The authors observed in healthy subjects foci of non-homogeneous signal intensity in the FLAIR sequence (Flow Attenuated Inversion Recovery) in the white matter of the brain. The foci were detected in the pyramidal pathway, in the brain ventricles and their vicinity. These non-homoge- neous features of white matter were already described in T2W pictures, however they were much more diffuse and less contrasting. There are no unequivocal criteria which indicate in a focus with increased signal whether pathological or physiological changes are involved. In the interpretation of findings we must take all these facts into consideration and select an individual procedure. We always compare pictures in the FLAIR modus with those in T2W (Turbo SE). In controversial cases the patient is examined in PDW images.

        Key words: magnetic resonance imaging - Flow Attenuated Inversion Recovery (FLAIR) - multiple sclerosis (MS) - cerebral ischaemia