Principle of myocardial perfusion (blood
supply) scintigraphy (MPS); Radioactive materials such as thallium 201
(Tl-201) and technetium 99m (Tc-99m) are based on whether or not the heart
muscle can hold it. Thallium is mostly used for testing. The
radiation dose taken with the test is not more than a normal chest X-ray.
Thallium is not harmful to human health, including allergic reactions.
In which cases is Thallium Scintigraphy done?
• In the diagnosis of cardiovascular diseases,
• In the determination of vitality of the heart muscle after
• In the determination of the benefit and necessity of
the application before and after coronary balloon angioplasty,
• In the determination of the relationship between chest pains and
• As a disease screening test in patients with risk factors for
cardiovascular disease ,
• To determine the importance of vascular disease in people with
• To determine the efficacy of treatment after coronary
bypass surgery or drug therapy,
• To determine whether patients have had an infarction, and to
determine the extent and severity of the infarction.
• Do not eat or drink anything containing caffeine (tea, coffee,
cola, chocolate… etc.)
12 hours before the test . • Do not eat anything until
at least 4 hours before the test. However, if you have diabetes and are
taking medication for it, you can continue to eat normally.
• Do not smoke until 3 hours before the test (of course, do not smoke at all!)
• You can drink water whenever you want
• Wear comfortable shoes and clothes as you will be walking on the treadmill.
TI-201 MPS is applied in three ways in the diagnosis of
1. Resting: T1-201 resting images are used to investigate the
presence of viable regions of the heart muscle in patients with myocardial
infarction or chronic coronary patients.
2. With effort: It is the most commonly used perfusion
scintigraphy method in the diagnosis of coronary artery diseases (CAD). A
plastic needle is placed in the patient’s arm for intravenous access. Afterwards,
an exercise test is applied (mostly on the walking belt), after sufficient
effort is made, thallium is injected through the needle in the arm and the
radioactive substance is given to the body through a vein. The substance
goes up to the heart and reaches the heart muscle by passing through the
vessels feeding the heart. In the meantime, these substances are kept less
in the blood muscle section with vascular occlusion, and more in the
non-occluded portion. The patient is then placed under a device called a
gamma camera. A device called a gamma camera rotates around the heart at
regular intervals and transmits the radioactive signals from the heart to a
computer. The computer converts the signals it receives into color images
and analyzes the blood supply of all parts of the heart. The images
obtained before and after the exercise are analyzed, and the areas of impaired
nutrition in the heart are determined.
Radionuclide ventriculography, also known as Multiple Gated
(MUGA), is a routine method used to measure left ventricular ejection fraction,
but it cannot show myocardial perfusion. The form of myocardial perfusion
scintigraphy synchronized with electrocardiography is called “Gated Single
Photon Emission Computerized Tomography” (Gated SPECT). With Gated
SPECT, myocardial perfusion, ventricular volumes, left ventricular contraction
force, wall movements, wall thickening and myocardial vitality can be detected
in one go.
3. Pharmacological (with medication) stress test: Thallium
Scintigraphy can also be performed on patients who cannot exercise, using drugs
that can replace exercise testing.
The sensitivity of exercise thallium scintigraphy in detecting
coronary vascular diseases in scientific studies is around 92%. It can be
used before coronary angiography. The rate of significant coronary heart
disease in patients with normal exercise thallium scintigraphy is
scientifically very low.