

View details for Web of Science ID 000258670800004

View details for PubMedID 18656028

Abstract

Much of the information needed for radiology teaching and research is not in the picture archiving and communication system but distributed in hospital information systems throughout the medical enterprise. Our objective is to describe the design, methodology, and implementation of a data warehouse to integrate and make accessible the types of medical data pertinent to radiology research and teaching, and to encourage implementation of similar approaches throughout the radiologic community.We identified desiderata of radiology data warehouses and designed and implemented a prototype system (RadBank) to meet these needs. RadBank was built with open-source software tools on a Linux platform with a relational database. We created a text report parsing module that recognizes the structure of radiology reports and makes individual sections available for indexing and search. A database schema was designed to link radiology and pathology reports and to enable users to retrieve cases using flexible queries.Our system contains more than 2 million radiology and pathology reports, and allows full text search by patient history, findings, and diagnosis by radiology and pathology. RadBank has helped radiologists at our institution find teaching cases and identify research cohorts.Data warehouses can provide radiologists access to important clinical information contained in radiology and pathology reports, and supplement the image information in picture archiving and communication system workstations. We believe that data warehouses similar to our system can be implemented in other radiology departments within a reasonable budget to make their vast radiologic-pathologic case material accessible for education and research.

View details for DOI 10.1016/j.jacr.2007.09.004

View details for PubMedID 18312970

Abstract

Thyroid nodules are a common, yet challenging clinical problem. The vast majority of these nodules are benign; however, deciding which nodule should undergo biopsy is difficult because the imaging appearance of benign and malignant thyroid nodules overlap. High resolution ultrasound is the primary imaging modality for evaluating thyroid nodules. Many sonographic features have been studied individually as predictors for thyroid malignancy. There has been little work to create predictive models that combine multiple predictors, both imaging features and demographic factors. We have created a Bayesian classifier to predict whether a thyroid nodule is benign or malignant using sonographic and demographic findings. Our classifier performed similar to or slightly better than experienced radiologists when evaluated using 41 thyroid nodules with known pathologic diagnosis. This classifier could be helpful in providing practitioners an objective basis for deciding whether to biopsy suspicious thyroid nodules.

View details for PubMedID 18999209

Abstract

Simulation-based training methods have been widely adopted in hazardous professions such as aviation, nuclear power, and the military. Their use in medicine has been accelerating lately, fueled by the public's concerns over medical errors as well as new Accreditation Council for Graduate Medical Education requirements for outcome-based and proficiency-based assessment methods. This article reviews the rationale for simulator-based training, types of simulators, their historical development and validity testing, and some results to date in laparoscopic surgery and endoscopic procedures. A number of companies have developed endovascular simulators for interventional radiologic procedures; although they cannot as yet replicate the experience of performing cases in real patients, they promise to play an increasingly important role in procedural training in the future.

View details for PubMedID 17964504

Abstract

Our purpose was to correlate the imaging findings of small cystic pancreatic lesions to the incidence of growth on follow-up imaging and their pathologic diagnoses.CT images for 159 patients with cystic pancreatic lesions were retrospectively evaluated and lesions were assessed for size, number, connection to the main pancreatic duct (MPD), MPD dilatation, and any presence of loculation, wall irregularity, thick septations, or solid components. A total of 86 patients had follow-up imaging with time periods of less than 6 months (n = 21), 6-12 months (n = 22), 1-2 years (n = 14), and greater than 2 years (n = 29). Lesion histology was available in 20 patients.Lesions with pathologic correlation proved to be: side branch intraductal papillary mucinous neoplasm or tumor (IPMT) (n = 5), combined type IPMT (n = 4), nonmucinous cyst (n = 4), chronic pancreatitis (n = 2), and reactive atypia with nonmucinous fluid (n = 1), combined type IMPT with foci of adenocarcinoma (n = 1), mucinous adenocarcinoma (n = 2), and nonmucinous adenocarcinoma (n = 1). Lesions with solid components were significantly more likely to grow and be malignant (P < 0.05). The presence of MPD dilatation was more common in patients with combined type IPMTs or malignancies. No other factors were predictive of malignancy.Solid components are predictive of malignancy, and MPD dilatation should prompt consideration of surgery. Other cystic lesions can be followed.

