(2) Patient supine. This technique may be used when a relatively large
amount of contrast medium is injected. After completion of the injection, the needle is
withdrawn and the patient is placed in the supine position on the tilt-table unit. The
table is tilted and desired. The flow of the contrast medium is observed fluoroscopically
and spot-films are taken in various positions as indicated.
(3) Removal of contrast medium. When the examination has been
completed, the head-end of the table is raised so that the patient is brought to the
vertical (or near-vertical) position, thereby pooling the contrast medium in the lumbar
subarachnoid space for subsequent removal.
(4) Incidental blockage. In the event of incidental blockage of the spinal
canal due to pathologic condition in the thoracolumbar region, it may be necessary for
the examiner to inject the medium by means of cisternal puncture. In this case, the
tilting procedure is the reverse of that used for the lumbar-puncture method.
h. Cervical Myelography. The patient is placed in the prone position on the tilt-
table unit, with the head fully extended. The head must be fully extended to prevent the
contrast medium from entering the cranial cavity. Contrast medium is introduced into
the lumbar subarachnoid space in a manner similar to that in lumbar myelography. By
lowering the head-end of the table, the examiner maneuvers the column of contrast
medium from the lumbar region toward the cervical subarachnoid space. This is done
under fluoroscopic control. Spot-film exposures are made for the sagittal projections.
Lateral projections of the cervical region are obtained with the radiographic tube and a
horizontal CR. After completion of the examination, the contrast medium is pooled
under the lumbar-puncture needle for subsequent removal.
Removal of Contrast Medium from the Subarachnoid Space of the
Spine. Removal of contrast medium is done only under fluoroscopic control. Two
methods are described below.
(1) In one method, the patient is placed in the prone position on the tilt-table
unit. By appropriate tilting of the table and under fluoroscopic control, the column of
contrast medium is pooled under the spinal-puncture needle. An unused sterile syringe
is then attached to the needle and the contrast medium is carefully aspirated. In case
the needle was withdrawn immediately after the introduction of the contrast medium, a
second spinal puncture is performed over the area and the contrast medium is removed
as described above. Before the needle is withdrawn, a radiograph, or a fluoroscopic
examination should be made to determine if satisfactory removal has been
accomplished. If satisfactory removal is confirmed, the needle is withdrawn and the
patient is returned to the ward.