Initial evidence of a 50% reduction of contrast media using digital variance angiography in endovascular carotid interventions

Purpose In previous clinical studies Digital Variance Angiography (DVA) provided higher signal-to-noise ratio (SNR) and better image quality than Digital Subtraction Angiography (DSA). Our aim was to investigate whether this quality reserve of DVA provides an opportunity for the reduction of iodinated contrast media (ICM) in carotid X-ray angiography (CXA). Method Our prospective study enrolled 26 patients (67.0 ± 8.1 years) undergoing carotid percutaneous transluminal angioplasty. The SNR of DSA and DVA image pairs obtained by a standard (100 %, 6 mL ICM) or a low-dose (50 %, 3 mL ICM) protocol were compared. Visual evaluation of all images was performed by five specialists using a 5-grade rating scale. The quality of DSA 100 and DVA 50 videos was also compared. Results DVA provided more than two-fold SNR, the median SNR DVA /SNR DSA ratio was 2.06 (100 %) and 2.25 (50 %). In the visual evaluation, the DVA 100 score (3.73 ± 0.06) was significantly higher than the DSA 100 score (3.52 ± 0.07, Wilcoxon p < 0.001), and the DVA 50 score (3.64 ± 0.13) was also significantly higher than the DSA 50 score (3.01 ± 0.17, Wilcoxon p < 0.001). While the low-dose protocol significantly decreased the DSA score (Mann-Whitney p < 0.01, DSA 100 vs DSA 50 ), it had no effect on the DVA score (DVA 100 vs DVA 50 ). There was no statistical difference between the DSA 100 and DVA 50 scores. Evaluators preferred the diagnostic value of DVA 50 to DSA 100 videos in 61% of comparisons, the interrater agreement was 69 % (Fleiss' kappa 0.35, p < 0.001) Conclusions Our data show that DVA allows a substantial (50 %) ICM reduction in CXA without affecting the quality and diagnostic value of angiograms.