White matter hyperintensities: Meaning in a Radiology Report

Also written as: white matter lesions, white matter changes, FLAIR hyperintensities, leukoaraiosis

White matter hyperintensities are bright spots or patches in the brain's wiring (the white matter) on MRI. They are very common, especially with age.

What it means

White matter is the brain's wiring: bundles of nerve fibers that link one area to another. On T2 and FLAIR MRI images, spots where the tissue holds a little extra water look brighter than their surroundings. Most often they reflect wear in the tiny blood vessels that feed the white matter. The term describes how the spots look, not one particular disease.

When it matters

A few small spots are very common after middle age, especially with high blood pressure, diabetes, smoking or migraine. Radiologists often grade them on the Fazekas scale, from 0 (none) to 3 (large merged areas). More extensive changes are linked over time to a higher risk of stroke and memory problems. That is why doctors often focus on blood pressure and other risk factors. Spots with an unusual shape or location may prompt tests for conditions such as multiple sclerosis.

Questions to ask your doctor

What Fazekas grade are these spots, and is that usual for my age?
Could my blood pressure, blood sugar or cholesterol be playing a part?
Does the pattern fit small vessel change, or something like MS?

General information, not medical advice. What a finding means for you depends on your symptoms, your history and the images themselves, so talk your results through with a doctor.