View details for DOI 10.1007/s00261-006-9080-5

View details for Web of Science ID 000246405800020

View details for PubMedID 16944031

Abstract

Lesions in the spleen may be encountered in a variety of clinical settings ranging from asymptomatic patients to patients who are critically ill. Etiologies for multifocal splenic lesions include infectious and inflammatory processes, primary vascular and lymphoid neoplasms, metastatic disease, vascular processes, and systemic diseases. There is often overlap in the imaging appearance alone, so the clinical setting is very helpful in differential diagnosis. In the immunocompromised patient, multiple small splenic lesions usually represent disseminated fungal disease and microabscesses. The spleen is a relatively rare site for metastatic disease; patients with metastatic lesions in the spleen usually have disease in other sites as well. Breast, lung, ovary, melanoma, and colon cancer are common primary tumors that metastasize to the spleen. Vascular neoplasms of the spleen represent the majority of the nonhematologic/nonlymphoid neoplasms and commonly produce multifocal lesions. Splenic infarcts may be seen with localized processes such as portal hypertension or pancreatitis, or may arise from an embolic source. Radiologists should be aware of the spectrum of processes that may involve the spleen and the clinical context in which they occur.

View details for DOI 10.1053/j.sult.2006.06.004

View details for Web of Science ID 000241312600004

View details for PubMedID 17048454

Abstract

Our objective was to illustrate the benefits of obtaining delayed CT images.There are several clinical scenarios in which delayed CT images may improve diagnostic specificity.

View details for DOI 10.2214/AJR.05.0148

View details for Web of Science ID 000238659600027

View details for PubMedID 16794170

Abstract

To promote active learning in an introductory Radiologic Anatomy course through the use of computer-based exercises.DICOM datasets from our hospital PACS system were transferred to a networked cluster of desktop computers in a medical school classroom. Medical students in the Radiologic Anatomy course were divided into four small groups and assigned to work on a clinical case for 45 minutes. The groups used iPACS viewer software, a free DICOM viewer, to view images and annotate anatomic structures. The classroom instructor monitored and displayed each group's work sequentially on the master screen by running SynchronEyes, a software tool for controlling PC desktops remotely.Students were able to execute the assigned tasks using the iPACS software with minimal oversight or instruction. Course instructors displayed each group's work on the main display screen of the classroom as the students presented the rationale for their decisions. The interactive component of the course received high ratings from the students and overall course ratings were higher than in prior years when the course was given solely in lecture format.DICOM viewing software is an excellent tool for enabling students to learn radiologic anatomy from real-life clinical datasets. Interactive exercises performed in groups can be powerful tools for stimulating students to learn radiologic anatomy.

View details for PubMedID 16554232

Abstract

Diagnostic ultrasound examinations may be performed after-hours by physicians if technologists are not available or cases are complex. Our experience suggested there is wide variability in how ultrasound coverage is provided after-hours, which motivated us to conduct a formal survey of teaching programs around the country.Four hundred five members of the Association of Program Directors in Radiology were contacted by e-mail and sent a link to a five-part questionnaire posted on the Web. Respondents were asked whether ultrasound cases after-hours are performed in their institutions by radiology residents, technologists on the premises after-hours, technologists on-call, or some combination. Data on the type of program, number of beds in the primary hospital, number of residents in the program, and geographic location of the program were recorded. Responses were automatically written to a data file stored on a Web server and the imported into an Excel spreadsheet for data analysis. A chi(2) analysis was performed to assess associations among the variables and statistical significance.A total of 79 programs responded to the survey. Of those, 32% provided coverage with ultrasound technologists on call, 24% by ultrasound technologists on the premises, 13% provided combination coverage, and 10% provided coverage solely with residents on call. There was no association among number of residents in the program, location of the program, or type of program (university, community, or affiliated) and type of coverage provided.There is wide variability in methods for providing coverage of after-hours ultrasound cases. However, on-site or on-call coverage of emergency cases by technologists did not appear to depend significantly on program location, program type, or program size.

