Amyloid PET in clinical practice: Its place in the multidimensional space of Alzheimer's disease

• Amyloid imaging has been validated as a biomarker for cerebral β amyloidosis.
• Biomarkers are essential for progress in therapy for Alzheimer's disease.
• They may have a role in clinical diagnosis under specific conditions.
• An evidence-based medicine approach will have to prove their added value.
• We position amyloid imaging within a multidimensional model of Alzheimer's disease.

Amyloid imaging is currently introduced to the market for clinical use. We will review the evidence demonstrating that the different amyloid PET ligands that are currently available are valid biomarkers for Alzheimer-related β amyloidosis. Based on recent findings from cross-sectional and longitudinal imaging studies using different modalities, we will incorporate amyloid imaging into a multidimensional model of Alzheimer's disease. Aside from the critical role in improving clinical trial design for amyloid-lowering drugs, we will also propose a tentative algorithm for when it may be useful in a memory clinic environment. Gaps in our evidence-based knowledge of the added value of amyloid imaging in a clinical context will be identified and will need to be addressed by dedicated studies of clinical utility.