Fully-Automated Quantification of Regional Brain Volumes for Improved Detection of Focal Atrophy in Alzheimer Disease

SUMMARY: Volumetric analysis of structural MR images of the brain may provide quantitative evi-dence of neurodegeneration and help identify patients at risk for rapid clinical deterioration. This note describes tests of a fully automated MR imaging postprocessing system for volumetric analysis of structures (such as the hippocampus) known to be affected in early Alzheimer disease (AD). The system yielded results that correlated highly with independent computer-aided manual segmentation and were sensitive to the anatomic atrophy characteristic of mild AD. It is well established that Alzheimer disease (AD) and relatedneurodegenerative disorders are associated with atrophy in the brain that can be reliably detected with quantitative anal-ysis ofMR images. Consistent with histologic findings,1 quan-tification of structural MR images can reveal significant atro-phy in medial temporal lobe structures.2 Such loss of tissue is typically accompanied by increases in ventricular volume, particularly in the inferior portion of the lateral ventricle. Quantitative MR imaging may also aid in the detection of AD-related neuropathologic disorders at the prodroma