Is there an effect of flat-panel-based imaging systems on quantitative coronary and vascular angiography?

To study the possible effects on quantitative coronary or vascular analyses (QCA and QVA) on images of a flat-panel-based (FP-based) system.

Since a few years, more and more cardiovascular X-ray imaging systems are equipped with flat-panel detectors, replacing the conventional image intensifiers in combination with CCD cameras for the creation of the angiographic images.

To assess any differences in QCA and QVA results from these two types of digital X-ray imaging systems, we performed a quantitative comparison study on images of the Medis coronary and vascular phantom, respectively. All phantom images were acquired on both a FP-based and an image intensifier-based (II-based) imaging system with different system settings (3 different kV-levels and 4 field of view sizes).

The QCA and QVA results showed that all the systematic and random errors for the subsets of the FP-based and II-based systems were very small and satisfy the QCA and QVA reference guidelines, though some of the subsets of the FP-based and II-based coronary and vascular phantom images demonstrate a statistically significant difference. However, given the small magnitude of these under- and overestimations under phantom conditions, these differences are considered clinically irrelevant.

The image characteristics of the FP-based images do not have any significant influence on the results of QCA and QVA analyses. As a consequence, a further optimization of the contour detection algorithm is not necessary for FP-based images, and data from both II-based and FP-based X-ray imaging systems can be used collectively in (multicenter) clinical trials.