Glossary

10 Common Radiology Terms Explained in Plain English

8 min readMarch 24, 2026Written by a Board-Certified Radiologist

From 'T2 hyperintensity' to 'mild degenerative changes' — here are the 10 most confusing radiology terms explained simply by a board-certified radiologist.

The 10 Most Confusing Radiology Terms — Explained

Radiology reports are written for physicians, not patients. Here are the 10 terms that cause the most confusion, explained in plain English by a board-certified radiologist.


1. Unremarkable

Despite sounding negative, "unremarkable" in radiology means normal. A radiologist who writes "the liver is unremarkable" means the liver looks completely normal — nothing worth remarking on.


2. Mild Degenerative Changes

This refers to normal wear-and-tear that occurs with aging. It is extremely common, especially in the spine and joints. Think of it like wrinkles on the inside of your body — expected and not necessarily causing symptoms.


3. T2 Hyperintensity

On an MRI, T2-weighted images show fluid as bright white. A "T2 hyperintensity" is an area that appears brighter than expected. It can represent many things — inflammation, fluid, scar tissue, or normal aging — and must be interpreted in context.


4. Effusion

An effusion is a collection of fluid where it should not be. A "knee effusion" means there is excess fluid in the knee joint. A "pleural effusion" means fluid around the lung.


5. Atelectasis

This refers to partial collapse or incomplete inflation of a portion of the lung. It is very common and often seen in patients who have been lying down for extended periods. It is usually not serious.


6. Lesion

A lesion is simply an area of abnormal tissue. It is a descriptive term, not a diagnosis. A lesion could be benign (harmless) or require further evaluation. The radiologist will usually characterize it further.


7. Heterogeneous

This means not uniform in appearance — the tissue or organ has varying densities or signals. It can be normal or abnormal depending on the context.


8. Cortical Irregularity

The cortex is the outer layer of bone. A cortical irregularity means the surface of the bone appears uneven. This can be a normal variant, a healing fracture, or something requiring follow-up.


9. Incidental Finding

An incidental finding is something the radiologist noticed that was not the reason for the scan. For example, a small kidney cyst found on an abdominal CT ordered for stomach pain. These are often benign but may require follow-up.


10. No Evidence Of

When a radiologist writes "no evidence of [condition]," they mean they did not see signs of that condition on the images. For example, "no evidence of pulmonary embolism" means no blood clot was seen in the lung arteries.


*Still confused by a term in your specific report? Use ClearScan AI to get a personalized plain-English translation.*

*This article was written by a board-certified radiologist with over 20 years of clinical experience.*

Written by a Board-Certified Radiologist

This article was reviewed and written by a board-certified radiologist, Medical Director, and Radiation Safety Officer with over 20 years of clinical experience. It is intended for patient education only and does not constitute medical advice.

Medical Disclaimer: This article is for educational purposes only. Always consult your physician or healthcare provider regarding your specific radiology results and medical condition.

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