View details for DOI 10.1016/j.acra.2005.09.091

View details for Web of Science ID 000235107800016

View details for PubMedID 16428062

Abstract

Pancreas cancer is the fourth leading cancer killer in adults. Cure of pancreas cancer is dependent on the complete surgical removal of localized tumor. A complete surgical resection is dependent on accurate preoperative and intra-operative imaging of tumor and its relationship to vital structures. Imaging of pancreatic tumors preoperatively and intra-operatively is achieved by pancreatic protocol computed tomography (CT), endoscopic ultrasound (EUS), laparoscopic ultrasound (LUS), and intra-operative ultrasound (IOUS). Multi-detector CT with three-dimensional (3-D) reconstruction of images is the most useful preoperative modality to assess resectability. It has a sensitivity and specificity of 90 and 99%, respectively. It is not observer dependent. The images predict operative findings. EUS and LUS have sensitivities of 77 and 78%, respectively. They both have a very high specificity. Further, EUS has the ability to biopsy tumor and obtain a definitive tissue diagnosis. IOUS is a very sensitive (93%) method to assess tumor resectability during surgery. It adds little time and no morbidity to the operation. It greatly facilitates the intra-operative decision-making. In reality, each of these methods adds some information to help in determining the extent of tumor and the surgeon's ability to remove it. We rely on pancreatic protocol CT with 3-D reconstruction and either EUS or IOUS depending on the tumor location and operability of the tumor and patient. With these modern imaging modalities, it is now possible to avoid major operations that only determine an inoperable tumor. With proper preoperative selection, surgery is able to remove tumor in the majority of patients.

View details for DOI 10.1016/j.suronc.2005.07.001

View details for Web of Science ID 000231899500005

View details for PubMedID 16125619

Abstract

The purpose of this study was to determine whether queueing theory would allow prediction of optimal number of schedule slots to be reserved for urgent computed tomography (CT) and ultrasonography (US). Institutional review board approval was obtained; informed consent was exempted. Emergency studies were modeled as a Poisson process; slots were reserved such that rate of rescheduling of routine studies to accommodate emergencies was predicted to be below a certain level. Model was tested with 3 years of emergency US and CT requests. US and CT requests showed Poisson distribution. US rescheduling was near that predicted. CT rescheduling exceeded that predicted, which reflected increasing CT use. By using more recent CT data for prediction, a more concordant rescheduling rate resulted.

View details for DOI 10.1148/radiol.2351040289

View details for Web of Science ID 000227952600036

View details for PubMedID 15716391

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

View details for Web of Science ID 000222163900059

View details for PubMedID 15208153

View details for Web of Science ID 000221555900028

View details for PubMedID 15149993

Abstract

To describe 2 cases of abdominal tuberculosis in which sonographic evaluation of mesenteric lymphadenopathy showed increased through-transmission suggestive of caseating necrosis.Two patients with abdominal pain and other symptoms (including fever, diarrhea, and weight loss) underwent abdominal sonography with a 6-MHz curved array transducer. One patient also underwent sonographically guided fine-needle aspiration of multiple lymph nodes, and the other underwent computed tomography, colonoscopy, and colon biopsy.In both patients, sonography showed multiple rounded hypoechoic lesions with increased ultrasound through-transmission suggestive of necrotic lymphadenopathy. No color flow was shown. In 1 case, the posterior acoustic enhancement was accentuated in the harmonic imaging mode. In the other case, the lesions shown on sonography corresponded to computed tomographic findings of low-density lymph nodes. Results of fine-needle aspiration and colon biopsy were positive for tuberculosis.Posterior acoustic enhancement in abdominal lymphadenopathy can suggest the diagnosis of tuberculous lymphadenitis. Detection of this finding is facilitated by scanning in the harmonic mode. Necrotic nodes will lack color flow and can be distinguished from lymphadenopathy of other causes. Sonography can also be used for fine-needle aspiration of necrotic nodes to yield a definitive diagnosis.

