Spinal epidural abscess: evaluation with gadolinium-enhanced MR imaging.

Magnetic resonance (MR) imaging with gadopentetate dimeglumine was performed in 25 patients with spinal epidural abscess (SEA). Seventeen of 25 patients underwent follow-up MR imaging. The studies were retrospectively reviewed. In 20 patients, diskitis was the primary infectious foci; however, five patients developed diffuse SEA without diskitis. The two most common MR appearances were (a) homogeneous or heterogeneous enhancement of the solid portion of the SEA and (b) thin or thick enhancement around the liquefied collections of pus. Dural enhancement was frequently seen in patients with lengthy vertebral involvement of SEA. Engorgement of the epidural venous plexus or basivertebral veins was occasionally observed. The changes in abscess size noted on follow-up studies correlated well with clinical improvement or deterioration in most patients. Persistent contrast enhancement, however, was frequently noted at the site of diskitis, osteomyelitis, or surgical drainage sites despite clinical improvement. Careful correlation of MR imaging findings with clinical findings and laboratory data is important in predicting prognosis for these patients.