Abdominal tuberculous lymphadenopathy: MRI features.

The aim of this study was to describe the MRI features of abdominal tuberculous lymphadenopathy. MRI studies of 13 patients with abdominal tuberculous lymphadenopathy were reviewed with regard to anatomic distribution and size. Signal intensities, in relation to abdominal wall muscle, on unenhanced T1- and T2-weighted images and patterns of contrast enhancement of lymphadenopathy were evaluated in each patient. In each patient, the largest lymph node with the same imaging characteristic was evaluated. The upper paraaortic region was the most common site of involvement (n=12 patients), followed by the lesser omentum (n=10 patients), the anterior pararenal space (n=9 patients), the lower paraaortic area (n=8 patients), the small bowel mesentery (n=6 patients), the greater omentum (n=2 patients) and the originating site of the inferior mesenteric artery (n=2 patients). The mean lymph node size was 1.8 cm (range 0.5-5 cm). The overall mean lymph node number per patient was 16 (range 2-50). A total of 41 lymph nodes were evaluated in 13 patients. On T2-weighted images, 40 lesions were hyperintense and one lesion was isointense. Nine hyperintense lesions showed a hypointense peripheral rim and seven internal heterogeneïty. Perinodal T2-hyperintensity was present in 23 lesions. The latter finding was valid for all patients. On T1-weighted images, 30 lesions were hypointense and 11 isointense. Nine hypointense lesions demonstrated a hyperintense peripheral rim, and six were heterogeneous. Contrast-enhanced fat-suppressed T1-weighted images demonstrated predominant peripheral enhancement in 28 lesions: (1) peripheral uniform, thin (n=19); (2) thick irregular, complete (n=3); and (3) conglomerate group of nodes showing peripheral and central areas of rim enhancement (n=6). Heterogeneous and homogeneous enhancement was present in ten and three lesions, respectively. Combinations of enhancing patterns in the same nodal group and different nodal groups were seen in eight and nine patients, respectively. Abdominal tuberculous lymphadenopathy may show a variety of signal intensities and patterns of contrast enhancement on MRI. Lymphadenopathy, hypointense on T1-weighted, hyperintense on T2-weighted images with perinodal hyperintensity, and predominant peripheral rimlike enhancement may suggest the diagnosis of tuberculosis.