Gd-DTPA enhanced MR of the lumbar spinal canal in patients with claudication.

Abstract

The purpose of this work was to study the findings on intravenous gadolinium-enhanced MRI of the lumbar spinal canal in patients with clinically suspected neurogenic claudication. A prospective gadolinium-enhanced MR evaluation of seven adult patients presenting with clinical claudication thought to be related to the lumbosacral spine was undertaken. Of seven consecutive enhanced conventional SE MRI examinations of the lumbosacral spine in patients presenting with lower extremity claudication, five patients (71.4%) revealed abnormal intrathecal enhancement on MR at and extending craniad from the level(s) of severe spinal stenosis. Each of the seven patients (100%) showed relatively severe central stenosis of the lumbar spinal canal. The enhancement pattern was linear, curvilinear, punctate, and/or diffuse in configuration. Two of the five patients with intrathecal enhancement also showed similar abnormal intrathecal enhancement extending caudal to the severely stenotic levels. The clinically significant intrathecal enhancement on intravenous gadolinium-enhanced MRI identified above the level of a severely stenotic lumbar spinal canal hypothetically might represent enhancement of dilated, obstructed venous structures serving the cauda equina. More likely, however, the major factor in such enhancement at, above, and/or below the stenosis signals blood-nerve barrier breakdown associated with mechanical injury, inflammatory response, and wallerian degeneration/regeneration of axons within chronically compressed nerve roots.