Spinal epidural abscess with gadolinium-enhanced MRI: serial follow-up studies and clinical correlations.

We reviewed serial MRI with and without gadolinium-DTPA in eight patients with spinal epidural abscess and correlated the findings and the clinical manifestations. In four patients, diffuse abscesses spanned four vertebral bodies or more; the others had focal abscesses associated with osteomyelitis and/or diskitis. In three of the four patients with diffuse abscesses, MRI (NCMRI) showed diffuse encasement of the subarachnoid space. Contrast-enhanced MRI (CEMRI) demonstrated linear enhancement surrounding unenhanced pus. In the four patients with focal abscesses, CEMR delineated the inflammatory process more clearly than NCMR. On follow-up studies, decrease in abscess size and better visualization of the subarachnoid space correlated with clinical improvement in both diffuse and focal abscesses. Despite clinical improvement, contrast enhancement persisted in the disk or epidural space of three patients, and was thought to represent chronic granulomatous change or postsurgical scar. CEMR is very valuable for the initial diagnosis of an epidural abscess, particularly if it involves lengthy segments. During follow-up, CEMR can document responses to therapy, and provide information for determining appropriate treatment.