The competent cardiologists and radiologists at Aster Hospitals provide most advanced cutting edge technologies for diagnosing and treating coronary artery diseases. Myocardial perfusion imaging studies are one of the advanced tools for knowing and treating perfusion of blood in the heart muscles. The procedure involves scanning the heart by injecting a radiopharmaceutical agent in the vein to check the flow of blood in the heart muscles.
Myocardium is the muscular layer of the heart. In coronary artery diseases, there is a deficient blood supply to the muscles in the heart that results from narrowing or blocking of the arteries. Myocardial perfusion imaging studies help the doctor confirm the diagnosis of coronary artery disease and initiate treatment or intervention for optimal heart health.
Myocardial perfusion imaging helps the doctor assess whether:
- Some areas of the heart have low blood flow during exercise or at rest.
- Your chest discomfort or pain is due to a heart condition. If the test is normal, the doctor can focus on other causes of chest discomfort.
- You need intervention for your heart health, such as coronary artery bypass surgery (CABG), stenting, or any percutaneous cardiac intervention (PCI)
- You need immediate intervention like cardiac catheterization or angiogram.
- Your bypass surgery or stenting has been successful.
- You can handle strenuous physical activity.
- You have had a heart attack in the past.
- You are at risk of a heart attack.
There are two methods of doing myocardial perfusion imaging. Both tests are nuclear imaging tests and non-invasive. Your doctor may advise one of the scans as needed:
- Positron emission tomography, or PET, uses multiple sodium iodide crystals. With better spatial resolution, it allows more accuracy than SPECT. In addition, PET images provide information on quantifying blood flow in the heart muscles. They give accurate results in assessing the risk of cardiovascular mortality.
- Single photon emission computed tomography, or SPECT, uses a single sodium iodide crystal. It assesses the perfusion and viability of the myocardium.
Both myocardial perfusion imaging scans are safe, and the radiation exposure is minimal. The radioactive material passes out through urine within 24 hours of the test. However, the tests are not advisable during pregnancy and in lactating mothers.
Health Conditions Treated
- Chest pain or angina
- Chest discomfort while exercising or walking
- A history of heart attack and the present scenario
- Risk or possibility of coronary artery disease
- Assessment of viability of myocardium
- After bypass surgery, angioplasty, or stenting
FAQs
At Aster Hospitals we provide the highest quality of care and a transformative experience for all your healthcare needs. With our network of multi-speciality hospitals, specialised doctors, and world-class technology, we bring global standards of medical care to our patients.
What precautions should I take before going for myocardial perfusion imaging scans?
Tell your doctor about the medicines you are taking, if you have a pacemaker, or if you are pregnant or breastfeeding.
What shall I be required to do after the test?
After the test, you should get up slowly from the table to avoid dizziness. Drink plenty of water. Your doctor shall discharge you on the same day if your scan is normal.
What if my scans are not normal?
Your doctor shall advise treatment options according to the perfusion defects in your heart muscle.
Are myocardial perfusion scans safe?
Yes. The scans are safe. The radioactive material is flushed out in the urine.
Is there any food item that I should avoid before the test?
Your doctor shall advise you on the gap you should keep between food intake and the test. Usually, doctors advise 4–6 hours of fasting before the test. You may be asked to stop caffeine and smoking 24 hours before the test.
Can I do routine work after the test and discharge from the hospital?
Yes. If your scan is normal, your doctor will allow you to return to your routine the same day.
Will I be required to stay back in the hospital after the scan?
If your scans show severe heart disease, your doctor may recommend same-day cardiac intervention to restore the blood flow in the heart muscles.
Can I continue breastfeeding my baby if advised to get the scans done?
Tell your doctor that you are breastfeeding the child. The scan may not be safe for the baby.
Advanced Technology & Facilities
Personalized attention is given to each person undergoing tests or treatment at Aster Hospitals.
Diagnostics
Your doctor may advise you to undergo a SPECT or PET test to determine whether your heart muscles have adequate blood flow while resting or exercising. Both tests have similar processes. In SPECT, a single sodium iodide crystal is used, while in PET, multiple sodium iodide crystals are used.
Rest SPECT or PET scan
The procedure is as follows:
- The tests are conducted by a doctor and a nuclear medicine technologist.
- You shall be advised to stop eating and drinking water 4–6 hours before the procedure, avoid coffee, and alter the medication schedule if you are taking any. Your doctor may ask you not to smoke 24 hours before the test.
- While taking the scans at rest, you shall be asked to lie on a table. The technician shall tie a cuff around your upper arm to check blood pressure readings and place electrodes on your chest, arm, and legs to record ECG. The doctor shall set up an intravenous line in the vein in your arm through which a radioactive material, a radionuclide called a tracer, is injected into your vein.
- Following this, your table slides inside a big circular machine fitted with cameras.
- The tracer in the vein emits photons, which are picked up by the gamma cameras placed around your chest in the machine. Gamma cameras are linked to a computer that converts the gamma camera’s signals into a series of explicit images of the blood flow through the heart. Computer images are also used to create three-dimensional images of the heart, which are taken in several planes in various cuts.
Stress SPECT or PET scan
The preparation for the stress test is similar to the rest test, except that you are asked to walk on a treadmill or cycle a stationary bike with the leads attached and the recordings are taken. If you cannot exercise, the doctor will give you medicine through your IV line. The medicine produces an effect similar to exercise on your body.
The PET or SPECT scan takes about 1–3 hours for completion. If the results are normal, your doctor may allow you to resume your normal activities.
Your doctor interprets the SPECT and PET scan test results according to the tracer uptake. Areas with good perfusion are brightly lit on the screen, whereas areas with poor perfusion do not take the tracer or take very little.
The interpretation by the doctor may go like this:
- A normal tracer uptake shows the heart muscles are fully perfused with blood. It would help you if you continued with healthy lifestyle habits.
- If the tracer uptake is slight or absent in some areas during exercise but normal at rest, it may depict one or more blockages in the coronary arteries; the tissue is viable and can be revived.
- When a tracer is not visible in an area during exercise or at rest, it may depict a heart attack in the past or a current coronary artery disease with blockage. If the tissue is still alive, your doctor shall take immediate measures to revive it and help the heart muscle regain blood flow.
- Your doctor can visualize the reversible or irreversible perfusion defects.
