Cardiac P.E.T. (Positron Emission Tomography) is one of the newest, most advanced methods for physicians to study the heart. (insert info on HSS offering Cardiac PET) P.E.T. scans are non-invasive and painless. They unveil the function/physiology of organs and tissues, while other imaging techniques (e.g., x-ray, MRI, and CT scans) only show structure. These studies can reveal the health of the vessels supplying blood to the heart, heart muscle and surrounding tissue. With P.E.T. imaging, physicians can evaluate areas of the heart muscle that are not receiving adequate blood flow due to blockages in the arteries, detect coronary heart disease, assess tissue scarring due to a heart attack, and determine if bypass surgery or angioplasty will benefit a damaged part of the heart.
How it works: Rubidium-82, a radioactive tracer that is injected into the patient’s arm. The blood stream carries the tracer to the heart muscle which produces an image of the blood flow in the heart. A special P.E.T. camera detects the emitted positrons and constructs a picture of the heart.
What you should expect: Your test should take about 60 minutes to perform. Your medical history and medications will be reviewed and a consent form will be signed. Before the study begins, you will be asked to lie still on the P.E.T. imaging table. The table will be positioned into the scanner and a quick scan will be obtained to ensure the patient’s heart is positioned properly in the P.E.T. camera’s field of view. An intravenous line (IV) will be placed in your arm or hand to administer the pharmacologic agent and tracer. Electrodes will be placed on your chest to monitor your heart throughout the procedure. You will lie on a bed and the bed will begin to pass slowly through the P.E.T. scanner.
A nuclear tracer will be administered intravenously in your arm or hand. You will receive an injection of a pharmacologic drug that increases blood flow through the normal arteries. However, the blood flow will not be increased in arteries that are blocked or in tissue that is damaged. The differences in blood flow are detected by the P.E.T. scanner, which creates a picture of the blood flow to the heart tissue.
a) Cardiac PET imaging demonstrates excellent diagnostic accuracy, with improved sensitivity and specificity, compared with Cardiac SPECT, which was confirmed by two recent meta analysis studies. 1,2
b) Superior image quality due to higher spatial resolution and higher tracer energy levels. This results in higher interpreter confidence and fewer false positive studies compared with Cardiac SPECT. This is true in all patients, but especially in obese patients or patients with large body habitus. 3,4 Fewer false positive studies will result in fewer patients referred for normal cardiac catheterization.
c) Cardiac PET imaging with rubidium allows studies to be required with low radiation exposure. The overall patient radiation exposure with Cardiac PET imaging is one quarter of Cardiac SPECT perfusion imaging. 4,5,6 The markedly lower radiation exposure with Cardiac PET has significant beneficial public health implications.
d) The testing protocol is much shorter than Cardiac SPECT (45 minutes compared with 3.5 hours), providing greater laboratory efficiency and higher patient satisfaction.