Biomedical subjects
Publications and source records attributed to Michael L Richardson.
OBJECTIVE: This study was designed to test our hypothesis that football players with shoulder pain, shoulder instability, or both requiring MR arthrography for evaluation are at an increased likelihood relative to non-football players for having a tear of the posterior glenoid labrum. CONCLUSION: We conclude that posterior glenoid labrum tears are more prevalent in football players than in non-football players.
OBJECTIVE: We discuss the case of a 20-year-old woman who presented with a bone mass in the anterior aspect of the distal femur. Radiographs and CT showed a predominantly mature bony mass on the surface of the cortex with a smaller, less mineralized soft-tissue component. MRI showed hyperintensity in the soft-tissue component on T2-weighted images and contrast enhancement following gadolinium infusion. The final pathologic diagnosis was parosteal osteosarcoma. CONCLUSION: A wide variety of unusual, benign bone lesions that often have little clinical significance have been described in the literature. It is important to distinguish lesions that require specific therapy from those that do not; it is much less important to try to obtain a specific imaging diagnosis for lesions that do not require therapy.
OBJECTIVE: In this article, we describe a user-friendly Web-based interface that allows review of images combined with integrated data collection and entry for use at multiple sites involved in a large multicenter research project. CONCLUSION: The Web-based system that we present uses a commercially available Internet browser and Web platform and allows automated data entry that can be easily uploaded into standard data analysis programs. The system simplifies the complex logistics of using multiple sites and reviewers for radiology research and can preserve human subject confidentiality. We tested the system using a large-scale multicenter cohort study of pelvic fracture-related hemorrhage (the "Evaluating Pelvic Hemorrhage" study). Program testing revealed seamless remote image interpretation and data acquisition.
Explore the source record for details and available documents.
OBJECTIVE: To determine whether current-generation endoluminal ultrasonic transducer technology could visualize dysplastic and malignant cervical lesions. METHODS: Inclusion criteria for patients enlisted in the study were abnormal Papanicolaou test results, an abnormality seen at colposcopy, and consent for a cone biopsy. In addition, we included 4 women who were undergoing hysterectomy but had no evidence of cervical abnormalities at the time of surgery, for a total of 28 women. We used a 20-MHz annular array intravascular transducer. We correlated all sonographic and pathologic results with regard to being normal or abnormal using the Pearson product moment correlation coefficient, and we evaluated interobserver variation by having 5 blinded sonologists interpret each examination and calculating kappa statistics. RESULTS: We performed intracervical sonography on 24 women with abnormal Papanicolaou test results and on 4 women without abnormalities. Nineteen of the 24 women with proven disease had abnormal sonographic images. Five women with pathologically proven cervical intraepithelial neoplasia I had normal sonographic images. Lesions ranged in size from 0.3 to 7 mm. Two carcinomas (5 and 7 mm diameter), multiple nabothian cysts, cervicitis, and 2 giant cell foreign body reactions were visible on sonography. The correlation coefficient for abnormal sonographic and pathologic findings was 0.87 (P < .005). We obtained a kappa value of 0.75 for interobserver variation. CONCLUSIONS: Intracervical sonography was able to visualize dysplastic lesions and carcinomas as hypoechoic defects with surrounding echogenic areas of glandular cervical mucosa. Lesions were shown with sufficient resolution and interobserver variation to suggest that the technique may be clinically applicable, particularly for planning surgical therapy. However, design of a transducer that can be easily sterilized between examinations, similar to current endovaginal probes, would be necessary to make intracervical sonography a clinically feasible examination.
OBJECTIVE: To identify any clinical and radiologic findings of rotator cuff injury that predict whether patients will undergo shoulder surgery. METHODS: We retrospectively studied all shoulder sonograms obtained at a single institution over 12 months. Possible predictors of surgical treatment were documented, including patient age and sex, duration and types of symptoms, and the location and severity of tendon damage on sonography. One hundred twenty-eight patients underwent shoulder sonography; 34 patients eventually underwent shoulder surgery. Multivariate logistic regression was performed to identify clinical and sonographic factors associated with the use of surgical therapy. RESULTS: The only statistically significant predictor of surgical intervention was the finding of full-thickness tears (with or without tendon retraction) on sonography (P = .03). Patients with full-thickness tears were 4.3 times more likely to undergo surgery than those with no tears (odds ratio, 4.3). CONCLUSIONS: The sonographic diagnosis of full-thickness rotator cuff tears is the only finding statistically associated with the use of surgical treatment. No single clinical variable was consistently associated with subsequent surgery. Partial-thickness tears on sonography also do not show any statistical association with the eventual use of surgery for rotator cuff symptoms.
BACKGROUND: The capsule and ligaments are generally viewed as the primary stabilizers of the glenohumeral joint, but many important activities are performed in midrange positions in which these structures are lax. HYPOTHESIS: In vivo, the humeral head can be centered in the glenoid, even when the shoulder is in positions in which the capsule is lax and even when the shoulder is passively positioned. STUDY DESIGN: Controlled laboratory study. METHODS: We documented the centering of the humeral head in the relaxed shoulders of six subjects using open-magnet magnetic resonance imaging scans. RESULTS: While these shoulders were passively placed in midrange positions (those not at the extremes of motion), the humeral head center was never more than 2.2 mm from the glenoid center (mean + 0.1 +/- 1.2 mm). CONCLUSIONS: The results suggest that mechanisms other than ligamentous restraint, such as the compressive effect of resting muscle tone into the conforming concavity of the glenoid, may be sufficient to maintain centering of the glenohumeral joint. Further exploration of these mechanisms may lead to methods other than ligament tightening or capsular shrinkage for restoration of stability to joints that are unstable in the midrange of motion. CLINICAL RELEVANCE: In that many patients with unstable shoulders demonstrate instability in midrange positions, it is hoped that further study of living shoulders will lead to a more effective understanding of the nonligament mechanisms of shoulder stability and the ways in which these stabilizing mechanisms can be restored.