Thoracic Discography

Discography in the thoracic spine requires a high-resolution, multidirectional C-arm device with filming capability and a tilting table with a movable top.12,15,22 Review of previous thoracic MR imaging studies is required prior to the procedure, to rule out the presence of either spinal cord compression or cord deformity at or adjacent to any level to be studied. The discographer must have knowledge of spinal canal dimensions prior to undertaking the procedure. We avoid the study of any segment in which spinal cord compression and/or deformity exists, and we on occasion decline the procedure altogether when we are asked to inject discs deforming the cord and there is accompanying myelopathy. Each case of cord impingement with or without myelopa-thy must be considered individually.

To perform thoracic discography safely, one must avoid the lung, which is anterior and lateral to the needle route into the disc (Figure 6.7), and the spinal cord, which is dorsal and medial to the route employed.15

Figure 6.7. A. 20° oblique projection revealing the optimal route of thoracic disc access (arrow). Needle passes through the square space between rib head (dot) and thoracic facet joint on left.

Figure 6.7. A. 20° oblique projection revealing the optimal route of thoracic disc access (arrow). Needle passes through the square space between rib head (dot) and thoracic facet joint on left.

Thoracic Disc

The needle is generally directed between 15 and 30° oblique to the AP projection. Each disc access route is determined fluoroscopically prior to skin marking, sterile preparation, and needle introduction. Lower and midthoracic discs can be easily and safely studied in most individuals, while high (T5-6 and above) thoracic discs may be extremely difficult, in some cases impossible, to reach. As one ascends in the thoracic spine, the route of access disappears owing to the shorter disc height and more close approximation of the ribs and costovertebral joints. Such factors as disc height, spinal deformity, and costovertebral and vertebral body os-teophytes will affect the accessibility of individual thoracic discs.

In most cases, we employ 25-gauge, 3.5 in. spinal needles for thoracic discography; for large patients, however, a 5 in., 22-gauge needle may be required and is entirely safe to use. Once needle placement has been accomplished, the injection and filming are performed, and the responses recorded, in identical fashion to that described for lumbar discography (Figures 6.8-6.10). In most cases, clinically suspect, abnormal-appearing thoracic discs (seen on MR studies) are studied,

Abnormal Lumbar Disc Images Discogram

Figure 6.8. Painfully deranged T11-12 disc exhibiting a mixture of venous opacification and epidural leakage of contrast material during injection. (A) AP film reveals lateral leakage of contrast (arrow) into paraspinous veins and tissues. (B) Lateral view demonstrates posterior leakage into epidural space and veins (heavy straight arrow). Note anterior tear (curved arrow). Patient, who reported 8/10 concordant back and abdominal pain, had been through extensive and unreveal-ing gastrointestinal evaluation for abdominal pain prior to discography.

Figure 6.8. Painfully deranged T11-12 disc exhibiting a mixture of venous opacification and epidural leakage of contrast material during injection. (A) AP film reveals lateral leakage of contrast (arrow) into paraspinous veins and tissues. (B) Lateral view demonstrates posterior leakage into epidural space and veins (heavy straight arrow). Note anterior tear (curved arrow). Patient, who reported 8/10 concordant back and abdominal pain, had been through extensive and unreveal-ing gastrointestinal evaluation for abdominal pain prior to discography.

along with at least one adjacent and/or nearby control level, as in the lumbar region. Postdiscography CT scans may be helpful in individual circumstances; however, as in the lumbar spine, this is not a routine in our practice. Clinical investigation involving chronic pain sufferers and asymptomatic volunteers has revealed that MR imaging is generally insensitive in the detection of painful thoracic disc annular tears.22

Thoracic disc degeneration and annular tears are a frequent cause of clinical pain and disability (Figures 6.8 and 6.9).22 Thoracic annular tears, with or without frank disc protrusion and/or endplate disruption (Scheuermann's disease or Schmorl's nodes) (Figure 6.10)15,23 frequently result in clinical pain, disability, and painful discographic responses. Thoracic disc pathology often results in extraspinal presen-

Thoracic Discography Pictures

Figure 6.9. Painfully deranged T6-7 disc with epidural leakage of contrast. (A) AP and (B) lateral images obtained during injection reveal contrast leakage into the epidural space (arrows). Patient reported 8.5/10 concordant back, bilateral rib cage, and intrathoracic pain produced with injection.

Figure 6.9. Painfully deranged T6-7 disc with epidural leakage of contrast. (A) AP and (B) lateral images obtained during injection reveal contrast leakage into the epidural space (arrows). Patient reported 8.5/10 concordant back, bilateral rib cage, and intrathoracic pain produced with injection.

T12 Discogram Images

Figure 6.10. Painfully deranged T12-L1 disc due to endplate infractions (Schmorl's nodes). Lateral image obtained during injection reveals Schmorl's nodes (arrows) involving both adjacent endplates. Circumferentially, disc annulus was fully intact. Patient reported 7/10 concordant lower thoracic and upper lumbar pain provoked with injection.

tations of pain, with or without back pain (Figures 6.8 and 6.9). Thoracic disc lesions may produce complaints involving the chest wall, visceral thoracic and upper abdominal structures, and the lumbar and sacral region. Discography response cannot be predicted in the thoracic spine based upon imaging studies.22 We have observed that thoracic discography has become an indispensable procedure in the investigation of pain that may have originated in the thoracic spine.

Was this article helpful?

+1 0
Back Pain Relief

Back Pain Relief

This informational eBook will present you with the most recent research and findings available so that you can learn more about Back Pain relief, covering as many bases as possible from A to Z.

Get My Free Ebook


Responses

  • swen
    How painful is a thoracic discogram?
    8 years ago

Post a comment