[Normal and pathological hippocampal imaging in geriatric patients].

The hippocampus is a small internal temporal cerebral structure, which plays a primordial role in the mechanisms of memory. Magnetic resonance imaging (MRI) is the reference imaging modality for the hippocampal analysis. In older adults, dementia represents the majority of hippocampal diseases, but other specific pathologies must be known in the differential diagnosis. Many hippocampal abnormalities are represented by a loss of substance (atrophy). However, most acute or recent hippocampal damage is detected by MRI signal abnormalities. The aim of this article is to offer a pictorial review of the normal and pathological hippocampal aspects of older adults, during degenerative, infectious, vascular, inflammatory, tumoral, toxic and metabolic disorders.