Positron Emission Tomography (PET) is a noninvasive medical imaging modality that produces functional rather than anatomical images, thereby providing greater insight to the patient’s condition. Functional imaging means that the body’s metabolism is being shown, as opposed to its structure.
In a cardiac PET scan, the patient is administered with a drug that creates an effect in the body that is similar to exercise and a radiopharmaceutical, typically Rubidium-82, for imaging. Images of the myocardial blood flow are taken both before and after the induced stress and the images are compared to examine blood flow through the heart to determine if narrowing of the coronary arteries is restricting maximum blood flow.
WHY CARDIAC PET
Since 1995, cardiac PET has been approved as a first line test in symptomatic patients. PET is a superior proven technology, which enables early detection, allowing physicians to deliver a diagnosis with less artifactual defects and false-positive results. A dedicated PET only system also has a significantly lower cost when compared to the purchase; install and on-going maintenance of a PET/CT system, making it difficult to financially justify its use within a cardiology practice. Elevated concerns over ongoing Molybdenum shortages, patient radiation exposure, and SPECT reimbursement cuts further validate cardiac PET’s position as the premier technology for the future of nuclear cardiology.
WHO CAN BENEFIT FROM A PET SCAN
• Patients with diffuse, balanced, or multi-vessel CAD
• Patients with physical characteristics that may result in a
suboptimal SPECT scan
• Patients whose prior SPECT scan did not correlate with
other findings or with clinical impression
• Patients unable to exercise
• Patients whose situation requires results be obtained as
quickly as possible; e.g., evaluation of chest pain and add-ons
Cardiac PET has become the leading imaging alternative to reduce radiation exposure, utilizing 82Rb, cardiac PET has shown to have a lower patient exposure level in comparison to a Cardiac SPECT Thallium scan, a Cardiac SPECT 99Tc Sestamibi scan and Computed Tomography Angiography (CTA). Additionally, doses absorbed during 68Ge rod transmission scans were negligible, when compared to CT-based transmission scanning. Therefore, the radiation doses represent a limitation to the generalized use of CT-based transmission measurements with current PET/CT scanning systems. PET scanner combined with 82Rb imaging, can be offered as a highly accurate test with a lower radiation burden to the patient compared to competing technologies.
ADVANTAGES OF PET
• Better Economics
• Improved Efficiency
• Lower Radiation Exposure
• Fewer Attenuation Artifacts
• Improved Resolution