Which of the following PET myocardial perfusion tracers is described as a model tracer for flow quantitation?

The correct choice highlights Water O-15 as a model tracer for flow quantitation in PET myocardial perfusion imaging due to its unique characteristics. Water O-15 is a freely diffusible tracer that can rapidly equilibrate within myocardial tissue. This allows for accurate measurement of regional blood flow because its distribution reflects the perfusion status of the myocardium almost instantaneously.

Since Water O-15 continuously distributes throughout the myocardial tissue as blood flows into the area, the uptake can be quantified with high precision. This is particularly valuable in clinical and research settings where understanding myocardial blood flow is crucial for diagnosing and assessing various cardiac conditions, including ischemia and infarction.

Other tracers such as Rubidium Rb-82, Acetate C-11, and Ammonia N-13 have their own benefits and applications in myocardial imaging. For instance, Rubidium Rb-82 is widely used for its ease of use and favorable properties for routine clinical practice, but it does not provide the same level of temporal and spatial resolution for flow quantification as Water O-15. Acetate C-11 is often used for assessing myocardial fatty acid metabolism rather than direct blood flow quantitation, and Ammonia N-13, while also valuable for perf