Discography

Abstract

Indications

Discography is a diagnostic tool for the diagnosis of cervical, thoracic, or lumbar radicular or referral pain. Although the use of discography as the first-line diagnostic examination is not indicated, it is usually recommended when conservative treatment or noninvasive diagnostic tools fail to establish a reasonable outcome. It is reserved for suspicious abnormalities seen on other tests and when severe symptoms are propelling the patient toward the surgery. Discography is mainly valuable for its provocative nature of intrinsic derangement of disks responsible for somatic back pain and referred pain.

The main indications for discography are as follows:

• Highly suspicious disk disease in the absence of MRI, CT, or myelographic findings, or when the results of these tests are equivocal

• Provocation discography to localize the main disk culprit for patient's symptoms when multiple disk herniations at different levels are found on MRI, CT, or myelography

• Differentiation between scar tissue and recurrent disk in a patient with prior surgery of the spine who presents with low back pain

• Differentiation between a symptomatic disk and pseudarthrosis in a patient with posterior or lateral fused segment to assess postsurgical failed back syndrome

• Diagnosis of a painful Schmorl node, a painful incompletely healed end-plate fracture, or a painful established nonunion vertebral fracture

• Investigation of disks higher or lower to a fused segment in a patient with spinal fusion

• Before injection of cortisone or anesthetic in the disk

• To undertake interventional procedures on the disk

Contraindications

Discography is an invasive procedure and is not recommended as the first-line diagnostic examination for the diagnosis of discogenic radicular or referral pain. It should not be performed in patients with sepsis, cellulitis, osteomyelitis, diskitis, severe bleeding diathesis, cauda equina syndrome, vertebral fractures, or segmental instability seen on flexion-extension films or with severe degeneration associated with spondylolisthesis. Intervertebral disk collapse, severe disk space narrowing, sequestered disk herniations, and large disk protrusions are also relative contraindications.

Equipment (Optimal and Including Contrast Media)

• Sedatives such as midazolam, plus analgesics

• Local anesthetic

• For lumbar discography: a 15-cm long 18-gauge and a 20-cm long 22-gauge needle (or a 15-cm 21-gauge and 18-cm 26-gauge needle)

• For cervical discography: a 23-gauge 3.5-in spinal needle

• For thoracic discography: a 15- to 20-cm long 22-gauge needle (or a 15-cm long 21-gauge or 17-cm long 26-gauge needle for a double-lumen technique)

• Nonionic contrast agent (e.g., Omnipaque 180)

Technique