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Objective: The purpose of our study was to determine the efficacy of percutaneous thrombin treatment for iatrogenic pseudoaneurysms of the femoral artery in comparison with sonographically guided compression repair., Subjects and Methods: Twenty-three pseudoaneurysms occurring after catheterization were treated percutaneously with an initial injection of 1.0 mL of thrombin solution via a 22-gauge spinal needle under continuous sonographic guidance. Four patients required the additional injection of 1.0-4.0 mL of thrombin for complete thrombosis. Repeated sonography was performed 24 hr after injection. Additionally, we compared our results with those of a control group by reviewing the imaging findings and medical records of 16 patients who underwent sonographically guided compression of iatrogenic pseudoaneurysms between January 1998 and July 1998., Results: Twenty-two of 23 pseudoaneurysms occurring after catheterization were successfully treated with percutaneous thrombin injection. One recurrence was identified 24 hr after injection in a patient who experienced a significant complication. Procedure time was limited to 15 min with an overall success rate of 96%. Retrospectively, 18 iatrogenic pseudoaneurysms were identified in 16 patients. Six (60%) of 10 pseudoaneurysms were successfully compressed under sonographic guidance, with an average time to thrombosis of 32 min. Compression was unsuccessful for four pseudoaneurysms with an average compression time of 45 min. Compression could not be performed in seven patients (39%). The overall success rate of sonographically guided repair was 60%., Conclusion: Preliminary evidence suggests that sonographically guided percutaneous thrombin injection is a safe and effective method of treatment for iatrogenic pseudoaneurysms and offers significant advantages over conventional sonographically guided compression.

Objective: The purpose of our study was to assess the accuracy of CT-guided biopsy of musculoskeletal neoplasms with respect to technique, anatomic site, and histology., Materials and Methods: During a 3-year period (January 1992 to December 1994), 176 core needle biopsies and 45 fine-needle aspirations were performed under CT guidance on patients with musculoskeletal neoplasms. To assess the accuracy of these procedures, we compared the diagnosis at biopsy with the final diagnosis as determined at the time of definitive treatment of the lesion. All biopsy findings were categorized as a primary malignancy (excluding round cell lesions), round cell lesion, local recurrence, or metastatic carcinoma. In addition, each lesion was analyzed according to which biopsy technique was used, whether frozen tissue section or rapid cytologic evaluation was used, and at which anatomic site the mass was found., Results: The accuracy for needle biopsy was 93% and that for fine-needle aspiration was 80%. The complication rate for both techniques was less than 1%. Accuracy rates for the four categories of primary malignancy, round cell lesion, local recurrence, and metastatic carcinoma were 87%, 75%, 94%, and 100%, respectively. The mismatch rates were similar in soft-tissue lesions (5/52) and bone lesions (16/169). Diminished accuracy was associated with round cell lesions (20%) and lesions located in the spine or the perivertebral region (20%). Nondiagnostic and insufficient specimens were found in 18 (8%) of the 221 patients. CONCLUSION. CT-guided biopsy of musculoskeletal malignancies is a safe and effective procedure if performed by a team of clinicians, pathologists, and radiologists who possess subspecialty expertise.

Objective: We have implemented computerized speech recognition in a high-volume clinical setting using a newly developed commercial software system. This paper compares the performance of the computerized system with conventional transcription during a trial week followed by 3 months of routine clinical use., Conclusion: The speech recognition system was used for 97% of the cases during the trial week and 87% of cases during the months of continuous use. For a similar mixture of cases, no change occurred in the length of reports after introduction of the computerized system. Speech recognition decreased the time until the report became available by 99% and resulted in a substantial savings in transcription costs. We conclude that speech recognition by computer is practical in a high-volume clinical implementation.

Objective: The purpose of this study was to determine if kinematic CT can be applied to the patellofemoral joint using current slip-ring CT scanner design in patients with anterior knee pain and thus a suspected patellar tracking disorder., Subjects and Methods: Twenty knees in 18 patients with anterior knee pain were evaluated with kinematic CT. A single 10-sec exposure of the patellofemoral joint was obtained during active flexion and extension. Static nonkinematic and loaded kinematic examinations were compared with unloaded kinematic studies in a subset of patients. The changes in lateral patellofemoral angle and lateral shift were measured. Video cine viewing of patellofemoral motion was used to subjectively grade image quality and patellofemoral abnormalities by consensus., Results: Kinematic CT was successfully used in all 20 knees. In nine knees studied with static nonkinematic and unloaded kinematic images, the lateral patellofemoral angle improved an average of 4" on the kinematic images. In addition, lateral shift improved by an average of 3%, an improvement that was statistically significant (p = .01). In 10 knees studied with and without loading, the lateral patellofemoral angle decreased an average of 3% with loading. No significant change was seen in lateral shift. In all patients, cine viewing was thought to be more useful than single images. Cine viewing was of good or diagnostic quality in all 20 knees studied. Lateral patellar translation during extension was detected in eight of 20 kinematic studies. Lateral patellar tilting also was detected in eight of 20 kinematic studies. Narrowing of the articular space was detected in 12 of 20 knees. Six knees were determined to be normal., Conclusion: Kinematic CT with slip-ring technology is a new technique that can be easily performed on the patellofemoral joint. This technique shows promise as a tool for determining the cause of anterior knee pain.

