Indocyanine green clearance test (using spectrophotometry) and its correlation with model for end stage liver disease (MELD) score in Indian patients with cirrhosis of liver

Predictive Value of Preoperative ICG-R15 Testing in Post-hepatectomy Liver Failure Following Major Liver Resection: Indian Experience

Surgical resection stands as the preeminent therapeutic approach for both primary hepatocellular carcinoma and metastatic liver malignancies. Its efficacy is contingent upon the attainment of a comprehensive excision while ensuring a sufficient future liver remnant (FLR). However, post-hepatectomy liver failure (PHLF) remains a significant challenge, particularly in patients with preexisting liver disease. The present study aims to investigate the predictive value of the preoperative indocyanine green retention test at 15 min (ICG-R15) in identifying patients at risk of PHLF following major liver resection. This retrospective review focused on patients who underwent the ICG-R15 test before major liver resection between August 2021 and January 2023. All patients underwent standard preoperative evaluation and staging. Patients with primary or metastatic liver cancer planned for major resection and undergoing ICG-R15 were included in the study. Patients with elevated serum bilirubin (> 3 mg/dl) and those not undergoing liver resection or minor liver resection (< 3 segments) were excluded from the study. PHLF was defined by the International Study Group of Liver Surgery (ISGLS) criteria. Follow-up was performed to identify 90-day morbidity. Using univariate and multivariate logistic regression analyses, we confirmed independent risk parameters that predicted postoperative major complications and severe PHLF. The study included 72 patients who underwent preoperative ICG-R15 testing prior to major liver resection. PHLF occurred in 28 patients (38.9%), with 24 patients (33.3%) classified as severity score B and 3 patients (4.16%) had severity score C. Univariate analysis revealed future liver remnant (FLR), ICG-R15, and blood transfusion as predictors of PHLF. Multivariate analysis confirmed FLR (p = 0.019) and ICG-R15 (p = 0.032) as significant predictors. Receiver operating characteristic curve analysis yielded an area under the curve of 0.642 for ICG-R15 in predicting PHLF. An optimal cut-point of 7.5 was determined. Our study highlights the importance of preoperative risk assessment of liver function evaluation using the ICG-R15 test, to predict the risk of PHLF following liver resection. Implementing appropriate interventions, especially in patients with borderline FLR, can improve surgical outcomes and enhance patient safety. Further research and prospective studies are essential to refine risk prediction models and improve rates of PHLF after liver resections.

Diagnostic Accuracy of Indocyanine Green Clearance Test for Different Stages of Liver Fibrosis and Cirrhosis

(1) Background: This study aimed to correlate the indocyanine green clearance (ICG) test with histopathological grades of liver fibrosis and liver cirrhosis to assess its diagnostic accuracy in differentiating normal liver parenchyma from liver fibrosis and liver cirrhosis. (2) Methods: A total of 82 patients who received a histopathological liver examination, imaging, and ICG test within three months were included in this retrospective study. The histopathological level of fibrosis was graded using the Ishak scoring system, and the patients were divided into five categories: no liver fibrosis (NLF), mild liver fibrosis (MLF), advanced liver fibrosis (ALF), severe liver fibrosis (SLF), and liver cirrhosis (LC). The non-parametric Kruskal-Wallis test with post hoc pairwise comparison utilizing Mann-Whitney U tests and Bonferroni adjustment was used to analyze differences in the ICG test results between the patient groups. Cross correlation between the individual fibrosis/cirrhosis stages and the score of the ICG test was performed, and the sensitivity, specificity, and positive and negative predictive values were calculated for each model predicting liver fibrosis/cirrhosis. (3) Results: A significant difference (p ≤ 0.001) between stages of NLF, LF, and LC was found for the ICG parameters (ICG plasma disappearance rate (ICG-PDR) and ICG retention percentage at 15 min (ICG-R15)). The post hoc analysis revealed that NLF significantly differed from SLF (ICG-PDR: p = 0.001; ICG-R15: p = 0.001) and LC (ICG-PDR: p = 0.001; ICG-R15: p = 0.001). ALF also significantly differed from SLF (ICG-PDR: p = 0.033; ICG-R15: p = 0.034) and LC (ICG-PDR: p = 0.014; ICG-R15: p = 0.014). The sensitivity for detection of an initial stage of liver fibrosis compared to no liver fibrosis (Ishak  ≥  1) was 0.40; the corresponding specificity was 0.80. The differentiation of advanced liver fibrosis or cirrhosis (Ishak ≥ 4) compared to other stages of liver fibrosis was 0.75, with a specificity of 0.81. (4) Conclusions: This study shows that the ICG test, as a non-invasive diagnostic test, is able to differentiate patients with no liver fibrosis from patients with advanced liver fibrosis and liver cirrhosis. The ICG test seems to be helpful in monitoring patients with liver fibrosis regarding compensation levels, thus potentially enabling physicians to both detect progression from compensated liver fibrosis to advanced liver fibrosis and cirrhosis and to initiate antifibrotic treatment at an earlier stage.

