Does FLAIR super-resolution erase or hallucinate small white-matter lesions?
When AI sharpens brain scans, does it hide tiny disease signs?
Researchers tested whether artificial intelligence methods that enhance low-resolution brain MRI scans preserve small white-matter lesions—signs of stroke risk and neurodegeneration. The dominant problem was erasure: AI tended to delete real small lesions rather than invent fake ones, and this worsened with thicker original scans. One method, ECLARE, recovered small lesions better than others, but none performed as well as the original high-resolution images.
Brain MRI scans in hospitals are routinely too thick to catch small lesions, and doctors increasingly use AI enhancement to sharpen them. If that enhancement erases real disease signs, patients could miss early warnings of stroke or dementia. This work shows which enhancement methods are safest—and that relying blindly on sharpened scans risks overlooking small but clinically important damage.