Knowledge about spatial and temporal patterns of beta-amyloid (A beta) accumulation is essential for understanding Alzheimer disease (AD) and for design of antiamyloid drug trials. Here, we tested whether the regional pattern of longitudinal A beta accumulation can be predicted by baseline amyloid PET. Methods: Baseline and 2-y followup F-18-florbetapir PET data from 58 patients with incipient and manifest dementia due to AD were analyzed. With the determination of how fast amyloid deposits in a given region relative to the whole brain gray matter, a pseudotemporal accumulation rate for each region was calculated. The actual accumulation rate of 18F-florbetapir was calculated from follow-up data. Results: Pseudotemporal measurements from baseline PET data explained 87% (P < 0.001) of the variance in longitudinal accumulation rate across 62 regions. The method accurately predicted the top 10 fast and slow accumulating regions. Conclusion: Pseudotemporal analysis of baseline PET images is capable of predicting the regional pattern of longitudinal A beta accumulation in AD at a group level. This approach may be useful in exploring spatial patterns of A beta accumulation in other amyloidassociated disorders such as Lewy body disease and atypical forms of AD. In addition, the method allows identification of brain regions with a high accumulation rate of A beta, which are of particular interest for antiamyloid clinical trials.