A Simple and Sensitive LC-MS/MS for Quantitation of ICG in Rat Plasma: Application to a Pre-Clinical Pharmacokinetic Study

A selective, sensitive, and rapid liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed and validated for the quantitation of ICG in rat plasma. The chromatographic separation was achieved using an ACE excel C18 (3 µm, 50 × 3.0 mm) column, with a mobile phase composition of 0.1% formic acid and 0.1% formic acid in acetonitrile, using a gradient flow at a rate of 0.3 mL/min. The MS was operated at a unit resolution in the multiple reaction monitoring mode, using the precursor ion → product ion combinations of 753.3 → 330.2 m/z (ICG) and 747.45 → 717.50 (Cy7.5 amine) with a run time of 5 min. The assay was linear over a concentration range of 1–1000 ng/mL with a regression coefficient (r2) of 0.998 or better. The inter and intra-batch precision (% relative standard deviation, %RSD) was lower than 13.5%, with accuracy (%Bias) between −10.03% and 11.56%. The ICG was stable under laboratory storage and handling conditions. The validated method was successfully applied to preclinical pharmacokinetic (PK) studies of ICG at a dose of 0.39 mg/kg in rats. PK parameters suggested the highest plasma concentration within 2 min of intravenous dosing with restricted systemic distribution and rapid clearance.

Hepatoprotective potential of a novel quinazoline derivative in thioacetamide-induced liver toxicity

Purpose: The compound quinazoline Q-Br, 3-(5-bromo-2-hydroxybenzylideneamino)-2-(5-bromo-2 hydroxyphenyl) 2,3-dihydroquinazoline-4(1H)-one (Q-Br) was evaluated for its antioxidant capacity and potential hepatoprotectivity against sub-chronic liver toxicity induced by thioacetamide in rats.

Materials and Methods: Rats were assigned into five groups; healthy (normal) and cirrhosis control groups were given 5% Tween 20 orally, the reference control group was given a Silymarin dose of 50 mg/kg, and low-dose Q-Br and high-dose Q-Br groups were given a daily dose of 25 mg/kg and 50 mg/g Q-Br, respectively. Liver status was detected via fluorescence imaging with intravenous injection of indocyanine green (ICG) and a plasma ICG clearance test. Liver malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were also tested. The degree of fibrosis was determined histologically by hematoxylin and eosin and Masson’s Trichrome staining. The immunohistochemistry of liver tissue inhibitor of metalloproteinase (TIMP-1), matrix metalloproteinase (MMP-2), and alpha-smooth muscle actin (α-SMA) was performed.

Results: Q-Br recorded mild antioxidant capacity, dose-dependent improvement in the liver status, and inhibition of oxidative stress compared to cirrhosis control. Histopathology notified a remarkable reduction in the degree of fibrosis. Immunohistochemistry revealed an obvious low expression of MMP-2 and α-SMA along with a higher expression of TIMP-1 in Q-Br- and Silymarin-treated livers.

Conclusion: Q-Br treatment altered the course of toxicity induced by thioacetamide suggesting significant hepatoprotective potential of Q-Br treatment.

Association between effective hepatic blood flow and the severity and prognosis of hepatitis B virus-related acute on chronic liver failure

BACKGROUND

Hepatic inflammation resulted in hepatocyte necrosis and microcirculatory dysfunction in acute on chronic liver failure (ACLF) with cirrhosis or not. The influence of effective hepatic blood flow (EHBF) on the severity of liver failure has not been fully elucidated.

AIM

The aim of this study was to assess the correlation between the EHBF and the severity and the prediction of 90-day mortality rate of hepatitis B virus-related ACLF (HBV-ACLF).

METHODS

In this retrospective study, patients hospitalized for HBV-ACLF or decompensated cirrhosis and who underwent an indocyanine green (ICG) clearance test between June 2016 and July 2018 were enrolled. EHBF was measured by the ICG clearance test and patients were categorized into the ACLF without cirrhosis (HBV-ACLF-no-Cir), ACLF with cirrhosis (HBV-ACLF-Cir) and decompensated cirrhosis (HBV-De-Cir).

