Spine & MRI Glossary: Disc, Nerve & Treatment Terms Explained

Jump to: Vertebra · Cervical, thoracic, lumbar · Sacrum · Intervertebral disc · Annulus fibrosus · Nucleus pulposus · Facet joint · Foramen · Nerve root · Cauda equina · Disc bulge · Herniated disc · Protrusion · Extrusion · Sequestration · Annular fissure · Disc desiccation · Degenerative disc disease · Modic changes · Radiculopathy · Sciatica · Spinal stenosis · Foraminal stenosis · Neurogenic claudication · Myelopathy · Cauda equina syndrome · Spondylolisthesis · Spondylolysis (pars defect) · Spondylosis · Osteophyte · Paresthesia · Non-surgical spinal decompression · Traction · Surgical decompression · Microdiscectomy · Laminectomy · Spinal fusion · Epidural steroid injection · Spinal manipulation · MRI · Straight-leg raise · Thecal sac · Red flags

What are the parts of the spine called?

The basic anatomy words that show up on reports and in exam notes.

Vertebra: One of the bones stacked to form the spine. Plural: vertebrae.
Cervical, thoracic, lumbar: The neck (C1 to C7), mid-back (T1 to T12) and low back (L1 to L5) regions of the spine. Reports name a level by the vertebrae around it, such as L4-L5.
Sacrum: The triangle-shaped bone below the lumbar spine, labeled S1 at the top. L5-S1 is the lowest lumbar disc.
Intervertebral disc: The cushion between two vertebrae. It has a tough outer ring and a gel-like center.
Annulus fibrosus: The tough outer ring of a disc.
Nucleus pulposus: The soft, gel-like center of a disc. In a herniation, some of it pushes through the annulus.
Facet joint: A small paired joint at the back of each spinal level that guides movement. Facet joint pain.
Foramen: The opening on each side of the spine where a nerve root exits. Plural: foramina.
Nerve root: The part of a spinal nerve as it leaves the spinal canal. Pressure or irritation here can cause pain, numbness or weakness in an arm or leg.
Cauda equina: The bundle of nerve roots at the bottom of the spinal canal, below the end of the spinal cord.

What do disc findings mean?

Shape and condition words used on MRI reports, following standard radiology nomenclature (Fardon et al.).

Disc bulge: Disc tissue extending beyond its normal edge over a broad area, more than a quarter of its circumference. Very common with age. Bulging disc.
Herniated disc: Localized displacement of disc material beyond its normal edge. Protrusion, extrusion and sequestration are types. Herniated disc.
Protrusion: A herniation whose base is wider than the distance it extends. Protrusion vs. extrusion.
Extrusion: A herniation where the displaced material is wider than its base, or extends above or below the disc level.
Sequestration: An extruded piece of disc that has separated from the parent disc.
Annular fissure: A crack in the annulus. Often called an annular tear. Frequently found in people without pain. Annular tear.
Disc desiccation: Loss of water in the disc, seen as a darker disc on certain MRI images. A normal part of aging.
Degenerative disc disease: Age-related wear in a disc, such as drying out, loss of height and small tears. Despite the name, it is not a disease in the usual sense. Degenerative disc.
Modic changes: Changes in the bone next to a disc seen on MRI, usually linked to degeneration.

What are the common spine conditions?

Diagnoses you may hear from a provider.

Radiculopathy: Symptoms from an irritated or compressed nerve root: pain, numbness, tingling or weakness along that nerve's path. Pinched nerve.
Sciatica: Pain, tingling or numbness that travels from the low back or buttock down the leg along the sciatic nerve, often from a herniated disc (MedlinePlus). Sciatica.
Spinal stenosis: Narrowing of the spinal canal or foramina that can squeeze the spinal cord or nerve roots. Spinal stenosis.
Foraminal stenosis: Narrowing of a foramen, which can pinch the exiting nerve root.
Neurogenic claudication: Leg pain, heaviness or tingling brought on by standing or walking and eased by sitting or bending forward. A common stenosis symptom.
Myelopathy: Compression of the spinal cord itself, usually in the neck. Signs include clumsy hands, trouble with fine motor tasks and balance problems (AAOS). Needs prompt medical evaluation. Arm pain and numbness.
Cauda equina syndrome: Severe compression of the cauda equina. Warning signs include numbness in the groin or inner thighs and new bladder or bowel problems. It is an emergency (Cleveland Clinic).
Spondylolisthesis: One vertebra slipped forward on the one below it. Spondylolisthesis.
Spondylolysis (pars defect): A stress fracture in a small part of the vertebra called the pars interarticularis. It can lead to spondylolisthesis.
Spondylosis: General age-related wear in the spine's discs and joints.
Osteophyte: A bone spur. Common with arthritis of the spine.
Paresthesia: Tingling, pins and needles, or a crawling feeling in the skin. Leg numbness and tingling.

