This article discusses the range of manifestations of tuberculosis (TB) of the abdomen, including involvement of the gastrointestinal tract, the peritoneum, mesentery, omentum, abdominal lymph nodes, solid abdominal organs, the genital system and the abdominal aorta. Abdominal TB is a diagnostic challenge, particularly when pulmonary TB is absent. It may mimic many other abdominal diseases, both clinically and radiologically. An early correct diagnosis, however, is important in order to ensure proper treatment and a favorable outcome. Modern imaging is a cornerstone in the early diagnosis of abdominal TB and may prevent unnecessary morbidity and mortality. Generally, CT appears to be the imaging modality of choice in the detection and assessment of abdominal tuberculosis, other than gastrointestinal TB. Barium studies remain superior for demonstrating mucosal intestinal lesions. Ultrasound may be used for follow-up to monitor therapy response. The diagnosis of abdominal TB should be considered if suggestive imaging findings are found in patients with a high index of suspicion.

The aim of this study was to determine whether pre-operative MR mammography could predict the extent of breast cancer in patients with dense breasts or whether dense parenchyma will lead to false-positive or inconclusive examinations. Sixty-seven patients with dense breasts with a malignant breast tumor planned for conservative surgery were reviewed. Detection rates of mammography, ultrasound, and MR mammography were studied, and the diameters of the lesions were measured and compared with pathological examination. Pathology revealed breast cancer in 65 patients. Sensitivity for detection of index lesions was 83% for mammography, 70.8% for ultrasound, and 98% for MR mammography. Mammography underestimated tumor extent in 37%, ultrasound in 40%, and MR in 12.5%. Of the 20 patients (31%) with multifocal or multicentric carcinoma, mammography detected the lesions in 35%, ultrasound in 30%, and MR in 100%, with a false-positive rate of 12.5, 14, and 23%. The MR mammography is more accurate in assessing tumor extent and multifocality in patients with dense breasts, but benign changes may lead to false-positive examinations.

nal intensities on T1-and T2-weighted images, contrast enhancement, relationship with adjacent fascia or tendon, secondary bone involvement, and intratumoral necrosis. In 19 cases the pathology findings were available for review and for a comparative MR-pathology study.Results. On T1-weighted images, lesions were isointense (n=3), hypointense (n=7) or slightly hyperintense to muscle (n=11). Immunohistochemical examination was performed in 17 patients. All 17 specimens showed positivity for HMB-45 antibody. In nine of 11 lesions with slightly increased signal intensity on T1-weighted images, a correlative MR imaging-pathology study was possible. All nine were positive to HMB-45 antibody. Conclusions. Clear cell sarcoma of the musculoskeletal system often has a benign-looking appearance on MR images. In up to 52% of patients, this lesion with melanocytic differentiation has slightly increased signal intensity on T1-weighted images compared with muscle. As the presence of this relative higher signal intensity on T1-weighted images is rather specific for tumors displaying melanocytic differentiation, radiologists should familiarize themselves with this rare entity and include it in their differential diagnosis when confronted with a well-defined, homogeneous, strongly enhancing mass with slightly higher signal intensity compared with muscle on native T1-weighted images. Abstract Objective. To evaluate MR imaging and pathology findings in order to define the characteristic features of clear cell sarcoma of the soft tissues (malignant melanoma of the soft parts). Design and patients. MR examinations of 21 patients with histologically proven clear cell sarcoma of the musculoskeletal system were retrospectively reviewed and assessed for shape, homogeneity, delineation, sig- Key words

To investigate the use of MRI in preoperative characterization of invasive lobular breast cancer (ILC) and in detection of multifocal/multicentric disease. We retrospectively reviewed T1-weighted FLASH 3D precontrast and postcontrast MR images together with subtraction images of 26 women with histopathologically proven invasive lobular cancer. Two experienced radiologists described tumor patterns of ILC independently. MR findings of unifocal, multifocal, single quadrant and multiquadrant disease were correlated with results of other imaging techniques and compared with histopathological findings as gold standard. Most ILC presented on MRI as a single spiculated/irregular, inhomogeneous mass (pattern 1, n=12) or as a dominant lesion surrounded by multiple small enhancing foci (pattern 2, n=8). Multiple small enhancing foci with interconnecting enhancing strands (pattern 3) and an architectural distortion (pattern 4) were both described in three cases. There was one case of a focal area of inhomogeneous enhancement (pattern 5) and one normal MR examination (pattern 6). Unifocal and multifocal lesions were identified on MRI in four patients with normal conventional imaging. In nine women, multiple additional lesions or more extensive multiquadrant disease were correctly identified only on MRI. MRI may play an important role in the evaluation of patients with ILC, which is often difficult to diagnose on clinical examination and conventional imaging and more likely occur in multiple sites and in both breasts. However, false-negative MR findings do occur in a small percentage of ILC.