An automated method for extracting brain volumes from three commonly acquir
ed three-dimensional (3D) MR images (proton density, T1 weighted, and T2-we
ighted) of the human head is described. The procedure is divided into four
levels: preprocessing, segmentation, scalp removal, and postprocessing. A u
ser-provided reference point is the sole operator-dependent input required,
The method's parameters were first optimized and then fixed and applied to
30 repeat data sets from 15 normal older adult subjects to investigate its
reproducibility. Percent differences between total brain volumes (TBVs) fo
r the subjects' repeated data sets ranged from .5% to 2.2%. We conclude tha
t the method is both robust and reproducible and has the potential for wide
application.