Feasibility of very low iodine dose aortoiliac CT angiography using dual-source photon-counting detector CT

• Published in: European journal of radiology Vol. 183; p. 111919
• Main Authors: Oechsner, Tim, Soschynski, Martin, Schlett, Christopher L., Krauss, Tobias, Schupppert, Christopher, Müller-Peltzer, Katharina, Vecsey-Nagy, Milán, Kravchenko, Dmitrij, Varga-Szemes, Ákos, Emrich, Tilman, Scheu, Raphael, Taron, Jana, Bamberg, Fabian, Hagar, Muhammad Taha
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.02.2025
• Subjects: Aged; Aorta; Aorta - diagnostic imaging; Computed Tomography Angiography - methods; Contrast Media - administration & dosage; Contrast medium; Feasibility Studies; Female; Humans; Iliac Artery - diagnostic imaging; Iodine; Iohexol - administration & dosage; Iohexol - analogs & derivatives; Male; Middle Aged; Photon-counting; Photons; Prospective Studies; Radiation Dosage; Radiographic Image Interpretation, Computer-Assisted; Photon-counting; CT; Aorta; Contrast medium; Iodine
• ISSN: 0720-048X; 1872-7727; 1872-7727
• DOI: 10.1016/j.ejrad.2025.111919

•PCD-CT enables aortoiliac CTA with < 10 g iodine dose with high image quality.•VMIs at 40 keV provided 478 HU and 11.8 CNR, exceeding necessary thresholds.•Increased noise was observed at lower keV levels, yet did not affect diagnostic quality. 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 × 0.4 mm). The contrast protocol included a mixture of sodium chloride and iodinated contrast agent (Iopromide, total iodine dose: 9.5–9.8 g). Virtual monoenergetic images (VMIs) were reconstructed at 40, 50, 60, and 68 keV. 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 ± 9.6 years; 30.8 % female). VMI at 40 keV provided significantly higher attenuation: 478 ± 114 HU, compared to 50 keV (331 ± 74 HU), 60 keV (241 ± 51 HU), and 68 keV (190 ± 48 HU) (p < 0.01). This translated in increased CNR for 40 keV reconstructions (11.8 ± 3.9), followed by 50 keV (9.1 ± 3.0), 60 keV (7.0 ± 2.3), and 68 keV (6.1 ± 1.9) (p < 0.01). Subjective image quality was rated excellent at 40 keV (4 [3,4]), though associated with highest noise (38 ± 7.4 HU, p = 0.02). Aortoiliac CTA using dual-source PCD-CT at 40 keV achieved high attenuation and CNR, enabling effective imaging with only 9.8 g of iodine.