White matter hyperintensity
Also known as: WMH, leukoaraiosis, white matter lesions
Bright spots in deep white matter on certain MRI sequences — markers of small vessel disease and accumulated cerebrovascular injury.
White matter hyperintensities (WMH) are bright spots in the brain's deep white matter visible on T2-weighted or FLAIR MRI sequences. They reflect microstructural damage — often from small-vessel disease, ischaemia, or demyelination — and accumulate with age.
In older adults they are extremely common: by age 70, most people have at least some WMH visible on MRI.
What they signal
WMH burden — total volume of these lesions — is associated with:
- Cognitive decline, particularly in processing speed and executive function
- Increased stroke risk
- Higher likelihood of progression to dementia
- Hypertension, diabetes, and other vascular risk factors
How they're measured
Quantifying WMH used to be a manual, painstaking job done by neuroradiologists. Modern automated tools can segment and measure WMH from a FLAIR scan in minutes:
- Total WMH volume (mm³)
- Periventricular vs. deep WMH burden
- Fazekas scale (0–3) for clinical reporting
WMH segmentation is part of our lesion and atrophy quantification service.
A note on terminology
Older literature uses leukoaraiosis for the same phenomenon. WMH is the modern preferred term and what you'll see in most current research.
Related terms