Common MRI Report Terms Explained

MRI reports have a vocabulary of their own. A CT report talks about things being dense or low-density, because CT measures how much X-ray passes through tissue. MRI measures something different — how water and fat in tissue behave in a magnetic field — so its reports talk about signal, sequences and intensity. Most of the words that worry people on an MRI report are descriptions of how something looked on one of those sequences, not diagnoses.

This guide goes through the terms you are most likely to meet, grouped by where they appear. Each one links to a fuller page explaining what it means and, just as importantly, what it does not mean.

Words about how the scan was done

These usually appear in the Technique section near the top.

Sequences: T1, T2, FLAIR and DWI

An MRI scan is made up of several "sequences", each a different way of setting up the scanner so that different tissues stand out.

• T1-weighted images are good for anatomy. Fat looks bright; fluid looks dark.
• T2-weighted images are good for showing water. Fluid looks bright, which is why so many abnormal-sounding findings are "T2 bright".
• FLAIR is a T2-type sequence that darkens normal brain fluid so small changes in brain tissue stand out.
• Diffusion-weighted imaging (DWI) shows how freely water moves, and is the standard way to look for a recent stroke.

With and without contrast

"Post-contrast" or "with gadolinium" means a contrast agent was injected and extra images were taken afterwards. It is a routine part of many scans and does not mean something suspicious was expected. See contrast.

Limited study, motion artifact

If you moved, could not lie flat, or have metal nearby, the images may be less detailed. The radiologist will say so with words like limited study or motion-degraded. These describe the pictures, not you. An artifact is something on the image caused by the scanning process, not by your anatomy.

Words about brightness (signal)

This is the part of MRI vocabulary that confuses people most.

• Hyperintense / hyperintensity — brighter than the surrounding tissue on that sequence. See hyperintense and the fuller explanation of T2 hyperintensity.
• Hypointense — darker than the surrounding tissue. See hypointense.
• Isointense — about the same brightness as the tissue around it.
• Heterogeneous — uneven or mixed in appearance. See heterogeneous.
• Punctate — tiny, dot-like. See punctate.

The key point: brightness on its own is not a diagnosis. Water is bright on T2, so anything that holds a little more water than its surroundings — inflammation, a cyst, a bruise, an old scar, normal ageing — can be "hyperintense". The radiologist reads the same spot across several sequences before deciding what it most likely is, and that conclusion goes in the Impression.

Words from brain MRI reports

• No restricted diffusion — no sign of a recent stroke on DWI. One of the most common reassuring sentences on a brain MRI.
• Small vessel ischemic changes — small bright spots in the white matter, very common with age, high blood pressure and other vascular risk factors.
• Age-related volume loss — the brain looks the way brains usually do at that age. It is not a diagnosis of dementia.
• No mass effect or midline shift — nothing is pressing on or pushing the brain out of position.
• Enhancing lesion — an area that took up contrast. Many causes, benign and otherwise; the pattern and the Impression carry the meaning.
• White matter and periventricular — locations, not findings.

Words from spine MRI reports

Spine MRI reports are long, level by level (L3-L4, L4-L5, L5-S1 and so on), and almost everyone over a certain age has something described. Most of it is ordinary wear.

• Degenerative disc disease and desiccation — discs that have lost some water with age.
• Disc bulge — a disc extending a little past the bone edges over a broad area. Very common in people without pain.
• Disc protrusion and extrusion — types of herniation, named by shape. What matters most is whether a nerve is touched.
• Annular tear — a small split in the outer ring of a disc. Common, often age-related.
• Modic changes — changes in the bone next to a disc, graded type 1, 2 or 3.
• Neural foraminal narrowing — the side opening a nerve leaves through is narrower than usual, graded mild to severe.
• Ligamentum flavum hypertrophy and facet joint arthropathy — thickening at the back of the canal and wear in the small joints, often contributors to stenosis.

A useful rule of thumb when reading a spine report: look for the words "contacts", "displaces" or "compresses" next to a nerve root, and for the grade of canal or foraminal narrowing. Those are the details your doctor matches to the pattern of your symptoms. A finding at a level that does not match where you feel things usually is not the explanation.

Words from joint MRI reports

• Bone marrow edema — extra fluid inside a bone, from a bruise, stress, arthritis and other causes. MRI shows it; X-rays cannot.
• Small joint effusion — a little more fluid than usual in the joint; often minor.
• Mild degenerative changes and joint space narrowing — ordinary wear of the joint surfaces.
• Osteophyte — a bony spur at the edge of a joint, part of wear and tear.

Words that appear in every MRI report

• Unremarkable — normal.
• Nonspecific — real, but the appearance does not point to one cause.
• Incidental finding — something unrelated to why you were scanned.
• Clinical correlation is recommended — the doctor who knows your symptoms needs to interpret this.
• No prior studies for comparison — there was no earlier scan to compare with.
• The Impression — the radiologist's summary, and the best place to start reading.

How to read your MRI report without panicking

1. Start with the Impression. It is the radiologist's conclusion in a few lines. The Findings section is the long, detailed description that supports it.
2. Treat signal words as descriptions. "Hyperintense", "enhancing" and "heterogeneous" say how something looked, not what it is.
3. Look for the qualifiers. "Mild", "age-related", "incidental" and "unchanged" all lower the stakes; "recommend" tells you there is a next step.
4. Write down your questions. The doctor who ordered the scan can put the report together with your symptoms, which the radiologist could not.

If you have a line from your report you want to look up, paste it into the box on any report phrase page or the glossary and it will pick out the terms it recognises. For more abbreviations, see our guide to common radiology abbreviations, and for the differences between scan types, MRI vs CT.

If you would rather have your whole report explained in one place, you can upload it to Radily for a plain-English explanation of what it says.

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This guide explains how terms are commonly used in MRI reports. It is general information, not a diagnosis and not medical advice. Only your doctor can tell you what your own report means for you.