Cardiac positron emission tomography and the role of adenosine pharmacologic stress

Although single-photon emission computed tomography (SPECT) provides excellent diagnostic and prognostic value in the evaluation of coronary artery disease, its progress has slowed relative to emerging modalities, such as cardiac positron emission tomography (PET). PET imaging provides certain advantages versus SPECT, including higher spatial resolution, improved attenuation correction, and the capability to perform quantitative measurements at the peak of stress. Cardiac PET scanning is a well-validated, reimbursable means to noninvasively assess myocardial perfusion, left ventricular function, and viability by dynamically imaging positron-labeled radiopharmaceuticals in vivo. For the stress portion of rubidium-82 (Rb-82) PET protocols, pharmacologic agents are commonly used because of the short half-life of Rb-82. In light of recent advances in cardiac PET equipment, the expansion of PET/computed tomography scanners, and the resulting potential for streamlined protocols, adenosine may become widely used in electrocardiographic-gated rest–stress acquisition protocols with Rb-82 cardiac PET. With the resolution of technical issues, cardiac PET has an opportunity to become the standard for evaluation of myocardial perfusion in the coming years.