Cardiac PET-CT for monitoring medical and interventional therapy in patients with CAD: PET alone versus hybrid PET-CT?

This review focuses on optimal use of PET and PET-CT in monitoring medical and interventional therapy in patients with CAD. PET provides quantitative measurement of absolute myocardial blood flow and thus permits comprehensive physiological assessment of the coronary circulation. Hybrid PET-CT, in particular CCTA, adds anatomical information to maximal MBF measurement and so facilitates distinction of triple vessel focal epicardial disease from coronary microvascular disease or diffuse coronary atherosclerosis without focal stenoses. Hybrid PET-CT also may be of value in determining appropriateness and feasibility of percutaneous interventional therapy for chronic total coronary occlusion. PET alone, however, is the preferred modality to address functional status of the coronary circulation and response over time, if required, to medical or interventional therapy. CT at a minimum provides attenuation correction. More detailed CCTA should be added only when a well-defined need for anatomical information is required to answer the clinical question posed.