Quantification of liver extracellular volume using dual-energy CT for ruling out high-risk varices in cirrhosis

Purpose: To determine the performance of quantification of liver extracellular volume fraction (fECV) using dual-energy CT (DECT) compared with CT imaging for ruling out high-riskesophageal varices(HRV) in cirrhotic patients. Methods: We retrospectively analyzed 229 cirrhotic patients (training [n = 159] and internal validation cohorts [n = 70]) who underwent dual-source DECT, serum marker assessment, and esophagogastroduodenoscopy (EGD) from 2017 to 2020. The fECV score was measured using iodine maps from 3-minute delayed, equilibrium-phase images at 100/140 Sn kVp. The association of CT parameters and serum markers with HRV was investigated. Criteria combining the fECV score (<= 25.1%) or CT imaging with platelet count (> 150,000/mm(3)) were created and compared to rule out HRV. Results: In the training cohort, the fECV score (odds ratio (OR), 1.20; 95% confidence interval (CI), 1.09, 1.32) and CT imaging (OR, 28.21; 95% CI, 9.31, 85.93) were independent predictors of HRV, along with platelet count (OR, 0.85 and 0.78). Criteria combining the fECV score with platelet count showed significantly better performance than those combining CT imaging with platelet count in ruling out HRV (p < 0.001). Applying the criteria could have safely avoided an additional 10.7% and 8.6% of EGDs in the training and validation cohorts, respectively, achieving a final value of 36.5% and 35.7% spared EGDs (0 HRV missed) compared to CT imaging with platelet count. Conclusions: The combined DECT-based fECV score with platelet count is useful for ruling out HRV and can safely avoid more EGDs than CT imaging with platelet count.