Discography¶
Definition¶
Discography (provocative discography) is a diagnostic procedure in which contrast is injected directly into an intervertebral disc under fluoroscopic guidance. Its primary purpose is to determine whether a specific disc is the source of a patient's pain by reproducing their concordant symptoms during injection, and to evaluate the internal architecture of the disc (annular integrity).
Technique¶
Procedure¶
- Patient positioning: prone or lateral decubitus
- Fluoroscopic guidance: a spinal needle is advanced into the nucleus pulposus of the target disc using anteroposterior and lateral fluoroscopy
- Contrast injection: non-ionic iodinated contrast is slowly injected while monitoring:
- Opening pressure and volume accepted
- Pain response — the patient reports whether the injection reproduces their typical pain (concordant) or produces a different pain (discordant) or no pain
- Post-discography CT: thin-section CT is performed to evaluate the contrast distribution pattern within the disc
Dallas Discogram Classification (Modified)¶
Describes the pattern of contrast spread within the disc on post-discography CT:
| Grade | Pattern |
|---|---|
| Grade 0 | Contrast contained within the nucleus pulposus |
| Grade 1 | Contrast extends into the inner annulus |
| Grade 2 | Contrast extends into the outer annulus |
| Grade 3 | Contrast extends to the outer annulus margin |
| Grade 4 | Contrast extends beyond the annulus (extrusion) |
| Grade 5 | Contrast extends beyond the annulus and dissects into the epidural space |
Interpretation Criteria¶
A disc is considered the pain source when: - Injection reproduces the patient's concordant pain (the same pain they experience clinically) - At least one adjacent control disc does not reproduce concordant pain - The pain response is rated ≥6/10 - The disc shows annular disruption (Grade 2 or higher) on post-discography CT
Indications¶
- Evaluation of discogenic pain when non-invasive imaging is inconclusive
- Pre-surgical planning — identifying the specific pain-generating disc level(s) before fusion surgery
- Evaluation of adjacent discs before extending a planned fusion
- Differentiating symptomatic from asymptomatic disc degeneration (many degenerative discs are painless)
Clinical Pearl
Discography is one of the most controversial diagnostic procedures in spine medicine. Proponents argue it is the only test that directly correlates a specific disc with pain reproduction. Critics cite concerns about false-positive rates (up to 25–40% in some studies), subjective pain assessment, potential acceleration of disc degeneration from needle puncture, and the risk of discitis. The SPORT trial and subsequent studies have raised questions about its predictive value for surgical outcomes. Many spine surgeons and societies now recommend caution in its use, and some have abandoned it entirely.
Complications¶
- Discitis — the most serious complication; infection rate ~0.1–0.5% per disc; minimized by strict sterile technique and prophylactic intradiscal antibiotics (cefazolin)
- Accelerated disc degeneration — needle puncture of the annulus may promote degenerative changes
- Allergic reaction to contrast
- Neural injury — rare; from misdirected needle
- Epidural abscess — rare extension of discitis
Limitations¶
- Subjective — relies on patient pain reporting; influenced by psychological factors
- False positives — reported in patients with chronic pain syndromes, anxiety, and depression
- Invasive — risk of discitis and potential disc injury
- Controversial evidence — limited evidence that discography-guided surgical decisions improve outcomes compared to decisions based on MRI alone
- Not a standalone test — must be interpreted in conjunction with clinical findings and MRI
Key Points¶
- Discography assesses whether a disc reproduces the patient's concordant pain
- Post-discography CT evaluates annular integrity and contrast spread pattern
- It is controversial — concerns about false positives, subjective interpretation, and potential disc damage
- Discitis is the most serious complication (~0.1–0.5% per disc)
- Many surgeons now rely on MRI and clinical correlation rather than discography for surgical planning
- When used, strict criteria (concordant pain ≥6/10 with negative control level) improve specificity
References¶
- Gruver C, Guthmiller KB. Provocative Discography. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; updated 2023 May 23. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470389/
- Stretanski MF, Vu L. Fluoroscopy Discography Assessment, Protocols, and Interpretation. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; updated 2023 Jul 10. Available from: https://www.ncbi.nlm.nih.gov/books/NBK572119/
- Modified Dallas discographic classification of intervertebral disc radial tears. Radiopaedia.org. Available from: https://radiopaedia.org/articles/modified-dallas-discographic-classification-of-intervertebral-disc-radial-tears
- Sachs BL, Vanharanta H, Spivey MA, Guyer RD, Videman T, Rashbaum RF, et al. Dallas discogram description. A new classification of CT/discography in low-back disorders. Spine (Phila Pa 1976). 1987;12(3):287-94.
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- Carragee EJ, Tanner CM, Khurana S, Hayward C, Welsh J, Date E, et al. The rates of false-positive lumbar discography in select patients without low back symptoms. Spine (Phila Pa 1976). 2000;25(11):1373-80.
- Carragee EJ, Don AS, Hurwitz EL, Cuellar JM, Carrino JA, Herzog R. 2009 ISSLS Prize Winner: Does discography cause accelerated progression of degeneration changes in the lumbar disc: a ten-year matched cohort study. Spine (Phila Pa 1976). 2009;34(21):2338-45.
- Manchikanti L, Benyamin RM, Singh V, Falco FJ, Hameed H, Derby R, et al. An update of the systematic appraisal of the accuracy and utility of lumbar discography in chronic low back pain. Pain Physician. 2013;16(2 Suppl):SE55-95.
- Bartynski WS, Rothfus WE, Kurs-Lasky M. Postdiskogram CT features of lidocaine-sensitive and lidocaine-insensitive severely painful disks at provocation lumbar diskography. AJNR Am J Neuroradiol. 2008;29(8):1455-60.