Gray matter volume, white matter hyperintensity volume, and global CBF by cognitive group. *p < .05, **p < .01; White matter hyperintensity volume was log-transformed; Model predicted volumes for gray matter and white matter hyperintensities were adjusted for age, sex, APOE ɛ4 status, pulse pressure, and total intracranial volume; global CBF was adjusted for age, sex, APOE ɛ4 status, pulse pressure, and FDG PET. CU: cognitively unimpaired; Obj-SCD: objectively-defined subtle cognitive decline; MCI: mild cognitive impairment.