RESULTS

A total of 522 patients (HBV-ACLF-no-Cir: 84, HBV-ACLF-Cir: 111 and HBV-De-Cir: 327) were enrolled. The mean EHBF in the HBV-De-Cir was significantly higher than that in the HBV-ACLF-no-Cir and HBV-ACLF-Cir (0.36 vs. 0.21 vs. 0.20 L/min, P < 0.001). EHBF was significantly correlated with the total bilirubin, prothrombin activity and model for end-stage liver disease (MELD) in the HBV-ACLF-no-Cir. The predicted 90-day mortality rate using the MELD, EHBF, ICG-retention rate at 15 min (R15%) and EHBF-R15% scores were similar. The sensitivity and specificity of the EHBF varied between 68.5-80.2% and 45.8-73.7%, respectively. The EHBF-MELD score had the highest specificity.

CONCLUSION

EHBF was significantly lower in the patients with ACLF compared to decompensated cirrhosis. The EHBF were closely related to the severity of HBV-ACLF and can be used for predicting the 90-day mortality rate of HBV-ACLF.

Value of contrast-enhanced ultrasound for preoperative assessment of liver reserve function in patients with liver tumors

This study aimed to investigate the value of contrast-enhanced ultrasound (CEUS) for preoperative assessment of liver reserve function in patients with liver tumors. The indocyanine green (ICG) clearance tests and CEUS examinations of 45 noncirrhotic patients with liver tumors were performed prior to liver resection. Parameters time to peak (TtoPk), arrival time (Atm) as well as perfusion parameters A, k and A x k were generated from time-intensity curve (TIC) of CEUS. The correlation analyses of the ICG clearance per unit time (ICGK) and the retention rate at 15 min (ICGR15) with TtoPk, Atm, A, k and A x k were performed, and the diagnostic ability as well as optimal cut-off values of TtoPk and Atm for differentiating patients with ICGR15>10% from ICGR15<10% were analyzed. There were significant correlations of ICGK with TtoPk and Atm, and the correlation coefficients were 0.363 (p = 0.014) and -0.482 (p = 0.001), respectively. Significant correlations of ICGR15 with TtoPk and Atm were revealed, and the correlation coefficients were -0.416 (p = 0.004) and 0.303 (p = 0.043), respectively. No correlation of ICGK or ICGR15 with A, k and A x k was found in this study. There were significant differences in TtoPk and Atm between patients with ICGR15>10% and ICGR15<10% (p = 0.028 and p = 0.026, respectively). TtoPk and Atm both had good diagnostic abilities in diagnosing patients with ICGR15>10% verusus ICGR15<10% (AUROC = 0.711 and 0.721, respectively). For ICGR15>10% vs ICGR15, the optimal cut-off values of TtoPk and Atm were 13.307 s and 11.007 s, respectively, while the sensitivity and specificity were 75.0% and 72.7%, 60.6% and 75.0%, respectively. This study revealed that CEUS has the potential to be a new method to evaluate the liver reserve function of patients. With the optimal cut-off values of TtoPk and Atm, qualitative assessment of patients with ICGR15>10% could be more easily achieved by CEUS with good diagnostic abilities.

Diagnostic performance of Gd-EOB-DTPA-enhanced MRI for evaluation of liver dysfunction: a multivariable analysis of 3T MRI sequences

OBJECTIVE

The aim of this study was to evaluate the diagnostic performance of a multiparametric gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced MRI examination for the estimation of liver dysfunction classified by the Model for End-Stage Liver Disease (MELD) score.

RESULTS

Liver dysfunction can be assessed by different methods. In a logistic regression analysis, T1- and T2-weighted images were affected by impaired liver function. In the assessment of liver dysfunction, the reduction rate in T1 mapping sequences showed a significant correlation in simple and multiple logistic regression.

CONCLUSION

Changes in Gd-EOB-DTPA-enhanced MRI between plain images and images obtained during the hepatobiliary phase allowed good prediction of liver dysfunction, especially when using T1 mapping sequences.

MATERIALS AND METHODS

A total of 199 patients underwent contrast-enhanced MRI with a hepatocyte-specific contrast agent at 3T. In the multivariable analysis, the full range of available MRI sequences was used to estimate the liver dysfunction of patients with various MELD scores.

