I would suggest two articles: Small and others, Arch Neurology 2012;69(2):215-222 and Prestia and others in Neurology 2013;80:1048-1056. Both of these articles are about the role of PET in predicting AD in those who are at high risk because of MCI or because of family Hx of AD.
I would go for this. It's new, updated, well written and contains useful picture. It is edited by Prof. Dierckx. You can find via this link and have a free preview.
more you can visit the ADNI site [but I suppose you allready did it]
further, you could follow / ask Giovanni Frisoni [www.centroalzheimer.org], who is Clinical neurologist, Full Professor of Clinical Neuroscience at the University of Geneva, Switzerland, and Head of the Memory Clinic of the Geneva University