What do the treatment terms mean?

Surgical and non-surgical options you may be comparing.

Non-surgical spinal decompression: A form of motorized traction on a computer-controlled table that gently stretches the spine in cycles. Research is limited and results vary. Spinal decompression.
Traction: Pulling force applied to the spine, manually or with a device. Cochrane found no clear benefit over sham or other treatments for low back pain. Decompression vs. traction.
Surgical decompression: Surgery that removes bone or disc tissue pressing on nerves, such as a laminectomy or discectomy. Different from non-surgical decompression. Decompression vs. surgery.
Microdiscectomy: Surgery through a small incision to remove the herniated part of a disc pressing on a nerve. The most common operation for a single herniated disc (AAOS).
Laminectomy: Surgery that removes part of the back of a vertebra (the lamina) to make room for nerves, often for stenosis.
Spinal fusion: Surgery that joins two or more vertebrae so they heal into one bone. Hardware or a recent fusion usually rules out decompression.
Epidural steroid injection: An injection of steroid medicine near irritated nerve roots to reduce inflammation and pain. Decompression vs. injections.
Spinal manipulation: A hands-on chiropractic adjustment that moves a joint quickly within or slightly beyond its usual range. Decompression vs. adjustment.

What do the exam and imaging terms mean?

Words from the exam room and the imaging center.

MRI: Magnetic resonance imaging. Shows discs, nerves and soft tissue without radiation. Often finds age-related changes that are not causing pain (MedlinePlus). How to read your MRI report.
Straight-leg raise: An exam test: lying on your back, the provider lifts your straight leg. Pain that shoots down the leg may point to sciatica (MedlinePlus).
Thecal sac: The fluid-filled sleeve around the spinal cord and nerve roots. "Effacement" means it is being pressed on.
Red flags: Symptoms that suggest a serious cause and need prompt medical care, such as fever, a history of cancer, major injury, or bladder or bowel changes. When to see a doctor.

Can someone explain my own report?

Yes. Springville Disc Center in Springville offers a free MRI review.

Dr. Gordon Stapel, DC, in practice since 1993, can walk through your report and images and explain which findings may relate to your symptoms. Call (801) 491-8688 or see the free MRI review page.

Glossary FAQs

What is the difference between a bulging and a herniated disc?

A bulge involves a broad part of the disc edge and is very common with age. A herniation is a more localized push of disc material beyond its normal edge.

Is non-surgical spinal decompression the same as decompression surgery?

No. Non-surgical decompression is motorized traction on a table. Surgical decompression removes bone or disc tissue pressing on nerves.

Is degenerative disc disease a disease?

Not in the usual sense. It describes age-related wear in the discs, which many people have without pain.

Which terms on an MRI report need prompt attention?

Findings the radiologist flags for follow-up, spinal cord compression or signal change, and anything suggesting infection, fracture or a mass. Ask the provider who ordered the scan.

Talk with Dr. Stapel about your pain

Call the office or request a free consultation. You'll talk through your symptoms and history, and you'll get an honest answer about whether spinal decompression is worth considering for you.

Call (801) 491-8688 Request a Free Consultation

The consultation is free, with no obligation to start treatment. Have an MRI? Ask about the free MRI review.

Sources

This website is operated for Stapel Family Chiropractic (Springville Disc Center) in Springville, Utah. Care is provided by Dr. Gordon Stapel, DC, a licensed chiropractic physician. About this site.