Compared to the other non-invasive imaging approach, the values of amyloid PET imaging are more sensitive and accurate than previously established measures by FDG PET or volumetric MRI for diagnostic classification of subjects, suggesting that amyloid PET ligands may be more useful in differentiating among Alzheimer's disease, mild cognitive impairment, and normal aging as well as other neurodegenerative diseases. Therefore, this novel kind of molecular markers may provide advantages to measure amyloid plaques in vivo, have the potential to revolutionize early diagnosis of Alzheimer's disease, and hopefully will facilitate the AD diagnosis with improved accuracy.