Helping your heart with nuclear imaging

From the IAEA Division of Human Health, Nuclear Medicine and Diagnostic Imaging Section

The IAEA held two workshops and arranged for nuclear cardiology lecturers to visit us. Their support helped train us and find us good gamma cameras. The IAEA also offered us opportunities to collaborate and share experience in several nuclear cardiology activities. Working with the Agency, we received support for multicentric research studies involving developing countries, as well as assistance in disseminating the benefits of nuclear medicine techniques.

Amelia Peix, Deputy Director of Research at the Institute of Cardiology in Cuba

What are cardiovascular diseases?

Myocardial perfusion imaging (MPI) reveals how well the heart muscle is supplied (or perfused) with blood.
(Photo: F.Mut, Uruguay)

Cardiovascular diseases (CVDs) are a group of disorders that can affect a person's heart and blood vessels. The scope of CVDs is vast; they can affect people from all walks of life. While heart attacks, strokes, and high blood pressure are conditions often associated with the fast-food diets prevalent in developed countries, or countries with aged populations, the truth is that over 80% of CVD deaths occur in low and middle income countries. It is in these countries that assistance is most needed. The World Health Organization (WHO) estimates that roughly 30% of all deaths in 2008 were caused by CVDs.

That number is increasing, and by 2030 the WHO estimates that more than 23 million people will be dying annually as a result of CVDs. or comparison, that is equivalent to roughly the entire population of a medium-sized country.

The IAEA is helping in the fight against CVDs by assisting its Member States in using nuclear science and technology to track and monitor CVDs. Nuclear imaging techniques allow doctors to look inside a patient's body and see how organs are functioning.

Seeing things in more detail and visualising the blood vessels and heart muscles allow a better understanding of the disease, how it functions, and to check its overall condition in order to make a diagnosis. Nuclear medicine and diagnostic imaging provide vital tools and accurate imaging techniques that can show us the precise organ function and anatomical detail (examples include; cardiac magnetic resonance imaging (MRI), computed tomography (CT) guided angiography, and nuclear perfusion scintigraphy). These modern imaging devices allow early detection of disease and enable physicians a better diagnosis thereby helping individuals who are suffering from, or are at high risk of developing, CVDs.

One of the imaging technologies widely used is myocardial perfusion imaging (MPI). MPI works by injecting a radiotracer (a compound that can be followed and traced as it moves within the body) which localizes in the heart muscle of the patient in proportion to the blood supply. The radiotracer emits small amounts of radiation that is picked up by a sensitive camera and processed into images. These images reveal how well the heart muscle is supplied (or perfused) with blood. A patient normally exercises on a treadmill or stationary bike during the examination to increase blood flow to the heart and to let the doctor know how the heart performs under physical stress. Techniques such as this have transformed the practice of cardiology and helped in reducing the burden of CVDs worldwide.

MPI is relatively inexpensive, low-risk and tells us a lot about the heart and its functioning.

An example of such transformation is found in Cuba where the IAEA helped with the rebuilding of the clinic's nuclear cardiology departments by providing new equipment and training the staff. Three gamma cameras were installed at the Institute of Nephrology, Centre of Clinical Research and the Institute of Cardiology. This improved the access to state-of-the-art technology and the management of patients with CVDs.

In the ongoing effort to provide up-to-date information to optimize patient management, the IAEA organized a study to assess current worldwide nuclear cardiology practices and radiation exposure. Results were taken from 65 countries who were part of the IAEA Nuclear Cardiology Protocols Cross-Sectional Study (INCAPS) in order to characterize patient radiation doses from MPI and to establish best practices worldwide for the appropriate and safe use of nuclear cardiology. This was done by evaluating the relationship between laboratory use of best practices and patient radiation dose. Through this INCAPS study, multiple opportunities were identified to reduce patient exposure to radiation from heart scans.