Interpreting spine imaging in pain practice

Degenerative spine findings are near universal with age and often painless; image only for red flags or when results would change management, and interpret any finding against the clinical picture, remembering that large herniations often shrink.

1. Degeneration is normal aging. In 3110 asymptomatic people, disc degeneration rose from 37% at age 20 to 96% at 80, and disc bulges from 30% to 84% ¹.
2. Context decides relevance. Many degenerative features are part of normal aging and unrelated to pain, so they must be interpreted in the clinical context; these findings become more common with each decade ¹.
3. Image selectively. ACP advises imaging low back pain only with severe or progressive neurologic deficits or features suggesting a serious or specific underlying condition ².
4. Routine imaging adds harm, not benefit. In other patients routine imaging is not associated with clinically meaningful benefit and can lead to harms and downstream costs; more testing does not equal better care ².
5. Bigger herniations regress more. In conservatively treated lumbar herniations, spontaneous regression occurred in 96% of sequestrations, 70% of extrusions, 41% of protrusions and 13% of bulges ³.
6. Most acute back pain improves anyway. ACP notes most acute or subacute low back pain improves over time regardless of treatment, favoring heat, massage, acupuncture or manipulation first ⁴.

Degenerative findings are common in pain-free people, so interpret them only alongside the history and examination; conversely, normal imaging does not exclude a painful facet joint, and imaging cannot confirm which joint hurts ¹⁵.

• Complete resolution occurred in 43% of sequestrated and 15% of extruded discs ³.
• Extrusions and sequestrations regress significantly more often than bulges or protrusions ³.
• Disc protrusion prevalence in pain-free adults rose from 29% at 20 to 43% at 80 ¹.
• Annular fissures appeared in 19% of pain-free 20-year-olds and 29% of 80-year-olds, so fissures are common in people without pain ¹.
• For suspected stenosis, NASS suggests MRI as the most appropriate noninvasive test (grade B) ⁶.
• MRI best shows soft disc herniation and myelomalacia; CT better shows bony impingement, and CT myelography substitutes when MRI is impossible ⁷.
• Selective imaging, per the ACP and American Pain Society guideline, improves outcomes and reduces costs ².
• In cervical facet pain, imaging cannot identify the painful joint, and CT shows facet arthritis in many people scanned for other reasons ⁵.

• Attributing chronic back pain to a disc bulge seen on MRI ¹.
• Ordering MRI for uncomplicated acute back pain without red flags ².
• Selecting a facet joint for ablation from imaging changes rather than diagnostic blocks ⁵.
• Assuming a large extrusion or sequestration will persist; these regress most often ³.