Coronary computed tomography angiography (CTA) enables non-invasive detection of coronary atherosclerotic plaques. In turn, myocardial perfusion imaging (MPI) using positron emission tomography (PET) allows non-invasive measurement of myocardial blood flow. Hybrid imaging refers to combining data from two different imaging modalities. Anatomical information from CTA and functional information from MPI are potentially complementary in evaluation of coronary artery disease (CAD). However, the clinical benefit and optimal use of cardiac hybrid imaging are unclear. 

We investigated the selective combined use coronary CTA and PET MPI in evaluation of stable symptomatic patients with suspected CAD. Patients first underwent coronary CTA to detect coronary stenoses, and those patients who presented with a suspected obstructive stenosis on CTA also underwent PET MPI to study the hemodynamic significance of the stenosis. We found that obstructive CAD could be ruled out by coronary CTA alone in about half of the patients, associated with an excellent prognosis. Instead, reduced myocardial PET perfusion was associated with an impaired outcome. 

Renal injury is a potential complication of iodine contrast agents. We found a low incidence of persistent renal dysfunction after coronary CTA in stable patients with suspected CAD. We also studied an integrated risk score derived from CTA findings, and found this score to predict future adverse events in patients with suspected CAD. Finally, we assessed hybrid PET/CTA findings in symptomatic patients with previous coronary artery bypass grafting. The integrative assessment allowed the evaluation of myocardial perfusion defects and their co-localization with the supplying coronary arteries or bypass grafts.