Figure 1.

Amyloid deposition in cognitively normal elders, mild cognitive impairment and Alzheimer's disease. (a) Representative ¹¹C-PiB positron emission tomography images from a cognitively normal older individual (CN) without evidence of amyloid pathology (PiB-), from a normal older individual with elevated PiB retention indicating amyloid deposition (PiB+), and from a patient with mild Alzheimer's disease (AD) with extensive amyloid deposition. (b) Scatterplot of PiB distribution volume ratio (DVR) for CN, mild cognitive impairment (MCI) and AD groups, demonstrating a subset of CN and MCI individuals with evidence of amyloid deposition in the range of AD patients.