The imaging findings of impingement syndromes of the lower limb.

In this article we provide an overview of impingement syndromes of the lower limb. At the level of the hip, femoroacetabular and ischiofemoral impingement are recognised. At the level of the knee, we discuss Hoffa's fat pad impingement, suprapatellar fat pad impingement, pericruciate impingement, and iliotibial band syndrome. The impingement syndromes associated with anterior cruciate ligament (ACL) repair and intercondylar osteophytes are also illustrated. Most impingement syndromes are described at the level of the ankle. These include, anterior, anterolateral, posterior, anteromedial, posterior, and posterolateral impingement. For these conditions, we describe the best technique and expected imaging findings. It should be kept in mind that many of these findings have been observed in the asymptomatic population. Impingement is essentially a clinical diagnosis and imaging findings should be considered as supportive elements for this clinical diagnosis.

Development of a full body CAD dataset for computational modeling: a multi-modality approach.

The objective of this study was to develop full body CAD geometry of a seated 50th percentile male. Model development was based on medical image data acquired for this study, in conjunction with extensive data from the open literature. An individual (height, 174.9 cm, weight, 78.6 ± 0.77 kg, and age 26 years) was enrolled in the study for a period of 4 months. 72 scans across three imaging modalities (CT, MRI, and upright MRI) were collected. The whole-body dataset contains 15,622 images. Over 300 individual components representing human anatomy were generated through segmentation. While the enrolled individual served as a template, segmented data were verified against, or augmented with, data from over 75 literature sources on the average morphology of the human body. Non-Uniform Rational B-Spline (NURBS) surfaces with tangential (G1) continuity were constructed over all the segmented data. The sagittally symmetric model consists of 418 individual components representing bones, muscles, organs, blood vessels, ligaments, tendons, cartilaginous structures, and skin. Length, surface area, and volumes of components germane to crash injury prediction are presented. The total volume (75.7 × 103 cm(3)) and surface area (1.86 × 102 cm(2)) of the model closely agree with the literature data. The geometry is intended for subsequent use in nonlinear dynamics solvers, and serves as the foundation of a global effort to develop the next-generation computational human body model for injury prediction and prevention.

Transperineal ultrasound-guided radioactive seed implantation for organ-confined carcinoma of the prostate.

PURPOSE: This retrospective study was undertaken to: (a) determine the prognostic significance of pretreatment and 1-year nadir serum prostate specific antigen (PSA) levels in organ-confined carcinoma of the prostate treated with ultrasound-guided radioactive 125I seed implantation; (b) determine the factors associated with postimplant morbidity and whether modification of the technique would reduce morbidity; (c) evaluate the local control rate and disease-free survival of patients undergoing seed implantation. METHODS AND MATERIALS: From October 1988 through December 1992, 142 patients with organ-confined adenocarcinoma of the prostate and a Gleason score < or = 7 underwent ultrasound-guided radioactive 125I seed implantation as an alternative to radical prostatectomy. Patients were considered to have persistent or progressive disease if there was evidence of local progression on digital exam, or if there were two consecutive increases in the PSA level. Patients suspected of persistent or progressive disease underwent restaging to include CT scan of the pelvis, bone scan, and ultrasound-guided prostate biopsy. Patients with increasing PSA levels in which active disease could not be confirmed were considered biochemical failures with occult systemic disease and were offered hormone ablation. RESULTS: With 1-6-year follow-up, median 30 months, the relapse patterns were prostate 4 (2.8%), bone 4 (2.8%), rising PSA 16 (11%). Pretreatment PSA level correlated with subsequent recurrence; pretreatment PSA < or = 4 (0), 4.1 to 10 (14%), 10.1 to 20 (21%), 20.1 to 50 (58%). Disease free survival at 2 years was 90% and at 5 years 76%. Nadir PSA (nPSA) at 1 year also correlated with recurrence: nPSA < or = 1 (3%), nPSA 1 < or = 4 (50%), and nPSA > or = 4 (100%). Seed implantation was well tolerated with 31% of patients experiencing RTOG morbidity > or = Grade 2, which typically consisted of transient radiation urethritis, which resolved with conservative measures. Eleven (8%) experienced RTOG morbidity > or = Grade 3. There was no correlation between number of seeds or total millicuries implanted and subsequent morbidity. However, reduction in the periurethral seed intensity reduced > or = Grade 3 morbidity from 11 to 4%. CONCLUSION: Ultrasound-guided radioactive seed implantation provides excellent local control of 97%, with a median 30 month follow-up. Morbidity is comparable to other curative modalities and by modifying Blasko's technique to reduce radioactive seed strength in the periurethral area, significant morbidity is rare. Pretreatment PSA and the nadir PSA at 1 year are important predictors of subsequent disease outcome. With a liberal definition of systemic recurrence as two consecutive increases in PSA levels, the 5-year disease-free survival is 76%.