In the field of coronary artery disease (CAD) are several non-invasive imaging techniques for diagnostic and risk stratification purposes such as echocardiography, perfusion imaging (cardiac stress SPECT - single photon emission computed tomography - and stress PET - positron emission tomography), non-invasive cardiac computed tomography angiography (CTA) and combined perfusion-anatomy (PET-CT) studies. There are an estimated 40 million noninvasive cardiac tests performed each year (Mark DB 2003). For echocardiography and SPECT imaging, reimbursement from Medicare encompasses approximately 30% of all payments, totaling over $1 billion in the year 2000 (ACC 2003). There are, however, basic questions about cardiovascular imaging techniques that need to be addressed: how does technology benefit the patient? It is worth the cost? Is treatment plan enhanced? Is outcome better? Data are necessary for addressing these questions and if appropriate for acceptance among practicing physicians, patients and third party insurers.