SPECT/CT has been generally accepted as a powerful tool for risk stratification in patients with suspected or known coronary artery disease. Combining the results of CAC scoring with MPI findings results in optimal prognostic value, imparting benefits for patient screening and for the diagnosis and treatment of patients suspected of having CAD. And it may offer incremental diagnostic information over myocardial SPECT alone for identifying patients with significant CAD and negative MPI results, or may force the diagnosis confidence of radiologist in these cases.