What Does the Conus Medullaris Location Mean on a Lumbar MRI?

Short answer: the conus medullaris is the tapered lower end of the spinal cord. Lumbar MRI reports often state where it ends, and that line is commonly included as a normal anatomy check.

What the wording usually describes

Many reports say the conus ends near L1 or L1-L2 and has normal signal. That is usually reassuring language. It becomes more important if the report suggests an abnormal level, abnormal signal, tethering concern, mass effect, or if symptoms include serious neurologic changes.

Details that make the finding more or less important

the exact level where the conus ends
whether the report says normal signal or abnormal signal
whether there is mention of tethering, mass, or severe canal narrowing
whether there are bowel, bladder, saddle numbness, or progressive weakness symptoms
whether leg symptoms match nerve-root findings lower in the report instead

How to discuss it at a pain visit

If the conus sentence is described as normal, ask what other findings better match the symptoms. If bowel/bladder changes, saddle numbness, or progressive weakness are present, that deserves prompt medical review.

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

Sources include NCBI Bookshelf - Neuroanatomy Spinal Cord, 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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