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.