Background: There is increasing interest in cardiovascular imaging modalities in
the detection of subclinical and clinically-manifested coronary artery disease (CAD) to improve
cardiovascular outcome in these patients.
Methods: SPECT/CT and PET/CT can be applied for the assessment of myocardial perfusion
and myocardial blood flow (MBF) quantification in CAD detection and characterization,
while CT is predominantly used to identify coronary plaque burden and epicardial
narrowing. In addition, PET/CT plays an increasing role in the detection of the “vulnerable”
plaque in the epicardial artery.
Results: Imaging of myocardial perfusion with SPECT, SPECT/CT and PET/CT is a mainstay
in clinical practice for the identification of flow-limiting epicardial lesions and risk
stratification of patients with suspected or known CAD. In this direction, the concurrent
ability of PET/CT to determine regional myocardial blood flow (MBF) in ml/g/min at rest and during pharmacologically-
induced hyperemic flows allows the calculation of the myocardial flow reserve (MFR) that may unravel
reductions in coronary vasodilator capacity, as functional precursor of the CAD process, monitor its response to
preventive medical intervention, yield important prognostic information in subclinical – and clinically-manifested
CAD, and contributes to identify the flow-limiting effect of single lesions in multivessel CAD. Adding noncontrast
computed-tomography (CT) measurements of coronary artery calcifications has further improved the
reclassification of cardiovascular risk in asymptomatic individuals with intermediate probability of the presence
of CAD. With contrast CT, the non-invasive visualization of coronary vessels, CAD-related plaque burden and
stenosis has become feasible. Yet, a definite identification of the "vulnerable plaque" is still a matter of ongoing
research. PET/CT in conjunction with various positron-emitting radiotracer yields promise in the detection of the
"vulnerable plaque,” that, however, needs further clinical evaluation in CAD patients.
Conclusion: Multimodality imaging in cardiovascular disease is likely to further advances and refine the identification
and characterization of cardiovascular pathology in the near future.