Differentiation of recent and old cerebral infarcts by diffusion-weighted MRI

We performed MRI, including diffusion-weighted imaging, in 15 patients with recurrent strokes with acute ischaemia and at least one old lesion accordi ng to the clinical history and/or CT. Routine MRI showed similar signal int ensity changes in both situations. Diffusion-weighted images, however were positive in all acute or subacute infarcts. The high signal of acutely dist urbed diffusion due to intracellular oedema could also be identified in sma ll brain stem lesions. Spatial resolution was increased by applying separat e gradients in each axis instead of creating anisotropy-independent trace i mages.