Table 2.

Atrophy patterns included in the current diagnostic criteria of selected neurodegenerative dementias. Only changes in T1-weighted MRI sequence are included in the MRI signature column. The MRI signatures described are supportive features for the diagnosis unless otherwise stated. PPA primary progressive aphasia. FTD frontotemporal dementia

Disease	Diagnostic criteria	MRI signature
Alzheimer’s disease	McKhann et al. [110]	Disproportionate atrophy in the medial, basal and lateral temporal lobe and medial parietal cortex
Posterior cortical atrophy	Crutch et al. [111]	Predominant occipito-parietal or occipito-temporal atrophya
Logopenic variant PPA	Gorno-Tempini et al. [112]	Predominant left posterior perisylvian or parietal atrophy
Behavioural variant FTD	Rascovsky et al. [113]	Frontal and/or anterior temporal atrophy
Semantic variant PPA	Gorno-Tempini et al. [112]	Predominant anterior temporal lobe atrophy
Non-fluent variant PPA	Gorno-Tempini et al. [112]	Predominant left posterior fronto-insular atrophy
Dementia with Lewy bodies	McKeith et al. [114]	Relative preservation of the medial temporal lobe structuresb
Multiple system atrophy	Gilman et al. [115]	Atrophy of the putamen, middle cerebellar peduncle, pons or cerebellum
Progressive supranuclear palsy	Höglinger et al. [116]	Atrophy predominant in the midbrain relative to pons

^aCore neuroimaging feature of the PCA clinico-radiological syndrome; ^bnon-specific biomarker for DLB, but useful to differentiate from AD