Discography: A Diagnostic Tool for Spinal Pain

Discography, also referred to as a discogram, is an invasive diagnostic procedure used to assess the structural integrity and pain-generating potential of intervertebral discs within the spine. It is most commonly performed in patients with chronic back or neck pain whose symptoms have not been adequately explained by noninvasive imaging studies such as magnetic resonance imaging (MRI) or computed tomography (CT). By identifying whether a specific disc is the source of pain, discography assists clinicians in determining appropriate treatment strategies, including the potential need for surgical intervention.

This article outlines the purpose, methodology, clinical indications, risks, benefits, and diagnostic value of discography to provide a comprehensive understanding of its role in spinal pain evaluation.

What Is Discography?

Discography is a diagnostic procedure in which contrast material is injected into the nucleus pulposus of an intervertebral disc under fluoroscopic guidance. The objective is twofold: to assess the internal structure of the disc and to determine whether pressurization of the disc reproduces the patient’s characteristic pain.

Unlike MRI or CT scans—which primarily evaluate anatomical changes—discography is a functional test designed to provoke symptoms. It is particularly useful when imaging findings do not correlate with clinical symptoms or when multiple discs demonstrate degenerative changes, making it difficult to identify the primary pain source.

Why Is Discography Performed?

Discography is typically reserved for carefully selected patients with persistent spinal pain and is most often utilized in the following clinical scenarios:

1. Chronic, Unexplained Pain

Patients with ongoing neck or back pain that has not responded to conservative treatments such as physical therapy, medications, or injection-based therapies, and where the pain source remains unclear.

2. Preoperative Assessment

Discography may be used prior to spinal surgery—such as spinal fusion or artificial disc replacement—to confirm the specific disc responsible for pain, ensuring accurate surgical targeting.

3. Multilevel Disc Degeneration

When imaging studies reveal abnormalities at multiple disc levels, discography can help identify which disc is symptomatic versus those that are degenerative but asymptomatic.

4. Differentiating Pain Sources

The procedure assists in distinguishing discogenic pain from pain arising from other spinal structures, including facet joints, ligaments, or paraspinal musculature.

How Is Discography Performed?

Discography is conducted in a hospital or outpatient surgical setting under strict sterile conditions. The procedure typically includes the following steps:

1. Patient Preparation

The patient is positioned on a fluoroscopy table, and the skin over the target area is sterilized. Local anesthesia is administered to numb the insertion site, and mild sedation may be provided if needed.

2. Needle Placement

Using real-time fluoroscopic guidance, a thin needle is carefully advanced into the center of the intervertebral disc. Depending on symptoms, multiple discs may be evaluated during the same session.

3. Contrast Injection

Contrast dye is slowly injected into the disc to increase internal pressure. The physician assesses whether the injection reproduces the patient’s typical pain and asks the patient to describe the quality, location, and intensity of symptoms.

4. Imaging Assessment

Fluoroscopic images, and often a post-procedure CT scan, are obtained to evaluate the distribution of contrast within the disc. A healthy disc typically retains the dye centrally, while a degenerated disc may show fissures or leakage through the annulus fibrosus.

5. Post-Procedure Monitoring

After the procedure, the patient is observed briefly for any immediate complications. Most individuals can resume normal activities within 24–48 hours, although mild soreness is common.

What Does Discography Reveal?

Discography provides both functional and structural diagnostic information:

1. Pain Provocation Response

Reproduction of the patient’s usual pain during injection strongly suggests that the tested disc is a pain generator.

2. Disc Structural Integrity

Imaging reveals internal disc abnormalities, such as annular tears or degeneration of the nucleus pulposus, based on the pattern of contrast spread.

Risks and Potential Complications

Although discography is generally safe when performed by experienced clinicians, it carries inherent risks associated with invasive procedures. These include:

1. Infection

A small risk of infection, including discitis, exists despite strict sterile technique.

2. Bleeding

Minor bleeding at the needle insertion site may occur, particularly in patients with clotting disorders or those on anticoagulant therapy.

3. Post-Procedural Pain

Temporary exacerbation of pain is common due to disc irritation and typically resolves within a few days.

4. Nerve Injury

Rarely, needle placement may irritate or injure adjacent nerves, leading to transient numbness or tingling.

5. Contrast Allergy

Allergic reactions to contrast material are uncommon but possible; patients should disclose any known allergies beforehand.

Benefits of Discography

When appropriately indicated, discography offers several clinical advantages:

1. Precise Identification of Pain Source

By correlating pain reproduction with disc pressurization, discography can confirm discogenic pain.

2. Enhanced Surgical Planning

Accurate identification of the symptomatic disc improves surgical precision and may enhance postoperative outcomes.

3. Diagnostic Clarity

Discography can resolve diagnostic uncertainty in cases with inconclusive or conflicting imaging findings, helping avoid unnecessary or inappropriate interventions.

Conclusion

Discography remains a valuable diagnostic modality for evaluating chronic spinal pain when conventional imaging fails to provide definitive answers. While it carries certain risks, careful patient selection and expert technique can yield critical information that guides effective treatment planning, including surgical decision-making. Patients experiencing persistent, unexplained back or neck pain should discuss the potential benefits and risks of discography with their healthcare provider to determine whether it is an appropriate diagnostic option for their condition.