View details for Web of Science ID 000221973600013

View details for PubMedID 15244308

Abstract

To determine the relative frequency of various sonographic findings in papillary carcinoma of the thyroid.We retrospectively analyzed the sonographic features in 55 patients with proven papillary carcinoma of the thyroid. Sonographic features analyzed were echo texture, cystic change, margin, contour, presence of a peripheral halo, vascularity, and calcification pattern. Features were classified as common (> or = 35% of cases) or uncommon (< 10% of cases). Combinations of features were also analyzed.Common sonographic features of papillary carcinoma included hypoechoic texture (86%), microcalcifications (42%) or no calcifications (47%), well-defined margins (47%), and intrinsic hypervascularity (69%). Uncommon features included hyperechoic or mixed echo texture, cystic elements, irregular margins, hypovascularity, and coarse or peripheral calcifications. Of the 29 lesions that had calcifications, 20 (69%) had microcalcifications; 5 (17%) had coarse calcifications; and 1 had peripheral calcifications. In total, 54% of cases had at least 1 uncommon feature, and 11% had 2 or more uncommon features. Cystic carcinomas were rare and accounted for only 6% of lesions; all had hypervascular solid components. No carcinomas in our series were completely avascular.There is a broad spectrum of sonographic findings in papillary carcinoma of the thyroid. Half of the lesions in this series had at least 1 uncommon sonographic feature.

View details for Web of Science ID 000185658300011

View details for PubMedID 14606565

View details for Web of Science ID 000183149200015

View details for PubMedID 12760925

Abstract

Fallopian tube carcinoma is an unusual gynecologic malignancy that is rarely diagnosed preoperatively. We report a case of fallopian tube carcinoma occurring in a patient who had undergone a hysterectomy many years previously, in whom findings on computed tomography and ultrasound were highly suggestive of the diagnosis.

View details for Web of Science ID 000183746200011

View details for PubMedID 12794600

Abstract

Gallbladder injuries after blunt abdominal trauma are rare and often follow a vague and insidious clinical course. Consequently, gallbladder injuries commonly go undiagnosed until exploratory laparotomy. Early diagnosis is essential, because trauma to the gallbladder is typically treated surgically, and delay in treatment can result in considerable mortality and morbidity. With sonography emerging as a first-line modality for evaluation of intra-abdominal trauma, sonographers may wish to become more familiar with the appearance of gallbladder injury on sonography to facilitate earlier diagnosis and to improve treatment and prognosis. We report a case of gallbladder perforation after blunt abdominal trauma diagnosed on the basis of computed tomography (CT) and sonography.

View details for Web of Science ID 000178888200011

View details for PubMedID 12418769

Abstract

To review the sonographic features and focused sonographic scanning techniques that may assist in the preoperative localization of parathyroid adenomas in patients with primary hyperparathyroidism.The sonographic findings were reviewed in 54 of 58 consecutive patients with pathologically proven parathyroid adenomas. A systematic scanning approach including real-time gray scale, color and power Doppler, and graded compression gray scale imaging was used in all patients.Fifty-four (93%) of 58 proven adenomas were correctly identified by sonography. Gray scale imaging alone was sufficient for identifying 26 (100%) of 26 large (> or =1-cm) and 3 (11%) of 25 small (<1-cm) parathyroid adenomas. However, for 25 (89%) of 28 small adenomas, a combination of color and power Doppler and graded compression real-time gray scale imaging was required for sonographic localization and identification.Knowledge of typical locations and characteristic imaging features, as well as a systematic scanning approach, can result in accurate preoperative sonographic localization of parathyroid adenomas.

View details for Web of Science ID 000175342900009

View details for PubMedID 12008817

Abstract

Tissue harmonic imaging (THI) is a new gray-scale sonographic technique that improves image clarity. Harmonics form within the insonated tissue as a consequence of nonlinear sound propagation. Imaging with endogenously formed harmonics means that the distorting layer of the body wall is traversed only once by the harmonic beam--during echo reception. Both image contrast and lateral resolution are improved in harmonic mode compared with conventional (fundamental mode) sonography. This article summarizes the physics and various implementations of harmonic imaging mode, and reviews the clinical applications that have emerged to date.

