Progress in quantitative coronary arteriography: improved accuracy for small vessel diameters with 2nd generation QCA systems

It has been known that the well-established 1st generation QCA systems overestimate small vessel sizes. In 2nd generation QCA systems new algorithms are introduced which correct for this important source of error in quantitative angiography. Therefore, in this investigation the authors evaluated if the cardiologist can obtain more accurate measurements with 2nd generation QCA systems than with 1st generation systems. For this analysis three 2nd generation QCA systems (CMS, QANSAD and AWOS) were compared with the well-known 1st generation systems CAAS and ARTREK. Using an arterial phantom the overall accuracy, the precision and an additional accuracy value (acc 2) for small vessel diameters of each QCA system were determined The results demonstrate that CAAS and ARTREK overestimate small vessel diameters significantly, whereas with the 2nd generation QCA systems accurate and reliable measurements of small coronary dimensions down to 0.5 mm are attainable. This progress in accuracy is of particular relevance in the analysis of moderate to high grade coronary stenoses.