Objective: We describe a method for capturing measurement data directly from digitized images using specialized software and high-resolution workstations. We have evaluated the reliability, accuracy, and reproducibility of this method in an international clinical trial involving vertebral morphometry., Materials and Methods: Accuracy was determined using clinical radiographs measured with vernier calipers and a film phantom. Intra- and interobserver variabilities were assessed, and longitudinal reproducibility was evaluated. As part of the trial, spinal radiographs were collected from more than 200 international health care facilities and digitized at four screening centers. Digitized images were stored and sent to our central facility for morphometry and archiving. Timeliness and variability of the process were tracked., Results: Relative accuracy was nearly 100%. Correlation with clinical measurements was high (r = .96; p < .05). The mean coefficient of variation for interobserver variability was 2%. Intraobserver variation was 3-5%. The coefficient of variation for longitudinal reproducibility ranged from 4% to 6%. After 9 months of operation, our trial included 9494 patients. Of approximately 36,000 radiographs, 98% passed quality review. Only 1% of vertebral levels were not measurable. Hardware and software problems were minimal., Conclusion: The use of digitized images for morphometry is accurate, reproducible, and convenient. When applied to a large-scale clinical trial, it offers unique advantages that may justify the cost and complexity that exceed those of conventional radiographs.

Objective: Three elderly women with osteoporotic compression fractures of a vertebral body underwent MR imaging because of neurologic signs and symptoms. Atypical fluid collections were shown by MR imaging in all three patients. For histologic characterization of these vertebral fluid collections, CT-guided biopsies and aspirations were done for all three patients., Conclusion: After studying the clinical, histologic, and imaging features of these fluid collections associated with vertebral fracture, we suggest that they are most likely associated with underlying avascular necrosis.

Objective: We studied the MR imaging characteristics of the articular muscle of the knee, an important but seldom recognized structure of the distal thigh and knee., Subjects and Methods: We used a 1.5-T system to prospectively evaluate the articular muscle of the knee in five healthy volunteers (10 knees); then we retrospectively studied the knee examinations of 24 patients (30 knees). One reader made duplicate readings to prospectively assess the sagittal proton density-weighted and axial T1-weighted images of the healthy volunteers. Three independent readers retrospectively evaluated the sagittal proton density-weighted images of the 24 patients., Results: The articular muscle of the knee was identified in 100% of prospective studies (10/10) and in 83% of retrospective studies (25/30). For the prospective study group, measurements (mean +/- SEM) were as follows: number of bundles, 2.4 +/- 0.68 (range, 1-4); length of uppermost bundle, 47.2 +/- 4.06 mm; width of origin, 8.6 +/- 0.79 mm; angle of origin, 11.4 degree +/- 1.29 degree; and cross-sectional bundle width, 19.8 +/- 2.05 mm2., Conclusion: The articular muscle of the knee can usually be identified by MR imaging as an independent entity, separate from the great (vastus) muscle group.

CT scanning is used frequently to assess the condition of patients after liver transplantation. The CT records of 174 adult patients who underwent liver transplantation were studied retrospectively to determine the number and timing of CT studies as well as the frequency and significance of the findings. One-hundred seventy CT scans were obtained in 66 (38%) of the 174 patients, with a mean of 2.6 scans/patient. The interval between transplantation and scanning was 1 day to 24 months; in 59 (89%) of 66 patients, the first CT scan was obtained within 30 days. The acute indications for CT scanning were fever or leukocytosis in 54 (92%) of 59 patients and abnormal liver function tests in five (8%) of 59 patients. CT scans obtained more than 30 days after transplantation were repeat scans in all but seven patients. Indications in this latter group were the same as for the acute group, plus evaluation of hepatic neoplasia in three patients. CT findings included periportal low attenuation in 41 (62%) of 66 patients; ascites in 25 (38%); splenomegaly in 19 (29%); loculated intraperitoneal noninfected fluid collections in 13 (20%); intrahepatic, splenic, pancreatic, or perihepatic abscesses in seven (11%); hepatic infarction in six (9%); splenic infarction in three (4%); and hepatic calcification in two (3%). Other major abnormalities included inferior vena caval thrombosis (one patient), pseudoaneurysm of the hepatic artery with rupture (one patient), and recurrent hepatocellular carcinoma (one patient). CT scanning after liver transplantation is used predominantly in the acute setting to evaluate for liver infarction or intraabdominal abscess. In this setting, CT showed these abnormalities, in addition to tumor recurrence or vascular abnormalities, in 15 (23%) of 66 patients.