Use of sitting position to relieve myelographic obstruction.

In some patients with lumbar spinal stenosis, opacification of the subarachnoid space beyond the stenosis is difficult to achieve during myelography. A second lumbar puncture caudal to the obstruction or computed tomography is often required to complete the examination. We encountered this difficulty in seven patients with this condition, and when the patients assumed a sitting position during the examination, the contrast material was able to flow beyond the obstruction .