Purpose: To conduct a multi-center assessment of the use of a 0.2-T, extremity MR system (E-scan; General Electric Lunar Corp. and Esaote, Genoa, Italy) for identifying tears of the rotator cuff and glenoid labrum. Materials and Methods:A retrospective study was performed involving 160 patients (age range, 15-84 years old) from five facilities in the United States, comparing shoulder MR imaging to surgical findings. MR imaging of the shoulder was conducted as follows: shoulder coil; T1-weighted spin echo, coronal-oblique and axial images; short Tau inversion recovery (STIR), coronal-oblique images and axial images; and T2-weighted spin echo, coronal-oblique and sagittal-oblique images. The MR examinations were interpreted in an independent, prospective manner by two radiologists with extensive musculoskeletal MRI experience. Arthroscopic (N ϭ 103) or open surgical (N ϭ 57) procedures were performed within a mean of 53 days after MR imaging.Results: Surgical findings demonstrated rotator cuff tears in 131 patients and labral tears in 60 patients. For the rotator cuff, the sensitivity, specificity, positive predictive value, and negative predictive value were 90%, 93%, 98%, and 68%, respectively. For the labrum, the sensitivity, specificity, positive predictive value, and negative predictive value were 55%, 100%, 100%, and 82%, respectively. Conclusions:There was good agreement when MR results obtained using the extremity MR system were compared to surgical findings for identifying rotator cuff tears, while the sensitivity of MR imaging for determining labral tears was relatively poor. Nevertheless, these findings were comparable to those reported in the peer-reviewed literature for MR systems operating at mid-, and high-field-strengths. MAGNETIC RESONANCE (MR) IMAGING is regarded as a useful and accurate technique for diagnosing shoulder disorders, including rotator cuff disease and lesions of the glenoid labrum (1-16). MR imaging of the shoulder has been predominantly performed by using wholebody MR systems operating at high-field-strengths (1.0 -1.5 Tesla) or, more recently, utilizing low-fieldstrength (0.2-0.35 Tesla) scanners (1-16). In 2001, Shellock et al (3) studied the diagnostic capabilities of an extremity MR system for identifying shoulder pathology. This investigation compared MR examinations to surgical findings in 47 patients and reported good agreement with regard to determining tears of the rotator cuff and glenoid labrum. In fact, the diagnostic performance of the extremity MR system was reported to compare favorably to that of whole-body, mid-and high-field-strength MR scanners for a variety of musculoskeletal applications (17,18).Performing MR examinations of the shoulder using the extremity MR system offers distinct advantages over conventional MR systems, including reduced start-up costs, more convenient siting and installation, lower maintenance fees, and greater patient comfort and safety (17,18). Importantly, these advantageous features permit the extremity MR system to be readily utilized...

Distribution of PMOL was best assessed by bone scan. However, MRI revealed larger areas of marrow involvement and detected lesions in the pelvis not seen on bone scan. Marrow involvement around the knee was common, and the combination of skull, distal femoral and proximal tibial lesions may suggest the diagnosis. Radiographs underestimate the extent of disease but were the best modality for assessment of treatment response.

Inflammation of the wall of the gallbladder causes a loss of the integrity of its muscular layers. When this occurs there is an evagination of the mucosal lining of the gallbladder wall forming the so-called Rokitansky-Aschoff sinuses that extended to the muscular layer and often to the serosa of the gallbladder wall. These sinuses do communicate with the lumen of the gallbladder. Luschkas ducts or crypts are similar structures, with a mucosal lining; however, they do not communicate with the gallbladder lumen, but rather are attached to the inner surface of the gallbladder by a fibrous cord. This cord most likely represents the obliterated opening of the Rokitansky-Aschoff sinus due to inflammation of the wall of the gallbladder. Diverticulae of the gallbladder appear to originate in a similar manner and are not found in the normal gallbladder