Liver function assessment by indocyanine green plasma disappearance rate in patients with intra-abdominal hypertension after "non-hepatic" abdominal surgery

BACKGROUND AND OBJECTIVE

Liver function assessment in patients with intra-abdominal hypertension (IAH) after major abdominal surgery is complex and often confounding. Elevated intra-abdominal pressure (IAP) often occurs after major abdominal surgery, and is associated with decreased abdominal blood flow and organ dysfunction, and it could cause abdominal compartment syndrome (ACS), which is a life-threatening condition. Plasma disappearance rate (PDR) of indocyanine green (ICG) and ICG retention rate after 15 min (R15) were used to evaluate liver function and as a prognostic parameter after major abdominal surgery.

METHODS

In this prospective/observational study, 51 patients were followed in the surgical intensive care unit after major abdominal surgery (operation of the small and large intestine, stomach, pancreas, spleen, or resection of the abdominal aorta), 29 had IAH. The PDR-ICG and R15 were analyzed 24 h after surgery concurrently with IAP, APP, bilirubin, AST, ALT, prothrombin time, albumin, cardiac index, arterial lactate, oxygen delivery, MAP (mean arterial pressure), APACHE II (acute physiology and chronic health evaluation), SOFA (sequential organ failure assessment), and SAPS II (simplified acute physiology score). IAH has been defined as a peak intra-abdominal pressure (IAP) value of ≥12 mmHg, at a minimum, as two standardized measurements obtained 1-6 h apart.

RESULTS

The PDR-ICG measured 24 h after surgery was not different among groups (20.95% [SD = 10.34] vs 25.40% [SD = 7.42]), p = .094. ICG R15 was significantly higher in patients with IAH, 11.10% [SD = 13.82] vs 8.30 [SD = 11.46], p < .05, respectively. The PDR/ICG value was significantly lower in non-survivors than survivors (16.82 [SD = 10.87] vs 24.35 [SD = 8.48], p < .05).

CONCLUSIONS

The results suggest that PDR/ICG and ICG R15 are useful dynamic tests for evaluation of complex liver function and survival prediction after major abdominal surgery in patients with IAH.

Indocyanine green clearance test to evaluate liver function in rat model of extrahepatic biliary atresia

BACKGROUND

Indocyanine green clearance test (ICG-K) has been shown as a sensitive marker of liver function in patients with cirrhosis. However, its role in the assessment of liver function in children with biliary atresia is not well established. The present study was undertaken to evaluate the ICG-K in an experimental model of cholangitis and partial biliary obstruction.

MATERIALS AND METHODS

Thirty albino rats were divided into 3 groups of 10 each. After exploration under anesthesia, a vial of OK-432 diluted in 0.2 ml of normal saline was injected into the common bile duct (CBD) in rats of Groups B and C. In the control Group A, only saline was injected. Re-exploration was done at 3 weeks in Groups A and B and at 6 weeks in Group C, and freshly prepared ICG was injected into the inferior vena cava. Blood samples were collected at periodic intervals, optical density of the serum was measured, and half-life of ICG and fractional clearance (K) were calculated. Blood and tissue samples were obtained for biochemical tests and histological examination.

RESULTS

The histological changes in CBD and liver were maximum in Group B; this correlated well with the K-value in this group, which was significantly delayed. In Group C, clearance was delayed than the control group with histological changes ranged from mild to moderate inflammation. The control group had normal histology of liver and CBD, and only four rats showed mild portal inflammation.

CONCLUSION

ICG clearance rate is a reliable marker of liver function and can be utilized for evaluation of liver function in postoperative extrahepatic biliary atresia patients.

MRI-based estimation of liver function by intravoxel incoherent motion diffusion-weighted imaging

PURPOSE

To explore the usefulness of intravoxel incoherent motion (IVIM) to evaluate the hepatic functional reserve as expressed by the model for Child-Pugh class.

MATERIALS AND METHODS

IVIM diffusion-weighted imaging (DWI) using 10 different b values were performed on a Philips 3.0T MR scanner in 70 patients with liver cirrhosis and 60 healthy volunteers as the control group. Patients with liver cirrhosis were subdivided into three groups: Child-Pugh class A: 29 cases; Child-Pugh class B: 19 cases; Child-Pugh class C: 22 cases. Pure molecular diffusion (D), pseudo-diffusion (D*), perfusion fraction (f) and apparent diffusion coefficient (ADC) values were calculated, and used to determine liver function, as indicated by the Child-Pugh class.

