MRI OF ACUTE CEREBRAL INFARCTION - A COMPARISON OF FLAIR AND T2-WEIGHTED FAST SPIN-ECHO IMAGING

Fluid-attenuated inversion-recovery (FLAIR) sequences have been report ed to provide high sensitivity to a wide range of central nervous syst em diseases. To our knowledge, however, FLAIR sequences have not been used to study patients with acute cerebral infarcts. We evaluated the usefulness of FLAIR sequences in this context. FLAIR sequences were ac quired on a 0.5 T superconducting unit within 8 h of the onset in 19 p atients (aged 26-80 years) with a total of 23 ischaemic lesions. The i mages were reviewed retrospectively by three neuroradiologists, and th e FLAIR images were compared with T2-weighted fast spin-echo images. A ll but one of the ischaemic lesions involving grey matter was clearly demonstrated on FLAIR images as increased signal intensity in cortical or central grey matter. FLAIR images were particularly useful for det ecting the hyperacute cortical infarcts within 3 h of onset, which wer e not readily detected on the spin-echo images. In 9 of 11 patients wi th complete proximal occlusion, the distal portion of the cerebral art ery was visible as an area of high signal intensity on FLAIR images.