Kinetic Imaging in Lower Extremity Arteriography: Comparison to Digital Subtraction Angiography.

Purpose To compare the image quality produced by kinetic imaging in x-ray angiography and the current reference standard digital subtraction angiography (DSA). Materials and Methods This prospective observational crossover study enrolled 42 patients undergoing lower limb x-ray angiography between February and June 2017 (mean age, 68.7 years; age range, 49-89 years; 32 men [mean age, 67.1 years; age range, 49-89 years] and 10 women [mean age, 75 years; age range, 57-85 years]). Signal-to-noise ratios (SNRs) of DSA and kinetic image pairs were compared. Visual quality comparisons were also performed by specialists who used an online questionnaire. Interrater agreement was characterized by percent agreement and Fleiss k. Results A total of 1902 regions of interest were carefully selected in 110 image pairs to calculate and compare the SNRs. Median SNR in raw kinetic images was 3.3-fold and 2.3-fold higher than raw and postprocessed DSA images, respectively. A total of 232 pairs of raw and postprocessed kinetic images were compared. It was indicated that postprocessing improved the quality of kinetic images in 63.9% (2668 of 4176) of the comparisons. Interrater agreement was 75% and Fleiss k was 0.12 (P < .001). Also, 238 pairs of kinetic and DSA images were compared. Kinetic imaging was judged to have provided higher quality images than DSA in 69.0% (2462 of 3570) of the comparisons. The interrater agreement was 81% and Fleiss k was 0.17 (P < .001). Conclusion Kinetic imaging helps to view the same structures as digital subtraction angiography but offers better image quality. The improved signal-to-noise ratio suggests that this approach could reduce radiation exposure and improve the ability to view smaller vessels. © RSNA, 2018 Online supplemental material is available for this article.

Digital variance angiography allows about 70% decrease of DSA-related radiation exposure in lower limb X-ray angiography.

Our aim was to investigate whether the previously observed higher contrast-to-noise ratio (CNR) and better image quality of Digital Variance Angiography (DVA) - compared to Digital Subtraction Angiography (DSA) - can be used to reduce radiation exposure in lower limb X-ray angiography. This prospective study enrolled 30 peripheral artery disease patients (mean ± SD age 70 ± 8 years) undergoing diagnostic angiography. In all patients, both normal (1.2 µGy/frame; 100%) and low-dose (0.36 µGy/frame; 30%) protocols were used for the acquisition of images in three anatomical regions (abdominal, femoral, crural). The CNR of DSA and DVA images were calculated, and the visual quality was evaluated by seven specialists using a 5-grade Likert scale. For investigating non-inferiority, the difference of low-dose DVA and normal dose DSA scores (DVA30-DSA100) was analyzed. DVA produced two- to three-fold CNR and significantly higher visual score than DSA. DVA30 proved to be superior to DSA100 in the crural region (difference 0.25 ± 0.07, p < 0.001), and there was no significant difference in the femoral (- 0.08 ± 0.06, p = 0.435) and abdominal (- 0.10 ± 0.09, p = 0.350) regions. Our data show that DVA allows about 70% reduction of DSA-related radiation exposure in lower limb X-ray angiography, providing a potential new radiation protection tool for the patients and the medical staff.

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 ±â€¯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 ±â€¯0.06) was significantly higher than the DSA100 score (3.52 ±â€¯0.07, Wilcoxon p < 0.001), and the DVA50 score (3.64 ±â€¯0.13) was also significantly higher than the DSA50 score (3.01 ±â€¯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.