Demonstration of nerve roots on unenhanced computed tomographic scans.

Small foci of high attenuation are seen within the subarachnoid space on high resolution axial transverse computed tomography (CT) of the lumbar spine. By use of reformatted images in oblique planes, these foci form linear structures of high attenuation corresponding to the nerve roots of the cauda equina. Unenhanced CT is therefore capable of demonstrating the nerves of the cauda equina in selected cases.