RESULTS

The ICC values of D, D*, f and ADC between two radiologists were 0.997, 0.986, 0.985 and 0.995, respectively. D*, f and ADC values of liver cirrhosis group were significantly lower than control group (P<0.001, P=0.016, P=0.042, respectively). D*, f and ADC values significantly decreased with increasing Child-Pugh scores (p<0.05). Child-Pugh scores were inversely correlated with D* and f values (r=-0.423, r=-0.620, respectively). The areas under the curve (AUCs) of D* and f for evaluating liver function were 0.67-0.90 and 0.78-0.89, respectively.

CONCLUSION

IVIM DWI may be a useful image-based method for assessing liver function.

Liver surgery in cirrhosis and portal hypertension

The prevalence of hepatic cirrhosis in Europe and the United States, currently 250 patients per 100000 inhabitants, is steadily increasing. Thus, we observe a significant increase in patients with cirrhosis and portal hypertension needing liver resections for primary or metastatic lesions. However, extended liver resections in patients with underlying hepatic cirrhosis and portal hypertension still represent a medical challenge in regard to perioperative morbidity, surgical management and postoperative outcome. The Barcelona Clinic Liver Cancer classification recommends to restrict curative liver resections for hepatocellular carcinoma in cirrhotic patients to early tumor stages in patients with Child A cirrhosis not showing portal hypertension. However, during the last two decades, relevant improvements in preoperative diagnostic, perioperative hepatologic and intensive care management as well as in surgical techniques during hepatic resections have rendered even extended liver resections in higher-degree cirrhotic patients with portal hypertension possible. However, there are few standard indications for hepatic resections in cirrhotic patients and risk stratifications have to be performed in an interdisciplinary setting for each individual patient. We here review the indications, the preoperative risk-stratifications, the morbidity and the mortality of extended resections for primary and metastatic lesions in cirrhotic livers. Furthermore, we provide a review of literature on perioperative management in cirrhotic patients needing extrahepatic abdominal surgery and an overview of surgical options in the treatment of hepatic cirrhosis.

Liver reserve function assessment by acoustic radiation force impulse imaging

AIM: To evaluate the utility of liver reserve function by acoustic radiation force impulse (ARFI) imaging in patients with liver tumors.

METHODS: Seventy-six patients with liver tumors were enrolled in this study. Serum biochemical indexes, such as aminotransferase (ALT), aspartate aminotransferase (AST), serum albumin (ALB), total bilirubin (T-Bil), and other indicators were observed. Liver stiffness (LS) was measured by ARFI imaging, measurements were repeated 10 times, and the average value of the results was taken as the final LS value. Indocyanine green (ICG) retention was performed, and ICG-K and ICG-R15 were recorded. Child-Pugh (CP) scores were carried out based on patient’s preoperative biochemical tests and physical condition. Correlations among CP scores, ICG-R15, ICG-K and LS values were observed and analyzed using either the Pearson correlation coefficient or the Spearman rank correlation coefficient. Kruskal-Wallis test was used to compare LS values of CP scores, and the receiver-operator characteristic (ROC) curve was used to analyze liver reserve function assessment accuracy.

RESULTS: LS in the ICG-R15 10%-20% group was significantly higher than in the ICG-R15 < 10% group; and the difference was statistically significant (2.19 ± 0.27 vs 1.59 ± 0.32, P < 0.01). LS in the ICG-R15 > 20% group was significantly higher than in the ICG-R15 < 10% group; and the difference was statistically significant (2.92 ± 0.29 vs 1.59 ± 0.32, P < 0.01). The LS value in patients with CP class A was lower than in patients with CP class B (1.57 ± 0.34 vs 1.86 ± 0.27, P < 0.05), while the LS value in patients with CP class B was lower than in patients with CP class C (1.86 ± 0.27 vs 2.47 ± 0.33, P < 0.01). LS was positively correlated with ICG-R15 (r = 0.617, P < 0.01) and CP score (r = 0.772, P < 0.01). Meanwhile, LS was negatively correlated with ICG-K (r = -0.673, P < 0.01). AST, ALT and T-Bil were positively correlated with LS, while ALB was negatively correlated with LS (P < 0.05). The ROC curve revealed that the when the LS value was 2.34 m/s, the Youden index was at its highest point, sensitivity was 69.2% and specificity was 92.1%.

CONCLUSION: For patients with liver tumors, ARFI imaging is a useful tool for assessing liver reserve function.

