Digital Variance Angiography as a Risk Reduction Measure in Peripheral Endovascular Interventions

Abstract

Introduction: Digital Variance Angiography (DVA) - that is based on the kinetic imaging technology - is a novel, patented X-ray image processing method visualizing contrast motion by calculating the variance of each pixel intensity in a recorded series of images. The image processing algorithm is built in a software that is able to generate DVA images from raw X-ray image series. Our aim was to determine the potential benefits of DVA in peripheral endovascular interventions. Methods: Two observational studies enrolled 66 patients undergoing lower limb X-ray angiography due to symptomatic peripheral arterial disease. A subgroup of 24 patients received carbon-dioxide (CO2) as contrast medium. We compared the signal-to-noise ratios (SNRs) of Digital Subtraction Angiography (DSA) and DVA image pairs. Visual quality comparisons were also performed by vascular specialists using an online questionnaire. Interrater agreement was characterized by percent agreement and Fleiss' kappa. Results: A total of 6814 regions of interest were selected on image pairs to calculate and compare SNRs. The ratio of SNR(DVA)/SNR(DSA) was calculated. DVA provided 3.3 times (median) higher SNR than DSA on angiograms obtained using iodinated contrast medium (ICM). The ratio was 3.0 times (median) higher in the images of the CO2 subgroup. In 69% of the ICM group comparisons it was judged that DVA provided higher quality images than DSA. Fleiss's kappa was 0.17 (p< 0.001). DVA was preferred over DSA in 85% of paired image comparisons in the CO2 subgroup. Fleiss's kappa was 0.27 (p< 0.001). Conclusion: In conclusion, DVA provides significantly higher image quality than the current reference standard DSA while performing catheter angiography with ICM or CO2. The higher image quality makes CO2 angiography more feasible for patients with renal insufficiency and iodine allergy. The significant SNR difference suggests a remarkable reduction of radiation and ICM exposure, thus ongoing studies are investigating the optimal protocols for low-dose DVA acquisition. Disclosure: The studies were supported by Kinepict Health Ltd