Quantifying iodine concentration in the normal bowel wall using dual-energy CT: Influence of Patient and Contrast Characteristics.

Abstract

Abstract Purpose: This study aimed to establish quantitative references of bowel wall iodine concentration (BWIC) using DECT. Methods: This single-center retrospective study included 248 patients with no history of gastrointestinal disease who underwent abdominal contrast-enhanced DECT between January and April 2022. The BWIC was normalized by the iodine concentration of upper abdominal organs (BWICorgan,) and the iodine concentration of the aorta (BWICaorta) Results: BWIC decreased from the stomach to the rectum (mean 2.16±0.63 vs. 2.19±0.63 vs. 2.1±0.58 vs. 1.67±0.47 vs. 1.31±0.4 vs. 1.18±0.34 vs. 0.94±0.26 mgI/mL for the stomach, duodenum, jejunum, ileum, right colon, left colon and rectum, respectively; P < 0.001). By multivariate analysis, BWIC was associated with a higher BMI (OR:1.01, 95%CI: 1.00–1.02, P < 0.001) and with a higher injected contrast dose (OR:1.51; 95%CI: 1.36–1.66, P < 0.001 and 2.06; 95%CI:1.88–2.26, P < 0.001 for 500 mgI/kg and 600 mgI/kg doses taking 400 mgI/kg dose as reference). The BWICorgan was shown independent from patients and contrast-related variables while the BWICaorta was not. Conclusion: BWIC concentration vary according to bowel segments and is dependent on the total iodine dose injected. It shall be normalized with the IC of the upper abdominal organs.