The Effect of Contrast Media Formulations with Different Iodine Preparation Concentrations at a Constant Iodine...

The effect of iodine preparation concentration on vascular attenuation during computed tomography angiography (CTA) is a topic of controversy. Iodine-based contrast media (CM) formulations are used in different iodine preparation concentrations and, accordingly, their viscosity varies considerably. This study aimed to investigate the influence of CM formulations with different iodine preparation concentrations on image quality under conditions of a constant iodine dose and constant iodine delivery rate (IDR) in low-dose, low-kVp thoracoabdominal CTA using a standardized animal model.

A cohort of six healthy Göttingen minipigs underwent three low-dose CTA scans (90 kV, CTDIvol = 1.7 ± 0.5 mGy) using three CM formulations with different iodine preparation concentrations (300, 370, and 400 mgI/mL). All formulations were injected at a constant IDR of 1.3 gI/s and at a constant total iodine dose of 252 mgI/kg in a randomized sequence. Quantitative image quality was assessed using contrast-to-noise ratio (CNR) and image similarity metrics. Subjective image quality was evaluated by two experienced radiologists using a 5-point Likert scale.

No significant differences in CNR were observed between the CM formulations (300 mgI/mL = 15.6 ± 2.8, 370 mgI/mL= 15.0 ± 3.8, 400 mgI/mL = 15.0 ± 4.9). The subjective image quality evaluations revealed no significant differences between the groups, except for a slight tendency towards higher ratings for the 300 mgI/mL formulation for sharpness (300 mgI/mL=5 (4.3-5), 370 mgI/mL = 4 (4-5), 400 mgI/mL = 4 (4-5)) and diagnostic acceptability (300 mgI/mL = 4 (3-4), 370 mgI/mL = 3.5 (3-4), 400 mgI/mL = 3.5 (2.3-4)).

Under the investigated conditions of constant iodine delivery rate and constant iodine dose, CM formulations with iodine preparation concentrations ranging from 300 to 400 mgI/mL do not lead to significant differences in objective or subjective image quality in low-dose, low-kVp CTA. These findings represent a proof-of-concept under controlled experimental conditions.

· A standardized animal model allowed a controlled analysis of CM formulations with different iodine preparation concentrations.. · At a constant IDR and total iodine dose, image quality remained comparable across the investigated CM formulations.. · A higher iodine preparation concentration did not result in a measurable image quality benefit with a fixed IDR..

· Holtkamp M, Jost G, Salhöfer L et al. The Effect of Contrast Media Formulations with Different Iodine Preparation Concentrations at a Constant Iodine Delivery Rate in Low-kV CT Angiography: An Experimental Animal Study. Rofo 2026; DOI 10.1055/a-2818-5244.