View details for DOI 10.1053/sult.2001.20872

View details for Web of Science ID 000167475600002

View details for PubMedID 11300583

Abstract

We correlated the sonographic appearance of bowel wall thickening with the acuity of the underlying disease process.Sonograms of thickened bowel walls were reviewed in 37 patients with proven gastrointestinal abnormalities. Sonographic findings were correlated with clinical presentation, endoscopy, histology, laboratory data, barium studies, and CT.Twenty-eight patients presented acutely, and nine patients had chronic or subacute disease processes. Two of the 28 patients had concurrent acute and chronic processes. In 27 of 28 patients with acute processes, the abnormal bowel segments were characterized by an echogenic submucosal layer thicker than 2.5 mm. In contrast, nine patients with chronic or subacute processes had relatively uniform hypoechoic thickening of the bowel wall with loss of visualization of a discrete echogenic submucosal layer. CT was available for comparison in 30 of 37 patients. Of the 28 patients with acute abnormalities, the thickened echogenic submucosal layer on sonography corresponded to either low-attenuation submucosal edema (n = 25) or acute submucosal hemorrhage (n = 3).The finding of a thickened submucosal layer suggests an acute disease process of the bowel and corresponds to either submucosal edema or hemorrhage.

View details for Web of Science ID 000165454600022

View details for Web of Science ID 000081010900009

View details for PubMedID 10397096

Abstract

We have synthesized and evaluated five series of polymeric gadolinium chelates which are of interest as potential MRI blood pool contrast agents. The polymers were designed so that important physical properties including molecular weight, relaxivity, metal content, viscosity, and chelate stability could be varied. We have shown that, by selecting polymers of the appropriate MW, extended blood pool retention can be achieved. In addition, relaxivity can be manipulated by changing the polymer rigidity, metal content affected by monomer selection, viscosity by polymer shape, and chelate stability by chelator selection.

View details for Web of Science ID 000080553100007

View details for PubMedID 10346865

Abstract

The authors compared the time course and blood pool and hepatic enhancement of three different doses of liposomal iodixanol with those of iohexol.A liposomal iodixanol formulation was prepared with 200 mg of iodine per milliliter total and 80 mg of iodine per milliliter encapsulated. Twelve normal New Zealand white rabbits divided into four groups received 75-, 100-, or 150-mg encapsulated iodine per kilogram doses of liposomal iodixanol or 2 mL/kg iohexol with 300 mg of iodine per milliliter. A liver section was scanned with serial computed tomography (CT) before the injection, immediately afterward, and at 1-minute intervals for 10 minutes. Region-of-interest measurements of the aorta and liver were plotted at each time point, and contrast enhancement was plotted as a function of time and iodine dose.All liposomal iodixanol doses produced greater liver enhancement than iohexol. Results were significant (P < .05) for 100 mg and 150 mg iodine per kilogram dose groups at time points beyond 2 minutes. Peak hepatic enhancement (change in attenuation) was 54.9 HU +/- 7.6 with iohexol, compared with 59.6 HU +/- 6.1, 73.3 HU +/- 3.6, and 104.1 HU +/- 8.8 for 75, 100, and 150 mg encapsulated iodine per kilogram doses, respectively. Hepatic enhancement increased rapidly after injection of liposomal iodixanol, plateauing 2-3 minutes later. Blood pool enhancement decreased rapidly. Steady-state liver enhancement with liposomal iodixanol increased linearly with dose. Aortic enhancement was greater with iohexol.Liposomal iodixanol yielded greater hepatic enhancement at lower total iodine doses than iohexol. Although liver enhancement occurred rapidly after injection, blood pool enhancement was brief.

