Automated hippocampal segmentation by regional fluid registration of serial MRI: Validation and application in Alzheimer's disease

Abstract

Voxel-level three-dimensional fluid registration was used to propagate hippocampal segmentation from baseline MR scans onto follow-up scans. In this way automated measurements of hippocampal volume and volume changes were derived. The objective was to compare this technique with the current gold standard of manual segmentation. Serial measurements were performed on 15 normal controls and 12 Alzheimer.s disease (AD) subjects. Hippocampal regions on the rigidly-registered repeat scans were generated both by manual segmentation and fluid registration. There was no significant difference between the repeat volumes generated by the two methods (p<0.001), with the mean absolute volume difference being 4.6%. Fluid registration is fully automated and has the potential to track longitudinal structural changes in the hippocampus with application to clinical trials in which large numbers of subjects require serial MR measurements.