MR measurement of regional relative cerebral blood volume in epilepsy

The purpose of this study was to evaluate the utility of magnetic resonance (MR) relative cerebral blood volume (rCBV) maps for studying regional hemo dynamic changes in interictal and ictal epilepsy patients, Ten epilepsy pat ients were examined on a 1.5 T MR system. Nine patients were investigated i nterictally and one patient ictally, In the nine interictal patients, the d ynamic plane was defined coronally through the hippocampus symmetrically, F or the ictal patient, an axial dynamic plane was defined and the patient wa s scanned during seizure, Positron emission tomography (PET) studies were p erformed in 8 of the 10 patients, Lower rCBV of the left hippocampus was pr edicted by rCBV maps in seven of the nine interictal patients, The mean rat ios of rCBV were 1.96 for left hippocampus/white matter and 2.49 for right hippocampus/white matter The difference between these two ratios is statist ically significant (P = 0.01, t-test), In two of the nine interictal tempor al lobe epilepsy patients, lower rCBV areas were observed in the right hipp ocampus. In the ictal patient, the regional rCBV map demonstrated increased blood volume in the lesions, In eight of eight patients who underwent PET studies, MR rCBV findings were consistent with PET findings. The results sh ow that regional hemodynamic changes in epilepsy can be evaluated with dyna mic contrast-enhanced MR imaging. MR rCBV maps are sensitive to characteriz e seizure foci both ictally and interictally, (C) 1999 Wiley-Liss, Inc.