Objective: To discuss the clinical value of hybrid SPECT/CT for the detection and estimation of the severity of ischemia caused by coronary lesions, precise localization of coronary artery plaques.Methods: Between July 2009 and May 2010, we performed myocardial perfusion imaging (MPI) on 1075 consecutive patients who suspected CAD or having CAD by physicians.276 patients with at least 1 fixed or reversible perfusion defect on MPI, only 30 patients who accepted Precedence SPECT-MPI/CTCA, and coronary angiography within 90d.All patients underwent a 2-d non-gated adenosine stress/rest protocol.Patients were imaged 1h after administration of the radiopharmaceutical.Two or more experience nuclear medicine physicians and radiologist reviewed the imaging of MPI and CTA, as well as fusion of stress MPI with CTA images blinded to the results of CAG.Two or more interventional cardiologists reviewed the CAG imaging who were unaware of the clinical history and the results from MPI and CTA, the angiographic criterion used to define the presence of significant CAD was visually determined diameter stenosis of ≥50%.Statistical analysis was performed using SPSS software version 13.5 for windows.The results of MPI, CTA and CAG were compared by calculating the sensitivity, specificity,negative predictive value (NPV), and positive predictive value (PPV) of MPI, CTA for the detection of CAD.Results: Thirty consecutive patients (22 men, 8 women: mean age 58.86± 9.44) with at least one perfusiou defect on MPI.Of them 28 reversible, 2 fixed perfusion defects.51 coronary arteries were significant stenosis on CTCA, coronary artery diameter stenosis were ≥50%.50 coronary arteries showed stenoses ≥50% on CAG.The sensitivity、 specificity、 PPV and NPV of fusion imaging in diagnosis CAD were 89.29% (25/28), 88.71% (55/62), 78.12% (25/32),94.83%(55/58), respectively.27 fusion imaging of SPECT/CTCA and CAG combined MPI were both abnormal,56 were normal,6 fusion imaging abnormal but CAG combined MPI normal;1 fusion imaging normal but CAG combined MPI abnormal.The sensitivity、 specificity、 PPV and NPV of fusion imaging in diagnosis CAD were 81.82% (27/33), 98.25% (56/57), 96.43% (27/28), 90.32%(56/62), respectively.SPECT/CTCA fusion imaging compared MPI and CTCA using alone were significant on improving specificity and PPV in diagnosis CAD.Conclusion: Combination of SPECT-MPI and CTCA may provide more exact diagnostic information about the functional relevance of coronary artery lesion interpretation by allowing precise allocation of perfusion defects to its culprit coronary artery.It has important clinical value for diagnosis and treatment strategy of CAD.