(6) Next, the smaller caliber needle (No. 22) is advanced until its tip enters
the nucleus pulposes of the intervertebral disk under consideration. In some cases, a
lateral projection is made to check the precise position of the needle. If necessary,
additional pairs of needles may be inserted in one or more of the adjacent intervertebral
(1) A syringe (for example, Luer-Lok, 10 cc) filled with approximately 5 cc of
the contrast medium consisting of one of the sterile aqueous solutions (for example,
Hypaque) and containing from 35 to 50 percent iodine compound is then attached to the
smaller caliber needle.
(2) After the specialist has readied the radiographic apparatus and placed a
cassette in the Bucky tray, the examiner injects the contrast medium into the
intervertebral disk. In the case of a normal disk, approximately 0.5 to 1 cc of the
contrast solution may be injected. If abnormal conditions are encountered, more
contrast solution may be injected--usually from 2 to 5 cc (or more).
(3) PA and lateral projections (figure 3-21) of the injected disks are obtained
as soon as possible following the injection. These radiographs are made without
changing the position of the patient. This technique usually requires a portable Potter-
Bucky diaphragm or grid-front cassettes for the horizontal CR.
(4) The examiner now removes the needles and an appropriate dressing is
applied to the puncture site. The patient is then placed in the supine position and the
spinal column is flattened by flexion of the knees. AP projections (figure 3-22) are
obtained. Stereoscopic exposures are made according to the instructions of the
(5) The table is then brought to the vertebral relationship, and lateral
projections are obtained with the patient in the standing (weight-bearing) position.
(6) All exposed films should be developed and presented to the examiner
for inspection before the patient is returned to the ward.
(7) If additional projections (for example, oblique) are required, they must be
exposed as quickly as possible; otherwise, absorption of contrast medium may diminish
radiopacification to such a degree that satisfactory radiographs cannot be obtained.