Characteristic heterotopic ossification of the proximal humerus after total shoulder arthroplasty.

Objective: A bony spur in a characteristic location involving the proximal humerus is identified on post-operative radiographs in some patients with history of total shoulder arthroplasty. The spur is theorized to represent heterotopic ossification near the attachment site of the pectoralis major tendon on the proximal humerus which is partially detached and then reattached during total shoulder arthroplasty. In this study, we determine the morphology, incidence, demographic associations, and clinical impact of this finding.

Comparison of Pre-Revision Magnetic Resonance Imaging and Operative Findings in Mechanically Assisted Crevice Corrosion in Symptomatic Metal-on-Polyethylene Total Hip Arthroplasties.

Background: Failed total hip arthroplasty (THA) caused by mechanically assisted crevice corrosion (MACC) has serious consequences-notably, adverse local tissue reactions. Metal artifact reduction sequence (MARS) magnetic resonance imaging (MRI) has been used to evaluate failed THA for other reasons but has not been assessed for the analysis of cases of MACC in the setting of metal-on-polyethylene arthroplasties.

Methods: We examined the correlation between preoperative MARS MRI and surgical findings in a cohort of 20 consecutive patients undergoing revision THA for symptomatic MACC without other associated orthopedic diagnoses.

Differentiation of hepatocellular carcinoma and hepatic metastasis from cysts and hemangiomas with calculated T2 relaxation times and the T1/T2 relaxation times ratio.

Purpose: To determine the diagnostic capability of the T1 and T2 relaxation times and the T1/T2 relaxation times ratio generated with the mixed turbo spin echo (mixed-TSE) pulse sequence, in order to discriminate between hepatocellular carcinoma (HCC)/metastases and hemangiomas/cysts.

Materials And Methods: A retrospective review of 36 MR examinations implementing the mixed-TSE pulse sequence demonstrated 70 focal hepatic lesions. Quantitative MR algorithms were used to generate T1 and T2 relaxation times, and the T1/T2 relaxation times ratio for each lesion.

Liver and spleen volumetry with quantitative MR imaging and dual-space clustering segmentation.

The purpose of this HIPAA-compliant, institutional review board-approved study was to assess the liver and spleen volumes calculated by using a semiautomated dual-space clustering segmentation technique, as compared with the volumes calculated by using the manual contour-tracing method. The quantitative magnetic resonance (MR) imaging data used as input were computed from images acquired by using a mixed fast spin-echo pulse sequence that was implemented with respiratory triggering. Linear regression analysis was used to assess agreement regarding the volumes calculated by using both segmentation techniques.