Thirteen patients with prior cervical spinal cord injury resulting in quadriplegia were evaluated with magnetic resonance imaging (MRI) long after their initial injury, either because of the relatively recent onset of new and worsening neurologic symptoms or to rule our residual compression on the spinal cord or nerve roots. The results of MRI were compared with delayed metrizamide computed tomography (CT) in 10 cases, and in five of those the results were also compared with intraoperative spinal sonography. It was found that MRI more accurately demonstrated the intramedullary abnormalities in the injured spinal cord than did delayed metrizamide CT because the former could separate myelomalacia from a posttraumatic spinal cord cyst, a differentiation that was frequently difficult with delayed metrizamide CT. T2-weighted spin-echo pulsing sequences with long echo times were particularly useful in evaluating these patients.