Quantitative Enhancement Parameters of Dual-Layer Detector Spectral CT in the Assessment of Hepatic Functional...

Objective To evaluate the value of dual-layer spectral CT-derived iodine concentration (IC) and extracellular volume (ECV) in the portal venous phase in assessing hepatic functional reserve. Methods A total of 24 patients who underwent triphasic abdominal spectral CT enhancement scanning between January 2020 and August 2022 were retrospectively enrolled.IC and ECV maps were generated from spectral base data of the portal venous phase,and IC and ECV values were measured in the left lobe,right lobe,and caudate lobe of the liver.Differences in parameters among hepatic lobes were compared by the Kruskal-Wallis test.Pearson or Spearman correlation analysis was performed to assess the relationships of IC and ECV with parameters of the indocyanine green (ICG) clearance test.The key parameters analyzed included the ICG retention rates at 5 min (ICGR5),at 10 min (ICGR10),at 15 min (ICGR15),and the ICG clearance rate (ICG-CR).On the basis of correlation results,multivariate linear regression models were constructed. Results ECV in the right hepatic lobe showed negative correlations with ICGR5 (r=-0.48,P=0.019),ICGR10 (r=-0.48,P=0.019),and ICGR15 (r=-0.47,P=0.021) and a positive correlation with ICG-CR (r=0.48,P=0.019).IC in the right hepatic lobe also showed negative correlations with ICGR5 (r=-0.52,P=0.009),ICGR10 (r=-0.52,P=0.009),and ICGR15 (r=-0.53,P=0.008) and a positive correlation with ICG-CR (r=0.52,P=0.009).IC in the right hepatic lobe demonstrated the best predictive performance for ICGR5 (y=0.62-0.16×IC,R²=0.26,P=0.011) and ICG-CR (y=0.09-0.07×IC,R²=0.32,P=0.004),whereas ECV was not selected in the multivariate regression model. Conclusion The dual-layer spectral CT-derived IC in the portal venous phase of the right hepatic lobe demonstrates significant clinical relevance with hepatic functional reserve,potentially serving as a non-invasive imaging biomarker for liver function assessment.