Amyloid-beta imaging with PET in Alzheimer's disease: is it feasible with current radiotracers and technologies?

摘要

Although it afflicts an estimated 26.6 million people worldwide-a figure that is expected to quadruple by 2050-Alzheimer's disease (AD) has yet to be fully understood etiologically, diagnostically, or therapeutically [1]. For decades, the most widely accepted definite diagnosis of AD has been the histological observation of senile plaques composed of amyloid-beta (A beta) and neurofi-brillary tangles comprising tau [2-4]. Theories abound as to the mechanisms behind these deposits of A beta and tau, one of the most prominent of which is the "amyloid hypothesis." This hypothesis proposes that the cleavage of amyloid precursor protein by beta-secretase and gamma-secretase causes A beta 42 to accumulate as senile plaques, which results in synaptic and neuronal injury [5]