Table 1.

Physical properties of perfusion PET tracers

Radiotracer	Half-life	Availability	Mechanism	Comments
15O-Water	122 s	On-site cyclotron	Metabolically inert, diffuses freely across capillary membrane	Ideal tracer for MBF quantification, near perfect linear relationship between flow and tracer uptake.26,27 100% myocardial extraction fraction. Intermediate image quality due to long positron range.
13N-Ammonia	9.96 min	On-site cyclotron	Diffusion and metabolic trapping	>80% myocardial extraction fraction. High image quality due to short positron range and myocardial retention. Validated against 15O-Water.27,28
Rubidium-82	76 s	Generator	Myocardial uptake via Na/K-ATPase	Short half-life allows rapid protocols. MBF underestimation at high-flow rates due to roll-off phenomenon. 65% myocardial extraction fraction. Moderate image quality due to long positron range.
18F-Flurpiridaz	110 min	Regional cyclotron	Rapid uptake by myocyte mitochondrial complex	Near linear kinetics of tracer uptake and MBF. Good image quality due to short positron range. High myocardial extraction fraction (94%). Current evaluation in Phase III trials. Does not require on-site cyclotron and therefore allows greater access.