# Three-Dimensional Volumetric Iodine Mapping of the Liver Segment Derived from Contrast-Enhanced Dual-Energy CT for the Assessment of Hepatic Cirrhosis

## TL;DR

This study uses 3D iodine mapping from CT scans to assess liver cirrhosis by comparing iodine concentration differences and extracellular volume in cirrhotic and non-cirrhotic patients.

## Contribution

Introduces 3D volumetric iodine mapping from DECT to evaluate hepatic cirrhosis with segment-specific analysis.

## Key findings

- Iodine concentration differences between PVP and EP were significantly smaller in cirrhotic patients.
- ECV fraction in the left medial liver segment was higher in cirrhotic patients.
- Reduced iodine concentration difference suggests portal flow reduction and fibrosis-related changes in cirrhosis.

## Abstract

Objective: This study aimed to evaluate the hepatic volume, iodine concentration, and extracellular volume (ECV) of each hepatic segment in cirrhotic patients using three-dimensional (3D) volumetric iodine mapping of the liver segment derived from contrast-enhanced dual-energy CT (DECT) superimposed on extracted color-coded CT liver segments in comparison with non-cirrhotic patients. Methods: The study population consisted of 66 patients, 34 with cirrhosis and 32 without cirrhosis. Using 3D volumetric iodine mapping of the liver segment derived from contrast-enhanced DECT superimposed on extracted color-coded CT liver segments, the volume and iodine concentration of each hepatic segment in the portal venous phase (PVP) and equilibrium phase (EP), the difference in iodine concentration between PVP and EP (ICPVP-liver—ICEP-liver), and ECV fractions were compared between cirrhotic and non-cirrhotic groups. Results: The iodine concentration was not significantly different in all hepatic segments between the cirrhotic and non-cirrhotic groups. Conversely, the difference in iodine concentration between PVP and EP (ICPVP-liver—ICEP-liver) was significantly smaller in the cirrhosis group than in the non-cirrhosis group for all hepatic segments (p < 0.001). The ECV fraction of the left medial segment was significantly higher in the cirrhosis group than in the non-cirrhotic group ([26.4 ± 7.6] vs. [23.1 ± 5.1]; p < 0.05). Conclusions: The decreased difference in iodine concentration between PVP and EP calculated from 3D volumetric iodine mapping of the liver segment using DECT may be a clinically useful indicator for evaluating patients with compensated cirrhosis, suggesting a combined effect of a reduced portal venous flow and increased interstitial space associated with fibrosis.