Summary Guidelines for Interpretation of Amyloid PET Scans Using Different Tracers
| Tracer category | Tracer name | Dose and acquisition protocol (clinical) | Visualization | Interpretation criteria for positive scan |
|---|---|---|---|---|
| Food and Drug Administration– approved | 18F-florbetaben | ∼300 MBq; 15- to 20-min acquisition beginning at 45–130 min (research use, 20-min acquisition beginning at 90–110 min) | Gray scale; window images to optimize GM/WM contrast in cerebellum | Increased GM uptake extending to cortical margin involving most slices in at least 1 of 4 target cortical regions: frontal, parietal, precuneus/posterior cingulate, lateral temporal; regional cortical tracer uptake/brain amyloid plaque load scores (20) |
| 18F-florbetapir | ∼370 MBq; 10- to 20-min acquisition beginning at 30–50 min (package insert guidelines) for clinical use or 50–70 min (optimized kinetics for quantification) for research use | Inverse gray scale; window images to optimize GM/WM contrast in cerebellum | Loss of GM/WM contrast due to increased cortical binding in, first, 2 or more brain areas (each larger than single gyrus) with reduced or absent GM/WM contrast or, second, 1 or more areas with intense signal where GM > WM | |
| 18F-flutemetamol | ∼185 MBq; 10- to 20-min acquisition at 60–120 min (research use, 20-min acquisition at 90–110 min) | Color scale (NIH); normalize so that pons is at 90% of activity | Increased GM uptake (>50%–60% peak intensity) or loss of GM matter contrast in at least 1 of 4 cortical regions and 1 subcortical region: frontal, inferolateral parietal, precuneus/posterior cingulate, lateral temporal, striatum | |
| Research | 11C-PiB | ∼555 MBq; dynamic 60- to 90-min acquisition (distribution volume ratio) or 20-min acquisition at 50–70 min (SUV ratio) | Color scale (NIH); window images to optimize GM/WM contrast in cerebellum | No formal guidelines for reading (research use only) |
| 18F-flutafuranol | ∼185 MBq; 20- to 30-min acquisition beginning at 40–50 min | Color scale (NIH); window images to optimize GM/WM contrast in cerebellum | No formal guidelines for reading (research use only) |
GM = gray matter; NIH = National Institutes of Health; WM = white matter.