Insensitivity of visual assessment of hippocampal atrophy in familial Alzheimer's disease.

Medial temporal atrophy is a well-established marker for Alzheimer's disease (AD). However, due to normal variation in the size of medial temporal structures and variability in how radiologists interpret images, the use of clinical reads in establishing the presence of pathological atrophy is imprecise. A limitation of studies of magnetic resonance imaging (MRI) measures in AD is diagnostic uncertainty as it can be unknown if pre- or early-symptomatic subjects go on to develop AD and most subjects do not undergo autopsy verification of the diagnosis.