Spine MRI Terms Explained: A Patient's Guide
Updated: 4 days ago
Spine MRI reports often use words like "disc bulge," "stenosis," and "foraminal narrowing." This guide explains the most common spine MRI terms in plain language, so you can follow your report and ask your doctor clear questions. Your doctor is still the best person to explain what your own results mean.
What is in a spine MRI report?
An MRI uses a strong magnet and radio waves, not X-rays, to make detailed pictures of the spine. It shows the bones, discs, spinal cord, nerves, and soft tissue. A radiologist, a doctor trained to read medical images, studies the pictures and writes a report for your doctor.
Most spine reports include:
Exam: which part of the spine was scanned, such as "MRI lumbar spine without contrast"
History or indication: why the scan was ordered, such as low back pain with leg pain
Technique: how the images were taken
Findings: what the radiologist saw, often listed level by level
Impression: a short summary of the most important findings
Start with the impression. Then read the findings with this guide nearby. For a general overview of report sections, see how to read your radiology report.
How spine levels are named
Spine reports describe findings by level. The spine has three main sections that are usually scanned:
Cervical spine (C1 to C7): the neck
Thoracic spine (T1 to T12): the upper and middle back
Lumbar spine (L1 to L5): the lower back
Below the lumbar spine is the sacrum (S1). A level such as "L4-L5" means the disc and joints between the 4th and 5th lumbar bones. "L5-S1" is the level between the lowest lumbar bone and the sacrum.
Common terms in spine MRI reports
Anatomy terms
Vertebrae: The bones that stack up to form the spine. One bone is a vertebra.
Intervertebral disc: The cushion between two vertebrae. Each disc has a tough outer ring (the annulus) and a softer center (the nucleus).
Spinal canal: The tunnel through the vertebrae that holds and protects the spinal cord and nerves.
Spinal cord: The bundle of nerves that carries signals between the brain and the body. In most adults, it ends near the top of the lumbar spine.
Nerve roots: Nerves that branch off from the spinal cord and leave the spine to go to the arms, legs, and body.
Neural foramen: The small opening on each side of the spine where a nerve root exits. More than one are called foramina.
Facet joints: Small joints at the back of the spine that connect one vertebra to the next and guide movement.
Ligamentum flavum: A ligament along the back of the spinal canal. When it thickens, it can add to narrowing of the canal.
Disc terms
Disc degeneration: Wear-and-tear changes in a disc, often with age.
Disc desiccation: The disc has lost some of its water. It looks darker on certain images. This is a common sign of disc aging.
Loss of disc height: The disc is thinner than normal, often from degeneration.
Disc bulge: The disc extends evenly past the edges of the bones around a wide area. Bulges are a common finding.
Disc protrusion: A type of herniation where disc material pushes out in a more focused area, but the base stays wider than the part pushing out.
Disc extrusion: A type of herniation where disc material pushes farther out, and the part pushing out is wider than its base.
Annular fissure (annular tear): A crack in the outer ring of the disc. It is a common finding and is not the same as an injury from a single event.
Narrowing terms
Stenosis: Narrowing of a space where nerves travel. Reports may grade it as mild, moderate, or severe.
Central canal stenosis: Narrowing of the main spinal canal.
Foraminal stenosis (foraminal narrowing): Narrowing of the opening where a nerve root exits the spine.
Lateral recess stenosis: Narrowing of the side area of the canal, just before the foramen.
Nerve root contact or compression: The report may say a disc or bone "contacts," "displaces," or "compresses" a nerve root. These words describe how much the nerve is touched or pushed.
Common spine conditions on MRI
Herniated disc
A herniated disc happens when part of the soft center of a disc pushes out through the outer ring. Reports may use the terms protrusion or extrusion to describe its shape. The report will usually list the level, the direction (such as central or to one side), and whether it touches a nerve. A herniated disc may or may not cause symptoms.
Spinal stenosis
Spinal stenosis means the canal or foramina are narrowed. It can come from disc bulges, bone spurs, thickened ligaments, or facet joint arthritis. When stenosis is present, the report usually says where it is and how severe it looks.
