MRI findings of DREZ-otomy lesions.

Pre- and postoperative MR findings in the spinal cord of 4 patients who underwent lesioning of the cervical dorsal root entry zone (DREZ-otomy) are reported. In 3 patients with root avulsion, MR images revealed spinal cord atrophy preoperatively and, after DREZ-otomy, long-lasting spinal cord enlargement and extensive intramedullary changes. In a case without root avulsion, the preoperative MR study showed no apparent abnormality and the only postoperative MR change was a discrete lesion well confined to the dorsal horn. The findings suggested basically different post-operative pathology among patients with root avulsion and those without. MRI can be a useful supplement to autopsy study in defining postoperative spinal cord changes after DREZ-otomy.