Foramen
Read Your Scan Editorial Team·Last updated
Written from published radiology references and reviewed for plain language. Not written or signed by a physician, and not a diagnosis. How we write these pages →
In plain language
The small opening on each side of the spine where a nerve exits. Narrowing here is called foraminal stenosis.
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Where you'll see this
This wording turns up on Lumbar Spine MRI reports — MRI imaging of the spine. A lumbar (low-back) MRI shows the vertebrae, the cushioning discs between them, the spinal canal, and the nerves that travel to the legs. Doctors order it for low-back pain, sciatica, leg numbness or weakness, or to plan care. Importantly, many of the changes it describes are extremely common and are seen in people with no pain at all — so the report is read together with how you actually feel.
It also appears on Cervical Spine MRI.
Questions worth asking your doctor
- Do the findings on the MRI match where I actually feel pain or symptoms?
- Are these changes common for my age, or is anything unusual?
- What are my non-surgical options, such as physical therapy?
- Are there any signs that would mean I should seek care sooner?
- Do I need any follow-up imaging, and when?
How common is this?
A foramen is an opening in bone through which something passes, and in spine reporting it means the small channel on each side of the spine where a nerve root exits between two vertebrae. The plural is foramina, and they are described on every spine report because they are where nerve compression most often occurs.
When should I worry?
The foramina matter because they are narrow to begin with and get narrower with the ordinary changes of ageing — a bulging disc from the front, a worn facet joint from the back, bone spurs from either. Narrowing there is described as foraminal stenosis or foraminal narrowing, and it is graded mild to severe. What determines whether it matters is not the grade but whether symptoms follow the distribution of the nerve that exits at that level. Narrowing on a scan with no matching symptoms is extremely common and is generally left alone.
What happens next
For the usual picture the first line is conservative, and it works for most people: physiotherapy, movement, load management and pain control, on the basis that symptoms settle even though the channel stays the same size. Where symptoms follow a nerve convincingly and have not settled, injections targeted at that level or surgery to open the channel are the options, and the scan is then read alongside an examination that localises the nerve.
Frequently asked questions
- What is foraminal stenosis?
- Narrowing of the channel through which a nerve root leaves the spine. It results from the ordinary changes of ageing — disc bulging, facet wear and bone spurs — and is graded by how much the channel is narrowed.
- Does foraminal narrowing always cause symptoms?
- No, and it very often does not. It is found frequently in people with no pain at all. What matters is whether the symptoms follow the nerve that exits at that specific level.
- Can the channel be widened without surgery?
- The bony channel itself does not change with conservative treatment, but symptoms frequently settle anyway — through reduced inflammation around the nerve, better movement and stronger supporting muscles. That is why treatment aims at symptoms rather than at the measurement.
Other words on the same report
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