Improving lower-extremity artery depiction and diagnostic confidence using dual-energy technique and popliteal artery monitoring in dual-low dose CT angiography

To assess the utility of dual-energy CT scanning (DECTs) with popliteal artery (PA) monitoring in dual low-dose (radiation and contrast) lower-extremity CT angiography (LE-CTA). 135 patients undergoing LE-CTA were prospectively included and divided into three groups of 45 each. Group-A: conventional scanning, 105 mL of contrast, abdominal aorta monitoring; Group-B: low-dose DECTs, 95 mL of contrast, AA monitoring; Group-C: low-dose DECTs, 85 mL of contrast, PA monitoring. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), as well as their elevations at seven arteries, were evaluated. Two radiologists conducted subjective assessments of overall image quality and vascular diagnosis in three arterial segments. They also recorded the visible branch grading in the lower-knee segment (LKS). Group-C reduced contrast and effective doses by 19.04% and 12.62%, respectively, compared to Group-A (P < 0.001). Group-C had the best SNR and CNR for four LKS arteries. Regarding SNR and CNR elevations, Group-C outperformed Group-B in distal arteries beyond the PA. In the LKS, Group-C performed best for subjective overall image quality, visible branch grading, and diagnostic confidence, as well as the inter-observer diagnostic consistency, followed by Group-B and Group-A (P < 0.001). DECTs with PA monitoring provides excellent depiction of lower-extremity arteries under dual low-dose conditions.