What does radionuclide myocardial perfusion imaging compare in patients with suspected angina?

Radionuclide myocardial perfusion imaging is primarily used to evaluate cardiac blood flow and assess the functional status of the coronary arteries in patients who may have angina or other forms of ischemic heart disease. The correct answer is that this imaging technique compares myocardial perfusion at rest and during exertion.

This comparison is fundamental because it helps to identify areas of the heart that may not receive adequate blood flow when the heart is under stress, which is often when symptoms of angina are elicited. By assessing perfusion during both states, physicians can determine if there are reversible defects indicating ischemia, which would not be evident when the patient is at rest.

In the context of diagnosing coronary artery disease, this approach enables clinicians to understand how well the heart can supply blood under conditions of increased demand, highlighting the significance of the coronary arteries' ability to accommodate changes in workload. If perfusion is adequate at rest but not during exertion, it suggests the presence of a significant coronary obstruction, which could lead to angina during physical activity.