Types of Nuclear Heart Scanning
Nuclear Heart Scanning is among the standardized and most established of cardiac testing technologies. It used for diagnosis, management and prevention of heart problems, including heart disease, cardiomyopathy and heart attacks. There are two, main types of nuclear heart scanning procedures:
1. Single Positron Emission Computed Tomography
This is also called SPECT or Cardiac SPECT and is among the more preferred of the two heart scanning technologies. It is commonly recommended as a part of nuclear scanning when Coronary Artery Disease (CAD) is suspected. Often, cardiac SPECT is combined with Cardiac Stress Test. This helps to highlight the flow of blood when it is subjected to moderate degree of pressure, i.e. the stress induced by making the patient walking/jog upon a treadmill. This is vital since a Stress Test can specifically indicate the performance of the cardiac muscles when they are made to beat faster and work harder than their usual, resting mode.
SPECT scanning is typically used to decode any muscle in the heart that is showing signs of damage or the presence of dead heart muscle/tissue. Dead or inactive cardiac muscles are often found among patients who have previously suffered a heart attack. Many patients who have suffered a silent heart attack don’t even realize the extent of damage their heart has undergone until a SPECT is ordered by a cardiologist who suspects compromised cardiac performance. In such cases, results of cardiac SPECT scanning form the basis of identifying a potentially fatal heart attack in the future. SPECT can be specially used for evaluating the performance of the heart's ventricles. For instance, SPECT scanning can indicate the amount and the rate at which the left ventricle is pumping blood into the body. Weaker-than-average pumping performance can lead to a heart attack or heart failure. In conventional SPECT studies, tracers like Thallium-201 and Cardiolite® are used.
2. Positron Emission Tomography
PET is quite similar to SPECT in terms of the scanning procedure but it uses slightly different types of tracers. PET scanning is known to provide more detailed images of the heart’s muscles, making it a bit more popular. However, most cardiologists still tend to think of SPECT as the more established diagnostic scanning procedure. PET might be newer and provide some immediate advantages but it also has some technical limitations. Further, PET scanning machines are not as prevalent across healthcare facilities.. Cardiac PET scanning serves the same set of purposes achieved through SPECT, including diagnosis of CAD, identifying damaged heart muscles, decoding dead heart muscles and evaluating the heart's overall pumping performance.
Yes, PET scanning is able to provide slightly clearer pictures than SPECT but this is not as applicable in the cardiac niche, i.e. PET has a certain advantage when scanning thicker layers of tissue such as those found in abdominal or breast tissue. However, PET is known to provide better conclusions than SPECT in terms of helping to identify whether CAD has affected more than one of the heart’s blood vessels. Many times, PET scan is combined with a SPECT scan for ensuring that the best possible diagnostic images are obtained.