Fig 1. Magnified coronal high-resolution T1-weighted images of the hippocampal region.

A and B, Coronal T1-weighted image of a 68-year-old nondemented control showing discrete enlargement of the choroidal fissures (cf), suggesting medial temporal lobe atrophy (MTA) grade 1, and hippocampal cavities bilaterally (vertical arrows). Note that both hippocampal sulci are not enlarged (horizontal arrows).

C and D, Coronal T1-weighted image of a 54-year-old patient with Alzheimer disease showing enlargement of the hippocampal sulcus, measured between the fimbria and the subiculum (vertical measurement overlays), and enlargement of the choroidal fissures (cf) (MTA grade 1).

E and F, Coronal T1-weighted image of a 76-year-old patient with Alzheimer disease showing enlargement of the hippocampal sulcus (vertical measurement overlays), moderate-to-severe MTA (grade 3) and hippocampal cavities bilaterally (vertical arrows).

G and H, Coronal T1-weighted image of a 93-year-old patient with Alzheimer disease showing severe MTA (grade 4) and a small hippocampal cavity on the right side (vertical arrow). Note that the fimbria appears laterally displaced; this displacement contributes to an increase of the fimbriosubicular distance (oblique measurement overlays).