Degenerative Disc Disease on MRI: Imaging Findings

What Is Degenerative Disc Disease?

Modic Changes on a Spine MRI: Type 1, 2 and 3

Modic changes are changes in the bone marrow right next to a worn disc, where the disc meets the vertebra, and they are seen only on MRI. Type 1 looks like edema with inflammation, type 2 like fat replacing the marrow, and type 3 like hardened bone. They belong to disc degeneration, not to a separate disease.

How Modic changes appear in a report

• “Modic type 1 endplate changes at L5–S1”
• “Type 2 degenerative endplate changes at L4–L5”
• “Mixed Modic type 1/2 changes”
• “Endplate marrow edema adjacent to a degenerated disc”

Type 1, type 2 and type 3 compared

In the study that named them, type 1 was dark on T1 and bright on T2 images, and tissue samples showed fissured endplates with vascular fibrous tissue. Type 2 was bright on T1, matching fatty yellow marrow. When followed over time, type 1 turned into type 2 within 14 months to 3 years in five of six patients, while type 2 stayed stable. Type 3, dark on both, reflects sclerosis of the bone.

Do Modic changes cause back pain?

They are linked to it but do not prove it. A systematic review found Modic changes in a median of 43% of people with low back pain or sciatica and 6% of people in non-clinical groups, with an association to pain in seven of ten studies, yet some people with them have no pain. Antibiotics aimed at the finding have not held up: in a randomised trial, three months of the antibiotic amoxicillin gave no clinically important benefit over placebo for chronic back pain with Modic changes and caused more side effects.

Questions to ask about Modic changes

• Which Modic type is it, and next to which disc?
• Does that level match where my back hurts?
• Has it changed since my previous MRI?
• Which treatments do you suggest, and how strong is the evidence for them?

Annular Fissure or Annular Tear: What the Finding Means

An annular fissure is a split between the layers of fibres in the annulus, the tough outer ring of a disc. The shared spine nomenclature prefers “fissure” to “annular tear”, because the change is usually part of disc ageing rather than a sign of injury. On MRI it can show as a small bright spot called a high-intensity zone.

Ways a report can describe it

• “Posterior annular fissure at L4–L5”
• “Small posterior annular tear”
• “High-intensity zone (HIZ) in the posterior annulus”
• “Annular fissure with a small central disc protrusion”

Fissure, tear or herniation?

A fissure on its own is not a herniation. If disc material has pushed through it beyond the edge of the disc, the report names that separately as a protrusion or an extrusion, explained on the herniated disc page. Fissures are also frequent without symptoms: a review of pain-free adults found them in 19% of 20-year-olds and 29% of 80-year-olds, so the finding is weighed together with your symptoms and examination rather than treated on its own.

What to ask about an annular fissure

• Is the fissure on its own, or is there a protrusion at the same level?
• Does the report suggest a recent injury, or ageing of the disc?
• Is this level likely to be connected with my pain?