Validation of functional liver imaging scores (FLIS) derived from gadoxetic acid-enhanced MRI in patients with chronic liver disease and liver cirrhosis: the relationship between Child-Pugh score and FLIS.

OBJECTIVES: To validate the functional liver imaging score (FLIS) for prediction of hepatic function in gadoxetic acid-enhanced MRI. METHODS: We retrospectively identified 134 patients (88 men, 46 women; mean age, 58.8 years) between January 2015 and December 2018 with the following inclusion criteria: patients diagnosed with liver cirrhosis or chronic liver disease (CLD) who underwent gadoxetic acid-enhanced MRI. Three parameters on hepatobiliary phase images were evaluated for FLIS: liver parenchymal enhancement, biliary excretion, and signal intensity of the portal vein. Patients were classified as CLD (n = 11), Child-Pugh (CP) class A (n = 87), CP B (n = 22), or CP C (n = 14). We assessed the correlation between CP score and both FLIS and its components using Spearman rank correlation. Receiver operating characteristic (ROC) curve analysis was performed to demonstrate the cutoff value of FLIS for differentiating between CP classes. The associations between patient characteristics, serum markers, FLIS, and hepatic decompensation were evaluated with Cox proportional hazard models. RESULTS: FLIS and three FLIS parameters showed strong to very strong correlation with CP score (r = -0.60 to 0.82). ROC curve analysis showed that FLIS ≥ 5 was the optimal cutoff for prediction of CP class A or CLD (sensitivity, 83.7%; specificity, 94.4%; area under the curve [AUC], 0.93). FLIS < 5 was independently associated with the development of first hepatic decompensation in patients with CP A (HR, 50.0; 95% confidence interval, 6.2, 400.4). CONCLUSION: FLIS showed a strong correlation with hepatic function and can stratify the CP class. In addition, FLIS can help prediction for the development of first decompensation. KEY POINTS: • Functional liver imaging scores (FLIS) and its three parameters, derived from hepatobiliary phase image, have strong to very strong correlations with Child-Pugh (CP) scores. • FLIS can stratify patients with chronic liver disease or liver cirrhosis according to CP classification. • Low FLIS is an independent predictor for first hepatic decompensation in patients with CP class A.

Quantitative assessment of hepatic function: modified look-locker inversion recovery (MOLLI) sequence for T1 mapping on Gd-EOB-DTPA-enhanced liver MR imaging.

OBJECTIVES: To determine whether multislice T1 mapping of the liver using a modified look-locker inversion recovery (MOLLI) sequence on gadoxetic acid-enhanced magnetic resonance imaging (MRI) can be used as a quantitative tool to estimate liver function and predict the presence of oesophageal or gastric varices. METHODS: Phantoms filled with gadoxetic acid were scanned three times using MOLLI sequence to test repeatability. Patients with chronic liver disease or liver cirrhosis who underwent gadoxetic acid-enhanced liver MRI including MOLLI sequence at 3 T were included (n = 343). Pre- and postcontrast T1 relaxation times of the liver (T1liver), changes between pre- and postcontrast T1liver (ΔT1liver), and adjusted postcontrast T1liver (postcontrast T1liver-T1spleen/T1spleen) were compared among Child-Pugh classes. In 62 patients who underwent endoscopy, all T1 parameters and spleen sizes were correlated with varices. RESULTS: Phantom study showed excellent repeatability of MOLLI sequence. As Child-Pugh scores increased, pre- and postcontrast T1liver were significantly prolonged (P < 0.001), and ΔT1liver and adjusted postcontrast T1liver decreased (P < 0.001). Adjusted postcontrast T1liver and spleen size were independently associated with varices (R (2) = 0.29, P < 0.001). CONCLUSIONS: T1 mapping of the liver using MOLLI sequence on gadoxetic acid-enhanced MRI demonstrated potential in quantitatively estimating liver function, and adjusted postcontrast T1liver was significantly associated with varices. KEY POINTS: • T1 mapping using MOLLI sequence can be achieved within a breath-hold. • T1liver measured by MOLLI sequence provided excellent short-term repeatability. • Precontrast and postcontrast T1liver were significantly prolonged as Child-Pugh scores increased. • Adjusted postcontrast T1liver and spleen size were independently associated with varices.

Feasibility of Imaging-Based Quantitative Hepatic Function Assessment: Gd-EOB-DTPA-Enhanced Liver MR Imaging Combined with T1 Mapping.

OBJECTIVE: to investigate the feasibility of gadoxetic acid (Gd-EOB-DTPA) enhanced MRI combined with T1 mapping in quantitative hepatic function assessment. METHODS: this study retrospectively enrolled 94 patients with Gd-EOB-DTPA enhanced MRI combined with T1 mapping, divided into group A (grade A, n=73), group B (grade B, n=14) and group C (grade C, n=7) based on Child-Pugh classification. Liver T1 relaxation times on plain scan (T1P) and hepatocellular phase (T1E) were measured. Decrease in T1 (T1D) and the percentage of decrease in T1 (T1D%) were calculated as follows: T1D=T1P-T1E, T1D%= T1D/T1P×100%. The relationship between T1P, T1E, T1D, T1D% and liver function classification was analyzed. RESULTS: T1P, T1D, and T1D% in group A were significantly higher than those of group B and C. T1E in group A was lower than those of group B and C. T1D% was significantly different between group B and C. There was no significant difference in T1P, T1E, T1D between groups B and C. T1E was positively correlated with liver function levels, T1P and T1D had a negative correlation with liver function levels. T1P, T1E, T1D, T1D% were significantly different between cirrhotic and non-cirrhotic groups. T1D% of less than 70% suggests liver dysfunction. CONCLUSION: Gd-EOB-DTPA enhanced liver MRI combined with T1 mapping is feasible for quantitative assessment of hepatic function.

