MRI OF AIDS-RELATED POLYRADICULOMYELITIS

Objective: We describe the unusual syndrome of cytomegalovirus (CMV) p olyradiculomyelitis and its MR findings in two patients with AIDS. Mat erials and Methods: The clinical records and MRI studies of two patien ts with AIDS and CMV polyradiculomyelitis were reviewed. The MR images were performed on a Picker 1.0 or 1.5 T MR unit. Axial and sagittal T 1-weighted images of the lumbar spine were obtained, pre- and post-Gd- DTPA (0.1 mmol/kg) administration. Gradient echo sagittal images were also obtained. Results: Precontrast images demonstrated a thickened ca uda equina in both patients. In one patient the conus was ill defined on precontrast images. Postcontrast images demonstrated diffuse enhanc ement of the cauda equina in both patients as well as enhancement alon g the surface of the conus. In one patient the nerve roots were clumpe d and adherent to the walls of the thecal sac as well as to other nerv e roots. Conclusion: The clinical presentation of urinary retention, f laccid paraparesis, back and/or leg pain, and ''saddle anesthesia'' in a patient with AIDS should suggest the diagnosis of CMV polyradiculom yelitis. Although diffuse enhancement of the cauda equina on postcontr ast MRI is a nonspecific finding, it would strongly support this diagn osis in the appropriate clinical setting. The diagnosis may be easily missed without the use of a contrast agent.