Spatial covariance analysis of FDG-PET and HMPAO-SPECT for the differential diagnosis of dementia with Lewy bodies and Alzheimer's disease

•In the differential diagnosis of dementia with Lewy body and Alzhiemer's disease, spatial covariance analysis of FDG-PET significantly outperforms that of HMPAO-SPECT.•With a relatively small derivation group, spatial covariance analysis of FDG-PET performed similarly to visual interpretation and a univariate quantification method.•Unlike the univariate method, there was little concordance between spatial covariance analysis and visual interpretation of FDG-PET scans, implying that spatial covariance analysis and visual interpretation rely on different sources of variance to separate disease subgroups.