Quantitative contrast-enhanced ultrasonography in the diagnosis and grading of hepatic steatosis in brain-dead donors.

Background: The presence of hepatic steatosis (HS) is a crucial histological parameter for evaluating the suitability of liver transplantation. However, to date, no studies have used contrast-enhanced ultrasonography (CEUS) to diagnose and grade HS in brain-dead donors. This study aimed to detect and quantify hepatic microcirculatory perfusion in brain-dead donors using CEUS and to assess the utility of CEUS in the diagnosis and grading of HS.

Methods: This prospective study enrolled 88 livers from brain-dead donors (44 with HS and 44 without HS) aged ≥18 years between June 2020 and January 2024. The donors had a mean age of 45.42±9.59 years, and 70 were male (79.5%). CEUS was conducted on the livers of the brain-dead donors 24 h before organ procurement, and time-intensity curves were generated. The main measures included the arrival time, time-to-peak, peak intensity of the hepatic artery (PIHA), peak intensity of the portal vein (PIPV), and peak intensity of the liver parenchyma (PILP), and hepatorenal index (HRI). Logistic regression analyses were used to identify the significant factors associated with HS, and the areas under the curve (AUC) of the receiver operating characteristic curves were used to evaluate diagnostic performance.

Results: The PIHA (P<0.001), PIPV (P<0.001), and PILP (P=0.001) were significantly shorter in the steatosis group than the non-steatosis group. The one-way analysis of variance revealed significant decreases in the PIHA (P<0.001), PIPV (P<0.001), and PILP (P<0.001) as HS grades increased. The multivariate regression analysis indicated that the PIHA was an independent factor for both HS [odds ratio (OR) =0.97, 95% confidence interval (CI): 0.94-0.99, P=0.01] and moderate-to-severe HS (OR =0.96, 95% CI: 0.93-0.99, P=0.009). The AUC values of the PIHA and HRI for diagnosing moderate-to-severe HS were 0.88 and 0.69, respectively. The optimal cut-off value of the PIHA for diagnosing moderate-to-severe HS was 173.04, with a sensitivity of 92.9% (13 of 14 livers), specificity of 68.9% (51 of 74 livers), and positive and negative predictive values of 36.1% and 98.1%, respectively.

Conclusions: CEUS showed promising results in the diagnosis and grading of HS in brain-dead donors. The PIHA, a CEUS-derived parameter, could serve as a diagnostic tool for moderate-to-severe HS.