Quantitative Assessment of Hepatic Steatosis Using Contrast-Enhanced CT in the Venous Phase: A Study at Pranangklao Hospital

Abstract

Background: This retrospective study aimed to find a way to reduce patient radiation exposure during abdominal CT scans by eliminating the non-contrast phase. It investigated whether parameters from the venous phase CT scan alone could accurately diagnose hepatic steatosis.
Objective: To assess the diagnostic accuracy of venous phase CT parameters—liver attenuation, liver-spleen difference (LSD), and focal fat sparing—for detecting hepatic steatosis, aiming to reduce radiation exposure by omitting non-contrast phase.
Methods: Researchers analyzed data from 213 patients who had undergone both non-contrast and venous phase CT scans. The patients were divided into two groups: those with fatty liver and those without, based on their non-contrast CT results. The study then evaluated the diagnostic performance of three venous phase parameters, using standard metrics like sensitivity and specificity.
Results: Venous phase LSD less than -20 HU offered the highest diagnostic accuracy, with a sensitivity of 77.8% and a specificity of 97.1%. While liver attenuation less than 110 HU had high sensitivity (99.1%), its specificity was low (23.8%). Focal fat sparing, observed in 49.1% of fatty liver cases, was associated with significantly lower liver attenuation, suggesting more severe steatosis.
The study also found that the optimal cutoff thresholds for the population were an LSD of less than -13 HU and a liver attenuation of less than 89 HU, which improved both sensitivity and specificity more effectively than the standard values.
Conclusions: Parameters from the venous phase image, specifically an LSD value less than −13 HU and a liver attenuation less than 89 HU, are highly effective for diagnosing hepatic steatosis at Phranangklao Hospital. They can suitably replace non-contrast phase scanning, thereby reducing the radiation dose received by patients.