Figure 2. Representative Images of Carbon 11–Labeled Pittsburgh Compound B Positron Emission Tomography ([¹¹C] PiB-PET) and Magnetic Resonance Imaging (MRI) .

A, A cognitively normal (CN) older adult in the group with no amyloid-β (Aβ) deposition with a typical negative amyloid scan of [¹¹C] PiB-PET (left), showing only nonspecific uptake in the white matter (WM) tract (arrowhead) and no PiB uptake in cerebral gray matter (GM), as well as no significant bilateral temporal atrophy in brain MRI (right). B, A CN older adult in the group with Aβ deposition with a typical positive amyloid scan of [¹¹C] PiB-PET, showing PiB retention in cerebral GM (left, arrowheads) and bilateral temporal atrophy in MRI (right, yellow circle).