PURPOSE: The purpose of this study is to describe the MR findings of transverse myelitis, especially on T2 weighted images and to determine if there are any MR findings characteristic of transverse myelitis that may bevaluale in the differentiation from intramedullary tumor. MATERIALS AND METHODS: The MR images of 13 patients with the diagnosis of transverse myelitis were retrospectively reviewed. The diagnosis was based on both the clinical and follow-up MR images, and was confirmed by open biopsy in four patients. The MR features were analyzed in terms of the the position and extent of the lesion, signal intensity on all sequences, enhancement patterns(nodular, patchy, linear, punctate, ring, and mixed), and the presence or absence of hemorrhage, cyst, andsyrinx. On T2-weighted images, existence of focal abnormal signal areas compatible with the enhancing lesions and shape of both rostral and caudal ends of the lesions were also evaluated. RESULTS: On MR images, there was fusiform swelling of the spinal cord over variable length from 2 to 10 vertebral segments. The lesions showed diffuse isosignal intensity on T1 weighted images and high signal intensity on T2 weighted images. Contrast-enhanced T1 weighted images revealed variable enhacement pa- tterns ; nodular in 7, patchy in 6, linear in 3, punctate in 2, ring in 1 and mixed in 6 cases. The enhancement occurred usually within the central portion of highsignal intensity lesion of the swollen cord. The cranial and caudal ends of the high signal lesion usually showed smooth tapered appearance in 12 cases(both ends in 10 and one end in 2). There was no focal abnormal signal lesion compatible with the enhancing area. No case demonstrated any hemorrhage, cyst, and syrinx. CONCLUSION: Segmental cord swelling, diffuse high signal intensity with tapered appearance of both cranial and caudal ends, and no focal abnormal signal intensity that is compatible with the enhancing lesion, suggest transverse myelitis. Therefore, if above MR findings are seen, follow-up study is recommended to avoid the invasive surgical procedures.