Spondylosis
Spondylosis is a general term for age-related wear changes in the spine. It can include disc degeneration, bone spurs (osteophytes), and facet joint arthritis (facet arthropathy). These changes are very common as people get older.
Spondylolisthesis
Spondylolisthesis means one vertebra has slipped forward compared with the one below it. Reports often grade the slip from 1 to 4 based on how far it has moved, with grade 1 being the mildest. A related term, spondylolysis, means a crack or defect in a small part of the vertebra called the pars interarticularis.
Myelopathy and radiculopathy
These words describe symptoms and nerve problems, and your doctor diagnoses them using your exam along with the MRI.
Myelopathy: a problem with the spinal cord, often from pressure on the cord. It can cause weakness, numbness, clumsy hands, or balance trouble.
Radiculopathy: irritation or pressure on a nerve root. It can cause pain, numbness, tingling, or weakness that travels down an arm or leg.
On MRI, the radiologist may note changes in the spinal cord signal, sometimes called myelomalacia or cord edema, or describe which nerve root is affected.
Other terms you might see
Modic changes: Changes in the bone right next to a disc, often seen with disc degeneration. They are labeled Type 1, 2, or 3.
Schmorl's node: A small spot where disc material has pushed into the bone above or below it. It is often found by chance.
Hemangioma: A small, harmless cluster of blood vessels inside a vertebra. It is a common finding.
Compression fracture: A vertebra that has partly collapsed. MRI can help show whether it looks new or old.
Incidental finding: Something the radiologist noticed that is not related to why the scan was done. Your doctor will tell you if it needs follow-up.
Words that sound scary but may be common
Disc bulges, disc desiccation, and mild degeneration show up often, even in people without back pain, and become more common with age. A finding on your MRI may not be the cause of your symptoms. That is why your doctor looks at the MRI together with your exam and history. The phrase "clinical correlation recommended" means the radiologist wants your doctor to compare the images with your symptoms. It is not a warning on its own. Read more in our guide to decoding the language of MRI reports.
How to use this information
Before your follow-up visit:
Read the impression and note the levels listed, such as L4-L5
Write down any words you don't understand
Ask your doctor which findings may match your symptoms
Ask what your options and next steps are
If you want to know more about the scan itself, see our comprehensive guide to spine MRIs.
Frequently asked questions
What does disc desiccation mean?
It means a disc has lost some of its water and looks darker on certain MRI images. It is a common sign of disc aging and often shows up with other wear changes.
Is a disc bulge the same as a herniated disc?
No. A bulge spreads evenly over a wide area of the disc edge. A herniation is a more focused push of disc material through the outer ring. Both are common findings, and neither always causes pain.
What is the difference between spondylosis and spondylolisthesis?
Spondylosis means general wear-and-tear changes in the spine. Spondylolisthesis means one vertebra has slipped forward over the one below it.
Is radiculopathy the same as sciatica?
Sciatica is a common name for pain that runs down the back of the leg, often from irritation of a lower lumbar nerve root. Radiculopathy is a broader term for a pinched or irritated nerve root anywhere in the spine.
What does foraminal narrowing mean?
It means the opening where a nerve root leaves the spine is smaller than normal. The report may grade it as mild, moderate, or severe.
Who should explain my spine MRI results?
The doctor who ordered your MRI. They can connect the findings to your symptoms and explain your options.
Related reading
Schedule an MRI at Millenium MRI
If your doctor has ordered a spine MRI, Millenium MRI can help. Our scans are read by board-certified radiologists and performed by ARRT-certified technologists. Results are usually sent to your referring doctor within 24 hours, and same-day appointments are often available. We accept most insurance plans, workers' compensation, personal injury cases, and self-pay. We have centers in Ocala, Largo, and Tamarac, Florida, and in North Little Rock, Springdale, Jonesboro, and Marion, Arkansas, open Monday through Friday, 9am to 5pm.
This article is for general information and is not medical advice. Talk with your doctor about your specific situation.
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