[Diagnosis and therapy of lateral intervertebral disk displacements. I. Normal roentgen anatomy of the lumbar nerve roots in computer tomography].

As a basis for the CT diagnosis of lateral disc herniations, the normal anatomy of the nerve roots from L4 to S1 within the lateral recess, is described and compared with the myelographic and CT findings. In myelograms, the roots can be demonstrated from where they leave the dural sac, for about the height of one vertebral body as far as the spinal ganglion in the upper part of the intervertebral foramen, where the subarachnoid space terminates. By non-enhanced CT, the roots can be distinguished from the surrounding fat only in the widening lower part of the lateral recess. The ganglion and the spinal nerve can be shown in the intervertebral foramen and further distally where they can no longer be seen on the myelogram,. Thus, of both these complementary techniques, CT s more suitable for the diagnosis of lateral disc herniations.