Coronary Flow Calculation Method Based on Coronarographic Images: Method Error Estimation

Presented application of the indicator-dilution technique allows calculation of absolute values of the blood flow in the coronary arteries basing on the densitometric analysis of two coronarographic image sequences under some specific conditions imposed on injections of the contrast medium and digital image sequences registration (first sequence is recorded during the slow test administration of the contrast with a reduced amount of the indicator, second injection is recorded during the routine indicator injection). The pilot analysis of 18 patients indicates that there exists a moderate consistency between the results of this method and the clinical assessment. The results of our studies are strictly dependent on the accuracy of the densitomertic measurements and the method of data collection, i.e. manual or semi-automatic. Mentioned above pilot study has been performed on 18 coronarographic examinations. Over 10 thousand images analyses has been needed, so certain automatic aid has been strongly indicated. The measurements of the image intensity has been performed along the same cross-section line of the artery segment. For automatic positioning of the artery cross-section lines in the sequence of the moving (due to heart movement) artery images, a semi-automatic method based on the pattern matching method has been applied. The error caused by automatic data collection has been estimated at less than 10%, total method error did not exceed 23%.