View details for Web of Science ID 000086025000006

View details for PubMedID 10898037

View details for Web of Science ID 000078596000006

View details for PubMedID 10064411

Abstract

The authors assessed the efficacy of two gadolinium-based polymers used as lymphotrophic contrast media for computed tomography (CT) and magnetic resonance (MR) imaging.Two gadolinium-based polymers, gadolinium diethylenetriaminepentaacetic acid (DTPA)-co-1,6-diaminohexane (NC 22181) and Gd-DTPA-co-alpha, omega-diamino-polyethylene glycol(1450) (NC-66368), were formulated at a concentration of 80 mmol/L gadolinium. Doses of 0.1, 0.25, 1.0, or 2.0 mL per paw were administered subcutaneously into the hindpaws of normal rabbits. Spin-echo T1-weighted MR imaging (1.5 T) of rabbit popliteal and iliac nodes was performed before and immediately, 10 minutes, 2-3 hours, and 24 hours after injection. CT was performed 2-3 hours after injection of the high doses only.MR imaging revealed prompt enhancement of the popliteal nodes with both polymers at doses of 0.25 mL and above. For doses of 1.0 mL or less per paw, nodal percentage enhancement was maximal at 2 hours and then declined at 24 hours. At the highest doses, however, a reservoir of subcutaneous contrast material remained at the injection site and resulted in peak enhancement at 24 hours. At CT, popliteal node enhancement was faintly visible 2-3 hours after the administration of NC 22181. At lower doses, no enhancement was appreciable at CT.At 80 mmol/L formulations, the two gadolinium-based polymers provide excellent popliteal nodal enhancement on MR images. In addition, high doses of one polymer (NC 22181) were sufficiently concentrated in popliteal nodes to be visible on CT scans. Thus, this agent may be useful for both CT and MR lymphography.

View details for Web of Science ID 000086024500006

View details for PubMedID 12680433

Abstract

The purpose of this study was to evaluate the safety and efficacy of OptiMARK (gadoversetamide injection) compared with Magnevist (gadopentetate dimeglumine) in hepatic MRI of patients with suspected liver pathology. A Phase III, multicenter, randomized, double-blind, parallel group study was performed in adults with suspected liver pathology. All patients underwent contrast-enhanced computed tomography within 3 weeks prior to magnetic resonance scanning. Ninety-nine patients received OptiMARK, and 94 patients received Magnevist at a dose of 0.1 mmol/kg. Precontrast T1- and T2-weighted spin-echo imaging and T1-weighted gradient-echo imaging were performed, followed by T1-weighted gradient-echo imaging at 15-20 seconds, 1 minute, and 5 minutes after intravenous contrast injection. Three primary efficacy endpoints (confidence in lesion diagnosis, level of conspicuity, and lesion border delineation) were evaluated on the precontrast image set and compared with the pre plus postcontrast image set. Vital signs, physical examination, electrocardiograms (ECGs), and laboratory parameters (chemistry, hematology, and urinalysis) were measured at various time points. Adverse events were recorded. The study design and statistical analyses were chosen to demonstrate presumed equivalence of OptiMARK and Magnevist. There were no statistically significant differences in efficacy between OptiMARK and Magnevist as assessed by either blinded readers or the on-site principal investigators. No serious or unexpected adverse events were noted. Of the 193 patients receiving contrast media, 82 experienced a total of 154 adverse events. Thirty-three (21.4%) of these 154 adverse events were felt by the on-site investigators to be probably related to either study agent: 15 events in 9 patients in the OptiMARK group, and 18 events in 13 patients in the Magnevist group. Headache was the most common adverse event, occurring in 10.1% of the OptiMARK patients and 12.8% of the Magnevist patients. No clinically relevant trends were observed in any laboratory parameter or ECG findings in either treatment group. The results demonstrate the safety, efficacy, and equivalence of OptiMARK and Magnevist at a dose of 0.1 mmol/kg in hepatic magnetic resonance imaging of patients with suspected liver pathology.

View details for Web of Science ID 000080144400014

View details for PubMedID 10077020

Abstract

The objective of our study was to determine the value of using color and power Doppler sonography to reveal extrathyroidal feeding arteries in the detection of abnormal parathyroid glands.Forty-four patients with primary hyperparathyroidism were imaged prospectively with high-resolution gray-scale, color flow, and power Doppler sonography. The presence of extrathyroidal arteries supplying the adenomas was noted. All patients underwent subsequent neck exploration. The locations of the abnormal glands were recorded.At surgery, 51 abnormal parathyroid glands were removed in the 44 patients. Sonography correctly revealed an adenoma in 40 of the 44 patients. Likewise, sonography revealed 42 of the 51 adenomas. Nine false-negative and two false-positive interpretations of the sonograms were made. Thus, overall sensitivity was 83%, specificity was 98%, and accuracy was 94%. Three of the false-negative interpretations were ectopic glands within the superior mediastinum. Excluding these three glands from analysis, the sensitivity for detection of adenomas within the neck was 88%, specificity was 98%, and accuracy was 95%. An extrathyroidal artery leading to a parathyroid adenoma was seen in 35 of the 42 adenomas revealed by sonography. The presence of an extrathyroidal artery leading to an adenoma was found to aid in the detection of an otherwise inconspicuous parathyroid gland in five patients, which improved sensitivity from 73% to 83%.Prominent vessels supplying parathyroid adenomas are frequently revealed by color flow and power Doppler sonography. These vessels can serve as "road maps" to abnormal parathyroid glands.

