Figure 2.
Schematic representation of tracers for assessing myocardial perfusion 201Tl and 82Rb are potassium analogs and are transported into the myocyte by cell membrane Na+/K+ pumps. Injected uptake of 99mTc-sestamibi, 99mTc-tetrofosmin, and 18F-flurpiridaz in the myocardium is related to the presence of intact mitochondria. The uptake mechanism of 13N-NH3 is unclear. After being taken into the myocyte, 13N-NH3 underwent metabolic trapping with the conversion of NH3 to glutamine, glutamic acid, and carbamoyl phosphate. 15O-H2O is metabolically inert and freely diffusible tracer