1) Establish normal value for coronary calcium scoring in Taiwan. 2) Find out the relationship of coronary calcium deposition and coronary artery stenosis. Propose a clinical management guideline based on coronary calcium score. 3) Evaluate sensitivity/specificity of coronary CT angiography and the influence of coronary calcium score on coronary CT angiography. 4) Evaluate the clinical application of myocardial enhancement measurement.

Computed tomography is evolving as a tool for noninvasive diagnosis of coronary artery disease. Coronary calcium deposition amount is an established independent coronary artery disease risk factor. However, coronary artery stenosis seldom occurred in the same location as calcium deposition. With the advent of 16-detector-row multislice spiral CT, direct visualization of coronary artery is possible. But it remains a great challenge to obtain diagnostic quality image in the beating heart. Small distal vessels may not be adequately visualized. Artifacts from severe calcification or coronary stent may render diagnosis difficult. The clinical implication of coronary calcium score, indication of coronary CT angiography and myocardial enhancement measurement should be further studied. The purposes of this study are: 1) Establish normal value for coronary calcium scoring in Taiwan. 2) Find out the relationship of coronary calcium deposition and coronary artery stenosis. Propose a clinical management guideline based on coronary calcium score. 3) Evaluate sensitivity/specificity of coronary CT angiography and the influence of coronary calcium score on coronary CT angiography. 4) Evaluate the clinical application of myocardial enhancement measurement.

Inclusion Criteria:

• coronary artery disease admitted for coronary angiography

Exclusion Criteria:

• Heart failure, irregular heart rate