Non-invasive assessment of cirrhosis using multiphasic dual-energy CT iodine maps: correlation with model for end-stage liver disease score

Purpose: To determine whether multiphasic dual­energy (DE) CT iodine quantitation correlates with the severity of chronic liver disease. Methods: We retrospectively included 40 cirrhotic and 28 non-cirrhotic patients who underwent a multiphasic liver protocol DECT. All three phases (arterial, portal venous (PVP), and equilibrium) were performed in DE mode. Iodine (I) values (mg I/ml) were obtained by placing regions of interest in the liver, aorta, common hepatic artery, and portal vein (PV). Iodine slopes (λ) were calculated as follows: (Iequilibrium–Iarterial)/time and (Iequilibrium–IPVP)/time. Spearman correlations between λ and MELD scores were evaluated, and the area under the curve of the receiver operating characteristic (AUROC) was calculated to distinguish cirrhotic and non-cirrhotic patients. Results: Cirrhotic and non-cirrhotic patients had significantly different λequilibrium-arterial [IQR] for the caudate (λ = 2.08 [1.39–2.98] vs 1.46 [0.76–1.93], P = 0.007), left (λ = 2.05 [1.50–2.76] vs 1.51 [0.59–1.90], P = 0.002) and right lobes (λ = 1.72 [1.12–2.50] vs 1.13 [0.41–0.43], P = 0.003) and for the PV (λ = 3.15 [2.20–5.00] vs 2.29 [0.85–2.71], P = 0.001). λequilibrium-PVP were significantly different for the right (λ = 0.11 [− 0.45–1.03] vs − 0.44 [− 0.83–0.12], P = 0.045) and left lobe (λ = 0.30 [− 0.25–0.98] vs − 0.10 [− 0.35–0.24], P = 0.001). Significant positive correlations were found between MELD scores and λequilibrium-arterial for the caudate lobe (ρ = 0.34, P = 0.004) and λequilibrium-PVP for the caudate (ρ = 0.26, P = 0.028) and right lobe (ρ = 0.33, P = 0.007). AUROC in distinguishing cirrhotic and non-cirrhotic patients were 0.72 (P = 0.002), 0.71 (P = 0.003), and 0.75 (P = 0.001) using λequilibrium-arterial for the left lobe, right lobe, and PV, respectively. The λequilibrium-PVP AUROC of the right lobe was 0.73 (P = 0.001). Conclusion: Multiphasic DECT iodine quantitation over time is significantly different between cirrhotic and non-cirrhotic patients, correlates with the MELD score, and it could potentially serve as a non-invasive measure of cirrhosis and disease severity with acceptable diagnostic accuracy.