MAGNETIC-RESONANCE-IMAGING IN PARTIAL EPILEPSY - ADDITIONAL ABNORMALITIES SHOWN WITH THE FLUID ATTENUATED INVERSION-RECOVERY (FLAIR) PULSE SEQUENCE

Thirty six patients with a history of partial epilepsy had A IRI of th e brain performed with conventional T1 and T2 weighted pulse sequences as well as the fluid attenuated inversion recovery (FLAIR) sequence. Abnormalities were found in 20 cases (56%), in whom there were 25 lesi ons or groups of lesions. Twenty four of these lesions were more consp icuous with the FLAIR sequence than with any of the conventional seque nces. In 11 of these 20 cases, lesions thought to be of aetiological i mportance were only seen with the FLAIR sequence. In eight this was a solitary lesion. In the other three, an additional and apparently sign ificant lesion (or lesions) was only seen with the FLAIR sequence when another lesion had been identified with both conventional and FLAIR s equences. The 11 additional lesions or groups of lesions were seen in the hippocampus, amygdala, cortex, or subcortical and periventricular regions. No lesion was found with any pulse sequence in 16 (44%) of th e original group of 36 patients. In the eight cases where a lesion was seen only with the FLAIR sequence, localisation was concordant with t he electroclinical features. Two of the eight patients with solitary l esions seen only on the FLAIR sequence underwent surgery, after which there was pathological confirmation of the abnormality identified with imaging. In one patient with a congenital cavernoma, the primary lesi on was best seen with a contrast enhanced T1 weighted spin echo sequen ce. In this selected series, the FLAIR sequence increased the yield of MRI examinations of the brain by 30%.