MR OF OMENTAL MYELOSYNANGIOSIS

PURPOSE: To describe MR findings in patients who have undergone omenta l transposition (omental myelosynangiosis) for spinal cord revasculari zation. METHODS: Spin-echo MR images, without and with intravenous gad olinium, were obtained before and after surgery in three patients usin g a quadrature spine coil. Three-dimensional time-of-flight spinal MR angiography was also performed. RESULTS: On routine MR, the transposed omentum is an irregular, lobulated fat-equivalent mass, containing se rpiginous areas of flow void, which extends through the laminectomy si te to lie directly adjacent to the cord surface. MR angiography demons trated small omental vessels, some coursing to the omentum-cord interf ace; however, no definite extension into the cord was detected. In all patients, there was alteration in cord size and contour after transpo sition, but no change in cord signal. Clinical improvement was observe d in one of the three patients. The signal characteristics of the tran sposed omentum changed, showing less homogeneity and a gradual loss of the signal over a period of 4 months. CONCLUSIONS: MR delineates tran sposed omentum and associated postoperative changes in omental myelosy nangiosis. MR angiography is useful as an adjunct to demonstrate the s mall vessels near the omentum-cord interface, but lacks sufficient res olution to demonstrate neoangiogenesis within the cord.