X-Ray Visualization of the Intervertebral Disk
ROBERT E. WISE, M.D.
Department of Roentgenology
EDWARD C. WEIFORD, M.D.
Department of Neurosurgery
ONE important source of interference with accuracy in the diagnosis of protruded intervertebral disks is the fact that the disk cartilage is not opaque to x-ray and therefore, for roentgen confirmation, the neurologic surgeon has had to depend upon the indirect and occasionally misleading evidence afforded by myelography. This difficulty now has been overcome by Lindblom1,2 of Sweden who described a method of x-ray visualization of the disk by injection of the nucleus pulposus with Diodrast.
In this technic, a spinal puncture is performed at the suspected level using a short fine gage lumbar puncture needle. Through this needle, another smaller gage longer needle is introduced across the spinal canal into the center of the disk. The use of this two-needle technic permits the operator to accomplish the disk puncture with so fine a needle that practically no damage results to the posterior spinal ligament or annulus fibrosis. The position of the needle is checked by x-ray. When satisfactory, 2 cc. of 35 per cent Diodrast is injected, the needles removed and x-rays made. If the disk is normal, the injection meets great resistance, is painless or may produce slight localized back pain and the resulting film shows a biloculated collection of the dye near the center of the interspace. If the disk is ruptured the injection meets little resistance, although it is apt to cause a definite exacerbation of the patient's sciatica, and the resulting film shows a wide dispersion of the dye throughout the interspace and extruding posteriorly. . .