Undergoing Radionuclide Tests

Radionuclide tests involve exposing the individual to a small amount of a chemical called radionuclide, otherwise known as an isotope. This chemical emits a small amount of radioactivity that can be seen on a variety of tests.There are different types of radionuclide chemicals, each one aimed at a different part of the anatomy as they favour different tissues and will concentrate on these areas.

Types of Radionuclide Tests

Radionuclide tests are indicated in the presence of coronary heart disease and can be termed in different ways. These titles can include a radioisotope scan, a myocardial perfusion scan, a positron emission tomography (PET) scan and a single photon computed tomography (SPECT). Essentially they are all radionuclide tests and aim to measure the effectiveness of the heart by examining the blood flow to the heart, the strength and mechanism of the pump action and looking for the presence of heart disease.These types of scans are not as commonly used as an ECG, but can provide a more detailed look at the function and health of the heart.

What is Involved in the Scan

These scans are often attended at specialist units that specifically treat heart patients. Due to the nature and expense of the equipment, not all hospitals have the facility, so travel may be required.

The specialist will often introduce the chemical into the blood supply whilst exercise is taking place or just afterwards. This allows the heart muscle to be working harder, and as the gamma rays are more easily seen in harder working cells, it enables a clearer picture of the heart whilst under strain. The chemical is usually injected into the vein, though it can be inhaled or swallowed depending on the nature of the test.

Whilst the chemical is reaching its target area, the individual will normally be required to be still whilst a large device called a gamma camera is placed onto the chest area. This device picks up gamma rays given out by the chemical as it passes through the heart, allowing the doctor to gain a detailed image of the heart muscle as the messages are sent to and interpreted into visual images on a computer screen.

Risks and Side-Effects

Although this type of testing uses radioactivity, the doses and exposure are performed in a highly controlled area by trained professionals so they are considered to be low risk.Most radioactive waste in the body is excreted in the urine, and no long-term effects are to be expected.It is, however, essential to tell the doctor if you are pregnant as gamma rays can affect a developing foetus.

The only possible side-effects are due to a possible allergic reaction to the chemical, though this is very rare, or because of nervousness and anticipation worries by the patient whilst undergoing the test or awaiting the results.

Radionuclide testing is an important development in modern medicine and allows doctors to make more accurate diagnoses, and therefore the most appropriate treatment options can be selected. They generally carry little risk and have proved to be invaluable in the treatment of heart disease.