A plain-language guide to common MRI terminology found in radiology reports (no diagnosis, no interpretation).
What This Page Covers
This page explains general MRI terminology that often appears in radiology reports.
It does not interpret your personal MRI, images, symptoms, or diagnosis.✔ Easy-to-read definitions
✔ Neutral explanations
✔ No medical advice
✔ No clinical interpretation
Common MRI Terms and Their General Meaning
“Hyperintense” and “Hypointense”
These describe how bright or dark something looks on a particular MRI sequence.
• Hyperintense = brighter area
• Hypointense = darker areaThe meaning depends on the MRI sequence (T1, T2, STIR, FLAIR) and must always be interpreted by a radiologist.
T1, T2, FLAIR, STIR (MRI Sequences)
MRI uses different “sequences,” each showing tissue in a specific way.
• T1-weighted: fat appears bright; good for anatomy.
• T2-weighted: fluid/inflammation appears bright.
• FLAIR: similar to T2 but suppresses fluid to highlight abnormalities.
• STIR: suppresses fat; helpful for detecting edema or inflammation.
Contrast Enhancement
When MRI contrast is used, tissue that “enhances” becomes brighter after injection.
This describes how tissue behaves with contrast, not what the cause is.
Edema
Means excess fluid or swelling inside a tissue.
Often appears bright on T2 or STIR sequences.
Lesion
A neutral descriptive term meaning:
“An area that looks different from surrounding tissue.”
It does not indicate severity by itself.
Degenerative Changes
Describes age-related changes seen in joints or the spine, such as:
• disc dehydration
• mild disc bulging
• cartilage wearThese are extremely common and often normal over time.
Disc Bulge / Protrusion / Herniation
These terms describe the shape of a spinal disc change.
• Bulge: broad, gentle extension
• Protrusion: more focal extension
• Herniation: disc material moves beyond its normal boundaryThese words describe appearance, not severity.
Effusion
Means fluid inside a joint space (commonly the knee, shoulder, ankle).
Mass Effect
This means one structure is pushing or pressing on another.
It describes the effect, not the cause.
Artifact
An MRI artifact is image distortion caused by metal, dental fillings, motion, or technical factors.
Artifacts can hide or mimic findings.
Why MRI Reports Use Technical Language
Radiology reports are written for other doctors, not patients.
This ensures accuracy and consistency but can make the wording difficult to understand.This page helps translate terminology—but cannot interpret clinical findings.
When to Discuss Your Results With Your Doctor
Always speak with your doctor if you:
• have concerns about the findings
• want to understand the significance
• need advice or next steps
• want correlation with symptoms or examMRI terminology alone cannot provide diagnosis or treatment guidance.
Plain-Language Explanation Service
If you have trouble understanding your MRI report wording, you can request:✔ A plain-language restatement of the phrases and terminology
✘ No diagnosis
✘ No interpretation of images
✘ No medical opinionsThe goal is to help you feel more informed when discussing the results with your doctor.Understand Your Report →
Important Disclaimer
This page provides general, educational information about MRI terminology only.
It does not interpret your specific MRI, give medical advice, or diagnose any condition.Always discuss your personal report with your healthcare provider.