Determining the efficacy of functional liver imaging score (FLIS) obtained from gadoxetic acid-enhanced MRI in patients with chronic liver disease and liver cirrhosis: the relationship between Albumin-Bilirubin (ALBI) grade and FLIS.

PURPOSE: (1) To evaluate the efficacy of functional liver imaging score (FLIS) in predicting liver function on gadoxetic acid-enhanced MRI in patients with chronic liver disease (CLD) or liver cirrhosis (LC) and its relationship with ALBI grade. (2) To assess the intra-reader reliability and interreader agreement of readers with different levels of experience in abdominal imaging of FLIS. METHODS: We retrospectively included 131 patients (70 men, 61 women; mean ± SD, 53.7 ± 14.6 years) with CLD and LC who underwent GA-enhanced MRI between November 2019 and March 2022. FLIS was assigned as a result of the sum of three hepatobiliary phase (HBP) images features, each scored 0-2: liver parenchymal enhancement, biliary contrast excretion, and portal vein sign. FLIS was calculated using HPB images independently by three radiologists with different experience. In addition, 50 randomly selected patients were reviewed a second time by a reader to assess intra-reader reliability. Patients were divided into the following three groups according to the albumin-bilirubin (ALBI) grade: ALBI grade 1, 2, and 3. We evaluated the correlation between ALBI grade and both FLIS and its parameters using Spearman's rank correlation for each reader. Receiver operating characteristic (ROC) curve analysis was performed to show the optimal cut-off value of FLIS to distinguish between ALBI grades. Intra-reader reliability and inter-reader agreement were evaluated by intraclass correlation coefficient (ICC). RESULTS: FLIS and three FLIS parameters showed very strong correlation with ALBI grade for each readers (r = - 0.843 to 0.976, - 0.831 to 0.962, and - 0.819 to 0.902, respectively). ROC curve analysis showed that FLIS ≥ 5 was the optimal cutoff for prediction of ALBI grade 1 for each readers (sensitivity, 83.7% to 95.4%; specificity, 82.6% to 87%; accuracy, 88.6% to 93.6% and area under the curve (AUC), 0.882 to 0.917), and FLIS ≤ 3 was the optimal cutoff for distinguish ALBI grade 3 from other grades for each readers (sensitivity, 100%; specificity, 95.2% to 96%; accuracy, 95.4% to 96.2% and AUC, 0.974 to 0.994). Intra-reader reliability (ICC = 0.95; 95% CI 0.93-0.96) and inter-reader agreement (ICC = 0.85 to 0.90; 95% CI 0.82-0.97) for FLIS were excellent. CONCLUSION: FLIS showed a very correlation with hepatic function level and can stratify the ALBI grades. This feature has demonstrated the potential of FLIS to be excellent radiological tools for predicting of liver function of CLD and LC patients in clinical practice. Also, the excellent agreement of FLIS among readers with different levels of experience indicates that it can be used with high accuracy and reproducibility regardless of experience.

Model and methods to assess hepatic function from indocyanine green fluorescence dynamical measurements of liver tissue.

The indocyanine green (ICG) clearance, presented as plasma disappearance rate is, presently, a reliable method to estimate the hepatic "function". However, this technique is not instantaneously available and thus cannot been used intra-operatively (during liver surgery). Near-infrared spectroscopy enables to assess hepatic ICG concentration over time in the liver tissue. This article proposes to extract more information from the liver intensity dynamics by interpreting it through a dedicated pharmacokinetics model. In order to account for the different exchanges between the liver tissues, the proposed model includes three compartments for the liver model (sinusoids, hepatocytes and bile canaliculi). The model output dependency to parameters is studied with sensitivity analysis and solving an inverse problem on synthetic data. The estimation of model parameters is then performed with in-vivo measurements in rabbits (El-Desoky et al. 1999). Parameters for different liver states are estimated, and their link with liver function is investigated. A non-linear (Michaelis-Menten type) excretion rate from the hepatocytes to the bile canaliculi was necessary to reproduce the measurements for different liver conditions. In case of bile duct ligation, the model suggests that this rate is reduced, and that the ICG is stored in the hepatocytes. Moreover, the level of ICG remains high in the blood following the ligation of the bile duct. The percentage of retention of indocyanine green in blood, which is a common test for hepatic function estimation, is also investigated with the model. The impact of bile duct ligation and reduced liver inflow on the percentage of ICG retention in blood is studied. The estimation of the pharmacokinetics model parameters may lead to an evaluation of different liver functions.