Cardiology

PET imaging can play an important role in the accurate assessment of myocardial perfusion, free from attenuation artifacts. PET is also the gold standard for determining myocardial viability and suitability for coronary intervention.

Using PET to Assess Myocardial Viability

Positron Emission Tomography (PET), utilizing 18-fluorodeoxyglucose (FDG), is a well-recognized method to assess myocardial viability. FDG uptake equates with viability, and as many as 30%-50% of regions felt to be scar by standard nuclear tests are found to be viable with PET. Additionally, categorization of myocardium as viable versus non-viable has important prognostic implications. The identification of viability on the PET scan recommends revascularization, resulting in functional as well as symptomatic improvement in many patients

Using PET for Myocardial Perfusion Imaging

Positron Emission Tomography (PET) myocardial perfusion imaging can be performed with either N-13 ammonia (cyclotron-produced) or rubidium-82 (generator-produced). Advantages of PET versus SPECT include higher spatial resolution, better attenuation correction, quantitation, true stress function analysis, reduced radiation, and higher accuracy. Good candidates for PET include: patients with suboptimal SPECT or SPECT results at odds with the clinical data, obese patients, large breasted women, and diabetics. Presently, PET perfusion studies are best performed with pharmacologic stress (e.g., adenosine, dipyridamole, or dobutamine), and can be completed on modern PET/CT systems in less than 30 minutes.