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

Abstract

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 DSA100 and DVA50 videos was also compared. Results: DVA provided more than two-fold SNR, the median SNRDVA/SNRDSA ratio was 2.06 (100 %) and 2.25 (50 %). In the visual evaluation, the DVA100 score (3.73 ± 0.06) was significantly higher than the DSA100 score (3.52 ± 0.07, Wilcoxon p < 0.001), and the DVA50 score (3.64 ± 0.13) was also significantly higher than the DSA50 score (3.01 ± 0.17, Wilcoxon p < 0.001). While the low-dose protocol significantly decreased the DSA score (Mann-Whitney p < 0.01, DSA100 vs DSA50), it had no effect on the DVA score (DVA100 vs DVA50). There was no statistical difference between the DSA100 and DVA50 scores. Evaluators preferred the diagnostic value of DVA50 to DSA100 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.

Keywords

• Digital variance angiography
• Digital subtraction angiography
• Carotid artery disease
• Iodinated contrast media
• Dose management
• Safety