Regarding the article by Stroman et al1 published in the February issue of the Archives, my first concern is whether we can confidently diagnose cerebral ischemia based on magnetic resonance imaging (MRI) alone, as the authors seem to do. When one has ruled out specific causes for white matter lesions in an elderly population, as presented in this study, one is probably left with infarction, ischemia without infarction, and aging changes that may not be ischemic.
While we can probably ascribe a large white matter lesion to cerebral ischemia when it correlates with deficits in positron emission tomography F18 fluoromethane scans,2 correlation with other studies such as neuropsychological testing,3 histopathologic studies,4 and dementia studies5 is tentative at best. Relying then on MRI alone is suspect. The total cross-sectional area of white matter lesions may be the best way to infer ischemia, whether subcortical or deep,