[FLAIR images of cerebral and brain stem infarction].

FLAIR (fluid-attenuated inversion recovery) images are MR images obtained with an inversion recovery sequence having a long inversion time (TI) and a long echo time (TE). We examined 47 cases (56 graphics) of lacunar infarction (LI), 28 cases (32 graphics) of cortical infarction (CI) and 16 cases (23 graphics) of stem infarction (SI) with a FLAIR sequence having a repetitive time (TR) of 6500 msec, a TI of 1700 msec and a TE of 110 msec, and compared these graphics with T2-weighted images by spin-echo sequence (TR 2500 msec, TE 90 msec). LI and CI were better demonstrated with FLAIR images than with conventional T2-weighted images. FLAIR images were very useful in detecting lesions adjacent to the lateral ventricles and the cerebral sulci in particular, because the cerebrospinal fluid signals in the lateral ventricles and the cerebral sulci were low-intensity, with brain tissue appearing as high-intensity areas. In a number of old infarctions, FLAIR images revealed cystic structures, constructed out of internal low-intensity areas and peripheral high-intensity areas. These structural changes suggested that FLAIR images can provide information on pathological changes.