Foraminal stenosis: Meaning in a Radiology Report

Foraminal stenosis

Also written as: foraminal narrowing, neural foraminal stenosis, neuroforaminal narrowing, foraminal encroachment

Foraminal stenosis means one of the side openings where nerve roots leave the spine is narrowed. Reports grade it as mild, moderate or severe.

Seen on: MRI, CT

How it reads in a report

L4-L5: A disc bulge and facet hypertrophy cause moderate left foraminal stenosis, with mild impingement of the exiting left L4 nerve root.

What it means

At each level of the spine, a nerve root exits on each side through a small opening called the neural foramen. The opening can narrow when a disc bulges into it, bone spurs grow, a facet joint enlarges, or the disc loses height. On MRI, mild often means some of the fat cushioning the nerve is lost. Severe often means the nerve itself looks squeezed.

When it matters

Some foraminal narrowing is very common with age, often on both sides, and many people with it have no symptoms. It matters when the side and level match pain, tingling, numbness or weakness in the area that nerve supplies, such as one arm or leg. Doctors check this with an exam. If symptoms persist, your doctor may suggest nerve tests or a spine specialist.

Questions to ask your doctor

Which nerve root passes through the narrowed opening?
Do the side and level match my arm or leg symptoms?
Is the nerve itself pressed, or only the space around it?

General information, not medical advice. What a finding means for you depends on your symptoms, your history and the images themselves, so talk your results through with a doctor.