The investigators' rationale was to evaluate whether a 64-slice CT scanner allows accurate measurement of computed tomographic changes in coronary artery flow profiles and whether CT flow measurements are suitable for classifying the significance and hemodynamic relevance of a stenosis and thereby supplement as a functional parameter for morphological stenosis analysis.

A total of 50 patients prospectively underwent computed tomography coronary angiography (CTCA) in a multidetector CT scanner (Brilliance 64, Philips) ± 1 day before or after invasive coronary angiography (ICA). Immediately thereafter, 2 radiologists reviewed the imaging data to detect any vessel segments with morphology poorly evaluable by CTCA. A locally constant cyclical measurement was acquired in these coronary arteries in breath-hold technique during the passage of a 50ml bolus of contrast media. For analysis, time-density curves of the bolus passage were registered in the coronary artery and the aorta (internal reference), the up-slopes were determined and correlated with each other. The results were compared with the ICA findings.

Inclusion Criteria:

• Clinically known or presumed CAD
• Age > 50 years
• Hospitalization for invasive coronary angiography
• Sinus rhythm
• Written informed consent by the patient to participate in the study after comprehensive presentation of the facts

Exclusion Criteria:

• Age <= 50 years
• Contraindications to contrast media administration (medical history of iodine allergy, nephropathy, latent or manifest hyperthyroidism)
• Arrhythmias
• Dyspnea at rest, acute unstable angina pectoris, acute myocardial infarction
• Pregnancy
• Implanted pacemaker
• Unwillingness of patient to consent to the study

people with suspected or known coronary artery disease (CAD)