Study on hippocampal volume with quantitative 3T magnetic resonance imaging in Chinese patients with epilepsy

Background  It was still rare for the quantitative magnetic resonance imaging (MRI) research of regional changes in hippocampus sclerosis (HS) in Chinese patients with epilepsy. This study aimed to study the hippocampal volumes (HVs) with quantitative MRI measurement in Chinese patients with epilepsy.

Methods  Forty-six Chinese patients with epilepsy (intractable epilepsy (IE), n=21; non-intractable epilepsy (NIE), n=25) and 25 normal controls were collected between July 2007 and March 2008. All of the subjects underwent a 3T high-resolution MRI with oblique coronal thin sections oriented perpendicular to the hippocampal long axis. Hippocampal structures were assessed by visual detection, and HVs were quantitatively studied with a Picture Archiving and Communication System (PACS).

Results  Our study suggested that there was no significant difference in gender (P >0.05) while the right hippocampal head volume (HHV), hippocampal body volume (HBV), and the whole hippocampal volume (HCV) were greater than the left one (P <0.05), but no significant difference was found in bilateral hippocampal tail volume (HTV) (P >0.05) in normal controls. That unilateral/diffuse (64%/21%) and bilateral/focal (86%/20%) hippocampal atrophy (HA) were significant in IE and NIE patients, respectively. Anterior hippocampus, especially HHV (26% in IE and 20% in NIE) and HBV (29% in IE and 12% in NIE), had more significant atrophy than the HTV (5% in IE and 0% in NIE) in patients with epilepsy.

Conclusion  By assessing the volumes of the regional hippocampus with 3T MRI, we could better define the range and distribution of HS, since regional or subtle changes in HVs could be detected earlier with 3T MRI.