Nuclear cardiology studies use noninvasive techniques to assess myocardial blood flow, evaluate the pumping function of the heart, and visualize the size and location of a heart attack. Myocardial perfusion imaging is the most widely used technique and is performed many times each day in the comfort of our cardiology office.
Myocardial perfusion images are combined with exercise to assess blood flow to the heart muscle. These studies are often referred to as 'stress tests' because they involve either exercising on a treadmill or simulating exercise by use of a drug such as adenosine.
To obtain images of the heart, a small amount of an imaging agent (such as Cardiolite) is injected into the blood stream during rest and again during exercise or chemical stress. A scanning device (gamma camera) is used to measure the uptake by the heart of the imaging material during stress and at rest. If there is significant blockage of a coronary artery, the images allow a trained cardiologist to detect areas of decreased blood flow.
Myocardial perfusion studies can help identify areas of heart muscle that have an inadequate blood supply as well as the areas of heart muscle that are scarred from a heart attack. These studies quantify the extent of heart muscle with a limited blood flow and can also provide information about the pumping function of the heart. The studies provide necessary information to help identify which patients are at an increased risk for a heart attack and who may be candidates for invasive procedures such as coronary angiography, angioplasty, and heart surgery.
A MUGA scan (Multiple Gated Acquisition scan) is an extremely useful noninvasive tool for assessing the function of the heart. MUGA scans produce moving images of the beating heart. The images help your doctor evaluate information about the health of the cardiac ventricles (your hearts major pumping chambers).
A MUGA scan is performed by attaching a radioactive substance, Technetium 99, to a patient's own red blood cells and then injecting the red blood cells back into the patient's bloodstream. A gamma camera is able to detect the low-level radiation being given off by the Technetium-labeled red cells. Since red blood cells (including those that are radio-labeled) fill the cardiac ventricles, the scan produces images of the chambers of a patient's heart.
MUGA scans give an accurate and reproducible means of measuring and monitoring the ejection fraction of the cardiac ventricles. The ejection fraction is simply the proportion of blood that is expelled from the ventricle with each heart beat and is an excellent measure of overall cardiac function. MUGA scans are widely used to measure heart function prior to a patient starting chemotherapy and to monitor the effects of ongoing chemotherapy on a patient's heart muscle.
Our nuclear medicine services include:
- Chemical & exercise 'stress tests'
- MUGA scans