The purpose of this study is to compare the extent of coronary vessel stenosis between coronary spasm-induced angina attacks (named vasospastic angina, VSA) patients and health volunteers by multi-detector computed tomography angiography (MDCTA), and to evaluate the diagnostic efficacy of MDCTA in patients with VSA.

Vasospastic angina (VSA) was characterized by transient ischemic ST-segment change during angina attacks. Coronary spasm provocation test, as a diagnostic golden standard, has been widely used for the management of VSA according to JCS 2013 guidelines.

With regard to the characteristics of spasm segment, had been clearly described by other invasive imaging methods including intravascular ultrasound and optical coherence tomography. However, there is potential risk during these invasive procedures, such as severe myocardial ischemia or fatal arrhythmia.

Presently available imaging test for coronary artery disease including multi-detector computed tomography angiography (MDCTA) with high diagnostic accuracy to evaluate coronary artery stenosis. However, the diagnostic accuracy of MDCTA in patients with VSA is lacking.

Therefore, more efficient and safe noninvasive diagnostic method is required for the detection of angina-like attacks patients.

Inclusion Criteria:

• Onset of angina-like attack at rest, during effort, or during rest and effort.
• Patients will be scheduled to undergo multi-detector computed tomography angiography and coronary angiography with an ergonovine provocation test.

Exclusion Criteria:

• Evidence of acute coronary syndrome, cardiomyopathy and valvular heart disease.
• More than 50% stenosis detected by coronary angiography .
• Renal insufficiency (serum creatine>2.5 mg/dl).