Mesial temporal sclerosis: Diagnosis with fluid-attenuated inversion-recovery versus spin-echo MR imaging

PURPOSE: To compare the accuracy of a fluid-attenuated inversion-recovery (FLAIR) sequence with that of a conventional double spin-echo (SE) sequence in the identification of increased signal intensity of the hippocampus in mesial temporal sclerosis (MTS). MATERIALS AND METHODS: Three blinded reviewers independently graded the FLAIR and SE images in 36 patients with intractable complex partial seizures. Reproducibility was tested. At histopathologic examination, the criterion standard, 32 patients had MTS. RESULTS: The accuracy of FLAIR images was 97% versus 91% for SE images (P < .02). The radiologists preferred the contrast properties of FLAIR to those of SE images by a significant margin (P < .0001). Surgical to nonsurgical hippocampal contrast-to-noise ratio (C/N) measurements were better for the second echo of the SE sequence than for FLAIR (P < .002). Hippocampus-to-background tissue C/N was superior with FLAIR (P < .0001). CONCLUSION: FLAIR provides images with T2-weighted contrast and complete suppression of high signal intensity of CSF. Incorporation of a FLAIR sequence into the routine MR evaluation of patients with epilepsy is recommended.