Figure 1

Representative images (a–c: of subject with %Cerebrum z-score −3.89) explain the procedure of measuring %Cerebrum, %Periventricular and %Cortical atrophy using a computer-assisted processing system. (a) An image after skull stripping. (b) Measurement of the cerebrospinal fluid space (asterisks, ventricular space; arrows, sulcal space). (c) Measurement of intracranial space. %Cerebrum atrophy=(intracranial space−cerebrospinal fluid space)/intracranial space × 100 (%); %Periventricular atrophy=(intracranial space−ventricular space)/intracranial space × 100 (%); %Cortical atrophy=(intracranial space−sulcal space)/intracranial space × 100 (%). (d–f) Representative images of subjects with %Cerebral atrophy z-scores of −2.00, 0.00 and +2.00, respectively.