The effect of boosted injection of saline on contrast effect in angiography

To evaluate the effect of saline boost injections on angiographic contrast. Angiographic examinations were performed using a SIEMENS ArtisQ Celling (VD11E) system with syngo Workplace (VD20B) and a PRESS DUO elite autoinjector (Nemoto Kyorindo, Tokyo). Standard injection parameters, assuming non-selective angiography from the abdominal aortic bifurcation to the common femoral artery, were 5.0 mL/s for 2.0 s. Five boost conditions were assessed: injection speed of 5.0, 7.0, and 10.0 mL/s with total volumes of 5.0, 10.0, and 15.0 mL (1.0-3.0× standard), and 7.0 and 10.0 mL volumes corresponding to the amount delivered within 1.0 s. Time-enhancement curves (TECs) were generated from identical regions of interest placed in the proximal, middle, and distal portions of a vascular phantom to measure maximum signal intensity and enhancement duration. Additional quantitative analysis was performed using iFlow color-coded maps. Changes in the saline-flush boost volume resulted in minor differences compared with the baseline TECs. At a boost speed of 7.0 mL/s, maximum signal intensity increased by 7.2%, 8.1%, and 7.0% in the proximal, middle, and distal segments. At 10.0 mL/s, increases were 11.5%, 11.3%, and 11.1%, respectively. On iFlow analysis, the reference time-to-peak significantly shortened at 10.0 mL/s-3.49, 4.01, and 4.17 s-compared with 3.68, 4.22, and 4.26 s at baseline (p < 0.01). Boosting double-speed saline injection improved the efficiency of contrast agent delivery to distal regions. Further improvements in injection efficiency may reduce the required amount of contrast agent and the number of frames.