To evaluate the feasibility of aortoiliac CT-Angiography (CTA) using dual-source photon-counting detector (PCD)-CT with minimal iodine dose. This IRB-approved, single-center prospective study enrolled patients with indications for aortoiliac CTA from December 2022 to March 2023. All scans were performed using a first-generation dual-source PCD-CT. Images were acquired with fast pitch and full spectral capabilities (collimation 144×0.4mm). The contrast protocol included a mixture of sodium chloride and iodinated contrast agent (Iopromide, total iodine dose: 9.5-9.8g). Virtual monoenergetic images (VMIs) were reconstructed at 40, 50, 60, and 68keV. Two blinded radiologists evaluated image quality on a 4-point scale. Attenuation was measured across eight regions in the aorta and iliac arteries, and contrast-to-noise ratio (CNR) was calculated. Statistical comparisons were performed using repeated measures ANOVA and Bonferroni post-hoc tests. The final cohort consisted of 39 subjects (mean age: 69.6±9.6years; 30.8% female). VMI at 40keV provided significantly higher attenuation: 478±114 HU, compared to 50keV (331±74 HU), 60keV (241±51 HU), and 68keV (190±48 HU) (p<0.01). This translated in increased CNR for 40keV reconstructions (11.8±3.9), followed by 50keV (9.1±3.0), 60keV (7.0±2.3), and 68keV (6.1±1.9) (p<0.01). Subjective image quality was rated excellent at 40keV (4 [3,4]), though associated with highest noise (38±7.4 HU, p=0.02). Aortoiliac CTA using dual-source PCD-CT at 40keV achieved high attenuation and CNR, enabling effective imaging with only 9.8g of iodine.
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