Which Tc-99m radiopharmaceuticals are commonly employed for imaging the heart?

• A. Tc-99m gothamine
• B. Tc-99m sestamibi and Tc-99m tetrofosmin
• C. Tc-99m oxo-complexes
• D. Tc-99m pertechnetate

Answer: (B)

Tc-99m sestamibi and Tc-99m tetrofosmin are commonly used radiopharmaceuticals for imaging the heart because they are specifically designed to assess myocardial perfusion and function. Both of these compounds are lipophilic cationic agents that accumulate in myocardial cells proportionate to blood flow, enabling visualization of cardiac perfusion.

During myocardial perfusion imaging, when blood flow to the heart muscle is compromised, the uptake of these agents decreases, making them effective for identifying areas of ischemia or infarction. This ability to reflect blood flow dynamics is crucial in diagnosing various heart conditions, including coronary artery disease.

In contrast, other options listed serve different purposes or are not specific to cardiac imaging. For instance, Tc-99m gothamine is not widely recognized for cardiac imaging, and Tc-99m oxo-complexes primarily focus on different organ systems. While Tc-99m pertechnetate is a valuable radiopharmaceutical, it is notably used for imaging the thyroid and detecting gastrointestinal bleeding rather than specifically targeting cardiac functions. Thus, the usage of Tc-99m sestamibi and Tc-99m tetrofosmin in cardiac imaging stands out as the most suitable choice in this context.