Viability imaging by cardiac computed tomography

First-pass perfusion and delayed enhancement cardiac imaging have been shown to be feasible by cardiac CT. However, questions remain about its reliability, and ideal scanning parameters have yet to be fully established. In general, scar imaging with cardiac CT typically requires 2 scans, with first-pass perfusion information derived from the same data set used to visualize the coronary arteries. Reduced contrast enhancement on first-pass cardiac CT images represents reduced perfusion. Higher doses of contrast are required to perform viability imaging by cardiac CT. Approximately 10 minutes after contrast administration, viability information is obtained by performing a second (noncontrast) scan. In addition to the concepts of perfusion and viability imaging by cardiac CT, we review parameters such as scan timing, tube settings, contrast delivery, reconstruction, and postprocessing techniques, as well as the associated pitfalls and technical limitations in perfusion and viability imaging by cardiac CT.