SEMIAUTOMATED EXTRACTION OF BRAIN CONTOURS FROM MRI

We compared brain volumes computed by trained operators using the BRAI N-MAP algorithm, which automatically extracts the contours of the brai n from gradient-echo magnetic resonance images, The images of 19 subje cts randomly selected from a group of normals and a group of patients with dementia were included. BRAIN-MAP found brain perimeters that wer e on the average ca. 3 % tighter than those obtained by two experience d operators. Between-operator and within-operator reproducibility of t he analyses were also estimated and found to be (-0.13 +/- 0.51) % and (-0.63 +/- 0.08) %, respectively. Replicate volume measurement by the computer alone provided a reproducibility of (0.44 +/- 0.46) %.