How Myocardial Perfusion Imaging Helps Detect CAD

A myocardial perfusion scan is a valuable tool for diagnosing and managing heart conditions. It plays a crucial role in detecting coronary artery disease (CAD), assessing heart function, and guiding treatment decisions.

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Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide. It occurs when the coronary arteries that supply oxygen-rich blood to the heart become narrowed or blocked due to plaque build-up. Early and accurate detection of CAD is crucial for effective management and prevention of severe complications such as heart attacks. One of the most reliable diagnostic tools for CAD is Myocardial Perfusion Imaging (MPI), a type of nuclear cardiology test that assesses blood flow to the heart muscle.

What is Myocardial Perfusion Imaging?

Myocardial Perfusion Imaging (MPI) is a non- invasive imaging technique that evaluates the blood supply to the heart muscle both at rest and under stress. It uses a small amount of radioactive tracer, such as technetium-99m or thallium-201, which is injected into the bloodstream. A gamma camera detects the radiation emitted by the tracer, producing images of the heart that help identify areas with inadequate blood flow.

How MPI Detects Coronary Artery Disease

MPI is particularly effective in diagnosing CAD because it can reveal areas of the heart that receive reduced blood supply due to narrowed or blocked coronary arteries. The test is performed in two phases:

• Resting Phase - The patient receives the tracer injection while at rest, and images are taken to assess baseline blood flow to the heart.

• Stress Phase The patient undergoes physical exercise on a treadmill or receives a pharmacologic stress agent (such as adenosine or dobutamine) to simulate the effects of exercise. The tracer is injected again, and additional images are captured. By comparing the rest and stress images, doctors can determine if there are any areas of reduced blood flow, which is indicative of coronary artery disease.

Key Benefits of MPI in CAD Detection