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 and DVA videos was also compared.

RESULTS

DVA provided more than two-fold SNR, the median SNR/SNR ratio was 2.06 (100 %) and 2.25 (50 %). In the visual evaluation, the DVA score (3.73 ± 0.06) was significantly higher than the DSA score (3.52 ± 0.07, Wilcoxon p < 0.001), and the DVA score (3.64 ± 0.13) was also significantly higher than the DSA 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 vs DSA), it had no effect on the DVA score (DVA vs DVA). There was no statistical difference between the DSA and DVA scores. Evaluators preferred the diagnostic value of DVA to DSA 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.