Unveiling the benefits of a Cardiac PET scan: Things you must know

PET (positron emission tomography) scan is an imaging diagnostic modality that is performed with a special dye, called contrast media. This dye, which has radioactive tracers, makes it easier to study the movement of blood...

Introduction

The doctor or the cardiologist can know a great deal about the heart muscle from a cardiac PET scan.

This test is beneficial in providing an accurate measurement of the flow of blood between the cardiac arteries and the heart. A PET scan can help in detecting coronary artery disease and any damage to the tissue due to a heart attack by picking up injured or dead heart tissue in its images.

The PET cardiac scan also helps the doctor to decide whether a patient can go through angioplasty or may do better with another surgical intervention for the blocked or clogged arteries.

What is a cardiac PET scan?

A cardiac PET scan is a stress test that examines the blood flow to the heart of a patient. The test uses a small amount of radioactive material, which is known as a radioactive tracer. The radioactive tracer is then injected into the vein of the patient. The radioactive tracer most commonly used is Rubidium-82. Unlike a dye or a contrast, it decays in a few minutes and also does not pose a threat to the kidneys. The tracer will settle in the heart muscle in an equal amount to the blood flow.

After this, it highlights different parts of the heart with an intense color. In the case of fully patent coronary arteries, the color will be very intense and gradually it will wean off and become less intense, cooler color when the patient has blockages. It is because the blockages will impede the proper flow of blood in the coronary arteries.

The process is conducted with the help of a cardiac PET scanner that detects the radiation released by the tracer and creates accurate and perfect images of the heart muscle.

The entire imaging diagnosis is done at rest and under stress. It is done with a combination with a medicine that helps in opening the blood vessel's circulation (vasodilator). The purpose of the medication is to stimulate the effects of exercise.

The medication also enables the doctor to ascertain if the patient’s heart is getting supplied with enough blood while being active to the maximum compared to while at rest. The basic use of the PET cardiac scan is to find out the extent of damage to the heart after a heart attack and also evaluate how well the cardiac treatment is working.

Cardiac PET scan vs conventional imaging tests

The cardiac PET scan is beneficial and advantageous in many ways compared to other imaging tests. The first advantage is accuracy. The traditional SPECT nuclear stress test is not very effective and provides images that are blurry and difficult to interpret. On the other hand, a PET scan is synonymous with high spatial, contrast, or temporal resolution of the images. PET images are easy to interpret and do not carry the trouble of false-positive or falsely negative findings. It is marked by dispensing higher quality images and diagnostic accuracy. It does not entail any unnecessary invasive angiography processes in patients.

The second advantage of a cardiac PET scan is the safety element. There is some level of exposure in other diagnostic procedures like X-rays, nuclear, CT, or invasive angiogram of the heart. Radiation exposure to patients in PET scans is much lower, including radiation exposure to technologists, and physicians against CT angiograms or SPECT radiotracers. PET is a first choice as a preferred stress imaging technique according to current guidelines to study coronary artery disease in the young population.

The best part is PET scan is patient-focused, providing timely and efficient care. The patient can have the results of a cardiac PET scan in less than 45 minutes whereas it takes three to four hours for other techniques like a SPECT stress test. It is a huge relief for patients undergoing this PET stress test.

A cardiac PET is also advantageous because it can be equally used in men, women, and people of all sizes providing the same accuracy contrary to SPECT test.

Another benefit and superior quality of cardiac PET scan is that it is capable of measuring absolute blood flow to the heart muscle (coronary flow reserve). It gives a picture and idea about the test being normal or abnormal.

Who benefits most from a cardiac PET scan?

A cardiac PET scan is beneficial for patients who had vague results from other imaging techniques, because unlike them, PET provides high-quality images, and great accuracy, with a capability to gauge coronary blood flow in the different coronary arteries regions. A PET scan is also helpful for those patients who are obese, patients having complex coronary artery diseases, have large breasts, and those for whom an erroneous diagnosis can have the worst clinical consequences.

It is also beneficial in patients when it is paramount to get complete flowing information to rule out balanced and diffuse coronary artery disease or microvascular disease, which may otherwise go unnoticed with alternative imaging technologies.

Furthermore, for patients who are unable to exercise on a treadmill, the cardiac PET scan is a boon. Patients who are scheduled for revascularization procedures especially benefit from the PET imaging scan because it can be precise in indicating the area that is likely to benefit most from coronary stent/angioplasty or bypass surgery.

So, a cardiac PET scan is usually ordered to find cardiovascular disease in patients who have symptoms or those who are genetically disposed such as family history or high cholesterol. A PET scan also closely watches heart health via a treatment course after coronary artery disease has been identified in a patient. It also helps to monitor a patient’s heart condition following an attack while treatment options are being mulled.

Conclusion

So, we have seen all the benefits of a cardiac PET scan and the patients who would benefit most from it. We have also discussed the advantages of a PET scan over other traditional techniques in many ways. However, it comes a little costly and many patients may think twice before availing of it. It has been in existence for more than 40 years, yet it is scarcely used, mainly for the cost element.

Lack of education is also another reason for its limited availability. Only a small number of cardiologists practice and have the opportunity to gain exposure and training in this advanced technology. Hence, there is limited understanding and awareness of the advantages of cardiac PET scans and their results. But the good thing is that it is gaining popularity and eventually the majority will embrace it for the sake of patients.

FAQs

Does cardiac PET scan show blockages?

The cardiac PET test is often utilized to diagnose heart conditions such as coronary artery disease (CAD). The findings of a cardiac PET scan help doctors to see any significant blockage of the coronary artery, and the degree of heart damage after a heart attack.

What are the positive effects of PET scans?

A PET scan is fantastic at revealing the functional performance of specific body areas rather than merely displaying their visual appearance. PET scans are mainly beneficial for investigating confirmed cases of cancer to ascertain the spread of cancer along with the efficacy of the treatment.

What risk factors should we consider of a cardiac PET scan?

One has to consider the risks and discomfort of a cardiac PET scan as well despite all safety measures taken by the facility or the lab. There could be some untoward incidents and problems during the procedure that need to be considered. It could include disorders of the heartbeat, cardiac arrest, heart attack, and death during the cardiac stress test.

What is a disadvantage of a PET scan?

PET scans may produce inaccurate outcomes when the chemical equilibrium in the body of the patient is disrupted. It is especially true in patients who suffer from diabetes. Even in cases where the patient has recently eaten food within a few hours before the scan, it may be negatively impacted due to fluctuations in blood sugar or blood insulin levels.

Is PET scan good or bad?

Generally speaking, PET scans are the safest and they rarely lead to problems. In PET scans there is a very low amount of radiation from the radioactive tracer. Moreover, it doesn't stay in the patient’s body for too long. It is only that the patient must drink lots of water after a PET scan to expel the radioactive drug from the body.

What is the cost of a cardiac PET scan?

The cost of a cardiac PET scan may range from Rs 23000 to 27000/-. To get an accurate quote contact a certified diagnostic centre at the earliest and also to get the best results.

Is a PET scan better than an angiogram?

A cardiac PET scan is considered the gold standard to decide whether to go for stents or bypass surgery. It is better than a coronary angiogram in deciding the same. The quantitative myocardial perfusion by a cardiac PET scan is unparalleled.