In dual-radionuclide myocardial perfusion imaging, which tracer is typically used during stress?

In dual-radionuclide myocardial perfusion imaging, the tracer commonly utilized during stress is 99mTc-Sestamibi. This radiopharmaceutical is particularly effective for assessing myocardial blood flow and viability. Its use during stress testing allows for the simultaneous evaluation of myocardial perfusion under conditions that simulate physical workload or pharmacologic stress.

99mTc-Sestamibi is advantageous due to its favorable characteristics, including optimal photon energy for imaging, quick clearance from non-myocardial tissues, and a good myocardial uptake, which helps in visualizing both ischemic and viable myocardial areas. These properties make it a reliable choice for distinguishing between viable tissue and areas of reduced perfusion, which is critical in diagnosing coronary artery disease.

In contrast, Tl201 Thallous Chloride, while sometimes used, is typically reserved for certain scenarios and is less common in modern protocols due to its longer half-life and higher radiation dose. 99mTc-pertechnetate is mainly utilized for thyroid imaging and does not provide the information necessary for myocardial perfusion assessment. F-18 fluorodeoxyglucose is primarily used in metabolic imaging and does not offer the same direct assessment of perfusion as 99mTc-Sestamibi does. Thus,