Which of the following radiopharmaceuticals is commonly used for cardiac imaging?

Tc99m-sestamibi is the radiopharmaceutical commonly utilized for cardiac imaging due to its properties that allow for effective visualization of myocardial perfusion. This radiotracer is a lipophilic compound that readily penetrates cardiac tissue, primarily during instances of increased blood flow, making it ideal for assessing coronary artery disease and myocardial viability. It is taken up by healthy myocardial cells, while areas of reduced blood flow will exhibit decreased uptake, thus helping to identify ischemic regions of the heart.

In contrast, Tc99m-DTPA is typically used for renal imaging rather than cardiac applications, as it concentrates in the kidneys. I-131 is primarily used for thyroid imaging and treatment due to its ability to target thyroid tissue, and Ga-67 is utilized in oncologic and inflammatory imaging but is not specific to cardiac assessment. Hence, Tc99m-sestamibi stands out as the most appropriate choice for cardiac imaging in nuclear medicine.