What Do Clumped Nerve Roots or Arachnoiditis Wording Mean on MRI?

Short answer: clumped nerve roots is MRI language that can raise the possibility of arachnoiditis or scarring/inflammation around nerve roots, but the meaning depends on the full report, history, and symptoms.

What the wording usually describes

This wording should not be interpreted from one phrase alone. Prior surgery, infection, bleeding, severe stenosis, procedures, inflammatory conditions, and technical imaging details can all affect how a clinician interprets the finding.

Details that make the finding more or less important

whether the radiologist explicitly says arachnoiditis or only describes clumping
whether there is severe stenosis that could crowd nerve roots
whether there has been prior spine surgery, infection, trauma, or other relevant history
whether symptoms include severe nerve pain, numbness, weakness, or bowel/bladder changes
whether comparison imaging shows a new or longstanding appearance

How to discuss it at a pain visit

Bring the complete report and relevant history. Ask what the radiologist and clinician think is most likely and whether any urgent neurologic symptoms require immediate evaluation.

Related PSG resources: lower back pain, sciatica, and pain management.

Sources include NCBI StatPearls - Arachnoiditis, RadiologyInfo - MRI Spine, NINDS - Low Back Pain Fact Sheet. This article is educational and cannot diagnose the cause of pain from an imaging phrase alone.

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