Radionuclide ventriculography, a type of cardiac ventriculography, is a form of nuclear imaging, where a gamma camera is used to create an image following injection of radioactive material, usually Technetium-99m (99mTc) labeled red blood cells. In radionuclide ventriculography, the radionuclide has the property of circulating through the cardiac chambers, availing for studies of the pumping function of the heart.[1] In contrast, in myocardial perfusion imaging, the radionuclide is taken up by the myocardial cells, making its presence correlating with myocardial perfusion or viability of the cells.[1]
Radionuclide ventriculography is done to evaluate coronary artery disease (CAD), valvular heart disease, congenital heart diseases, cardiomyopathy, and other cardiac disorders.[1] It exposes patients to less radiation than do comparable chest x-ray studies. However, the radioactive material is retained in the patient for several days after the test, during which sophisticated radiation alarms may be triggered, such as in airports.[1] Radionuclide ventriculography has largely been replaced by echocardiography, which is less expensive, and does not require radiation exposure. Radionuclide ventriculography gives a much more precise measurement of left ventricular ejection fraction (LVEF) than a transthoracic echocardiogram (TTE). Transthoracic echocardiogram is highly operator dependant, therefore radionuclide ventriculography is a more reproducible measurement of LVEF. Its primary use today is in monitoring cardiac function in patients receiving certain chemotherapeutic agents (anthracyclines: doxorubicin or daunorubicin) which are cardiotoxic. The chemotherapy dose is often determined by the patient's cardiac function. In this setting, a much more accurate measurement of ejection fraction, than a transthoracic echocardiogram can provide, is necessary.[1]
