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I regret that the answer to question 3 in your Cardiology End Game quiz (BMJ 2011; 342:d3129) is wrong.
An indirect measure of myocardial blood flow is the option called "Cardiac Nuclear Scanning" (more specifically, myocardial perfusion scintigraphy or MPS), and not "Cardiac Stress Testing" (assuming that this is intended to mean Exercise Electrocardiography).
MPS is known by some as a thallium scan (or other named tracers of myocardial perfusion), and it is a widely used noninvasive imaging test that provides three dimensional images of myocardial perfusion, viability and function. It has an essential role in the diagnosis and management of patients with known or suspected coronary disease and is a common component of the emerging subspecialty of cardiac imaging, alongside echocardiography, X-ray computed tomography and magnetic resonance imaging.