Predictive Value of Unenhanced Computerized Tomography for Detecting Hepatosteatosis in Living Liver Donors

Diagnostic Accuracy of CT for the Detection of Hepatic Steatosis: A Systematic Review and Meta-Analysis

Background CT plays an important role in the opportunistic identification of hepatic steatosis. CT performance for steatosis detection has been inconsistent across various studies, and no clear guidelines on optimum thresholds have been established. Purpose To conduct a systematic review and meta-analysis to assess CT diagnostic accuracy in hepatic steatosis detection and to determine reliable cutoffs for the commonly mentioned measures in the literature. Materials and Methods A systematic search of the PubMed, Embase, and Scopus databases (English-language studies published from September 1977 to January 2024) was performed. Studies evaluating the diagnostic accuracy of noncontrast CT (NCCT), contrast-enhanced (CECT), and dual-energy CT (DECT) for hepatic steatosis detection were included. Reference standards included biopsy, MRI proton density fat fraction (PDFF), or NCCT. In several CECT and DECT studies, NCCT was used as the reference standard, necessitating subgroup analysis. Statistical analysis included a random-effects meta-analysis, assessment of heterogeneity with use of the I2 statistic, and meta-regression to explore potential sources of heterogeneity. When available, mean liver attenuation, liver-spleen attenuation difference, liver to spleen attenuation ratio, and the DECT-derived fat fraction for hepatic steatosis diagnosis were assessed. Results Forty-two studies (14 186 participants) were included. NCCT had a sensitivity and specificity of 72% and 88%, respectively, for steatosis (>5% fat at biopsy) detection and 82% and 94% for at least moderate steatosis (over 20%-33% fat at biopsy) detection. CECT had a sensitivity and specificity of 66% and 90% for steatosis detection and 68% and 93% for at least moderate steatosis detection. DECT had a sensitivity and specificity of 85% and 88% for steatosis detection. In the subgroup analysis, the sensitivity and specificity for detecting steatosis were 80% and 99% for CECT and 84% and 93% for DECT. There was heterogeneity among studies focusing on CECT and DECT. Liver attenuation less than 40-45 HU, liver-spleen attenuation difference less than -5 to 0 HU, and liver to spleen attenuation ratio less than 0.9-1 achieved high specificity for detection of at least moderate steatosis. Conclusion NCCT showed high performance for detection of at least moderate steatosis. © RSNA, 2024 Supplemental material is available for this article.

Outcome of Living-Donor Liver Transplantation Using Grafts from Donors Treated for Fatty Liver

Background

The aim of this study was to determine the efficacy of treating donors’ fatty liver (FL) and to assess early graft function in recipients who received treated FL grafts in living-donor liver transplantation (LDLT).

Material/Methods

Data were collected for adult-to-adult LDLTs. Donors diagnosed with FL (FL group) received diet–exercise and pharmacological treatment. The perioperative findings and early transplanted graft function were compared with those of donors without FL (non-FL group) during the same period.

Results

Of 30 donors, 8 were determined to have FL. The median duration of treatment for FL was 58 days. The liver-to-spleen attenuation ratios on CT scan in the FL group were significantly improved after treatment: 0.95 (0.62–1.06) to 1.2 (1.12–1.46) (P=0.003). Liver biopsy prior to donor surgery showed ≤10% fatty infiltration. Postoperative laboratory findings of the donors in the FL group were comparable to those in the non-FL group: maximum alanine transaminase (189.6±94.7 IU/L vs. 196.8±57.4) and maximum total bilirubin (2.2±1.1 mg/dL vs. 1.7±0.5 mg/dL). No major complications were observed after donor hepatectomy in either group. There were no significant differences between the 2 groups in early graft function, as evaluated by laboratory data, ascites volume, and bile production 2 weeks postoperatively. Graft and patient survival were 100% in both groups at 3 months.

Conclusions

Preoperative intentional treatment for FL was effective. Early graft function and donor postoperative course were comparable in the 2 groups. These results suggest that well-treated steatotic grafts can be used without jeopardizing donor safety.