Automated volumetrics of brain MRI is not the only, or even theoretically the most sensitive, method for defining abnormalities seen in AD, bvFTD, or TBI. Other MRI sequences exist and can be used clinically, including perfusion MRI with arterial spin labeling (ASL), diffusion tensor imaging (DTI), MR spectroscopy, and quantification and spatial characterization of fluid-attenuated inversion recovery (FLAIR) hyperintensities and microbleeds on susceptibility sensitive sequences. Those methods are outside the scope of this review. Here, we focus on automated volumetric software that can compute brain volumes and cortical thickness from MRI, including several programs approved by the Food and Drug Administration (FDA) for clinical purposes or otherwise used for research (Table).
Figure. Longitudinal Volumetric Quantification With NeuroReader From Brain MRI in a Person with Alzheimer Disease Dementia. This figure shows reduced hippocampal volume over the course of 6 years as seen on progressive volumetric analysis (top row) and also coronal MRI evaluations (bottom row; arrows). Progressive volume loss in the mesial temporal lobe on MRI is a characteristic imaging feature of AD.