View details for Web of Science ID 000075496700057

View details for PubMedID 9725323

Abstract

Solitary fibrous tumor of the pleura (previously known as benign fibrous mesothelioma or pleural fibroma) can have a wide variety of appearances on imaging examinations. This essay reviews some of the lesion's more dramatic features.

View details for Web of Science ID 000071112300007

View details for PubMedID 9440836

Abstract

Macromolecular contrast media offer potential advantages over freely diffusible agents in magnetic resonance (MR) imaging outside the central nervous system. To identify an optimum molecular weight for macromolecular contrast media, the authors studied a novel macromolecular contrast agent, gadolinium diethylenetriaminepentaacetic acid polyethylene glycol (DTPA-PEG), synthesized in seven polymer (average) molecular weights ranging from 10 to 83 kd. Twenty-eight rabbits bearing V2 carcinoma in thighs underwent T1-weighted spin-echo imaging before injection and 5-60 minutes and 24 hours after injection of the Gd-DTPA-PEG polymers or Gd-DTPA at a gadolinium dose of 0.1 mmol/kg. Tumor region-of-interest measurements were obtained at each time point to determine contrast enhancement dynamics. Blood-pool enhancement dynamics were observed for the Gd-DTPA-PEG polymers larger than 20 kd. Polymers smaller than 20 kd displayed dynamics similar to those of the freely diffusible agent Gd-DTPA. Above the 20 kd threshold, tumor enhancement was more rapid for smaller polymers. The authors conclude that the 21.9-kd Gd-DTPA-PEG polymer is best suited for clinical MR imaging.

View details for Web of Science ID A1994NP29200033

View details for PubMedID 8061449

Abstract

Thirteen patients with scaphoid fractures and four patients with Kienbock's disease of the lunate underwent magnetic resonance imaging (MRI) prior to surgery. A total of 28 specimens had MR-histologic correlation. Biopsy specimens obtained by curettage provided pathologic correlation. MRI proved accurate in prospective evaluation of bone viability for both scaphoid fractures and Kienbock's disease. Normal marrow signal was shown to correlate with the presence of osteoid and osteocytes on light microscopy and a surface layer of fluorescence reflecting tetracycline uptake in viable bone. Decreased marrow signal corresponded to non-viable trabeculae with scant osteoid, without osteocytes and no tetracycline labeling. By virtue of its accurate identification of avascular necrosis, MRI may prove valuable in predicting prognosis for patients with scaphoid fractures and Kienbock's disease of the lunate.

View details for Web of Science ID A1990DP66500002

View details for PubMedID 2392023

Abstract

Thirty-two patients with symptoms referable to the brachial plexus were evaluated with magnetic resonance (MR) imaging. Sixteen patients had undergone concurrent computed tomography (CT). MR imaging demonstrated normal findings in 16, 12 neoplasms, three cases of trauma, and one case of possible neural edema. Of the 16 patients with normal findings on MR images, eight had CT scans that were also normal. In one patient, MR images showed that the "mass" seen on CT was actually a tortuous blood vessel. In six of the 12 cases of neoplasm in which CT scans were available, MR imaging revealed more extensive disease. In the other six cases of tumor, MR imaging provided sufficient clinical information to obviate the need for CT or any other imaging modality. MR imaging provided definitive diagnoses in the three cases of trauma without further imaging. In one patient with paresthesia, MR imaging showed high signal intensity of the nerves on T2-weighted images, which was compatible with neural edema. A concurrent CT scan was normal.

View details for Web of Science ID A1988M653600035

View details for PubMedID 3347719