MR of omental myelosynangiosis.

PURPOSE To describe MR findings in patients who have undergone omental transposition (omental myelosynangiosis) for spinal cord revascularization.

METHODS Spin-echo MR images, without and with intravenous gadolinium, were obtained before and after surgery in three patients using 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 serpiginous areas of flow void, which extends through the laminectomy site to lie directly adjacent to the cord surface. MR angiography demonstrated small omental vessels, some coursing to the omentum-cord interface; however, no definite extension into the cord was detected. In all patients, there was alteration in cord size and contour after transposition, but no change in cord signal. Clinical improvement was observed in one of the three patients. The signal characteristics of the transposed omentum changed, showing less homogeneity and a gradual loss of the signal over a period of 4 months.

CONCLUSIONS MR delineates transposed omentum and associated postoperative changes in omental myelosynangiosis. MR angiography is useful as an adjunct to demonstrate the small vessels near the omentum-cord interface, but lacks sufficient resolution to demonstrate neoangiogenesis within the cord.