Clinical implication of the preoperative GSA index in ⁹⁹mTc-GSA scintigraphy in hepatitis C virus-related hepatocellular carcinoma

We aimed to examine the relationship between the preoperative GSA index [uptake ratio of the liver to the liver plus heart at 15 min (LHL15) to uptake ratio of the heart at 15 min to that at 3 min (HH15) ratio] calculated from 99mTc‑labeled diethylene triamine pentaacetate-galactosyl human serum albumin (99mTc-GSA) scintigraphy and background liver fibrosis and to investigate whether the GSA index can be a useful predictor in hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) patients treated with surgical resection (SR). A total of 213 HCV-related HCC patients were analyzed. Receiver operating characteristic (ROC) curve analysis was performed for calculating the area under the ROC (AUROC) for nine noninvasive parameters including GSA index, indocyanine green retention at 15 min, aspartate aminotransferase (AST) to platelet ratio index, FIB-4 index, AST to alanine aminotransferase ratio, serum albumin, total bilirubin, platelet count and prothrombin time for cirrhosis. We also examined predictive factors associated with overall survival (OS) and recurrence-free survival (RFS) after SR in univariate and multivariate analyses. There were 153 males and 60 females with the mean age of 69.9 years. The median observation periods were 2.8 years. The mean maximum tumor size was 4.1 cm. HH15 ranged from 0.452 to 0.897. LHL15 ranged from 0.669 to 0.982. The mean value of the GSA index was 1.41. Among the nine parameters, the GSA index yielded the highest AUROC for cirrhosis with a level of 0.786 at an optimal cut-off value of 1.37 (sensitivity, 65.9%; specificity, 79.0%). In multivariate analyses, the GSA index was an independent predictor (P<0.001) linked to RFS and it had a marginal significance in terms of OS (P=0.074). In conclusion, the preoperative GSA index can be a useful predictor in HCV-related HCC patients treated with SR.

Role of the 13C-methacetin breath test in the assessment of acute liver injury in a rat model

AIM: To evaluate the role of the ¹³C-methacetin breath test (¹³C-MBT) in the assessment of acute liver injury in a rat model.

METHODS: Acute liver injury in rats was induced by a single intraperitoneal injection of D-galactosamine (D-GalN). Forty-eight male Sprague-Dawley rats were randomly assigned to a control group (n = 8) and five model groups (each n = 8), and acute liver injury was assessed at different time points (6, 12, 24, 48 and 72 h) after D-GalN injection. The ¹³C-MBT, biochemical tests, 15-min retention rate of indocyanine green (ICG_R15), and liver biopsy were performed and compared between the control and model groups. Correlations between parameters of the ¹³C-MBT (T_max, MV_max, CUM₁₂₀ and DOB_max), biochemical tests, ICG_R15 and liver necrosis score were also analyzed using Spearman’s correlation analysis.

RESULTS: T_max, MV_max, CUM₁₂₀ and DOB_max, as well as most of the traditional methods, correlated with the liver necrosis score (r = 0.493, P < 0.05; r = -0.731, P < 0.01; r = -0.618, P < 0.01; r = -0.592, P < 0.01, respectively). MV_max, CUM₁₂₀ and DOB_max rapidly decreased and were lower than those in the controls as early as 6 h after D-GalN injection (3.84 ± 0.84 vs 5.06 ± 0.78, P < 0.01; 3.35 ± 0.72 vs 4.21 ± 1.44, P < 0.05; 52.3 ± 20.58 vs 75.1 ± 9.57, P < 0.05, respectively) and reached the lowest point 24 h after D-GalN injection. MV_max, CUM₁₂₀ and DOB_max returned to normal levels 72 h after D-GalN injection and preceded most of the traditional methods, including liver biopsy.

CONCLUSION: The ¹³C-MBT is a sensitive tool for the timely detection of acute liver injury and early prediction of recovery in a rat model. Further clinical studies are warranted to validate its role in patients with acute liver injury.

Green light for liver function monitoring using indocyanine green? An overview of current clinical applications

The dye indocyanine green is familiar to anaesthetists, and has been studied for more than half a century for cardiovascular and hepatic function monitoring. It is still, however, not yet in routine clinical use in anaesthesia and critical care, at least in Europe. This review is intended to provide a critical analysis of the available evidence concerning the indications for clinical measurement of indocyanine green elimination as a diagnostic and prognostic tool in two areas: its role in peri-operative liver function monitoring during major hepatic resection and liver transplantation; and its role in critically ill patients on the intensive care unit, where it is used for prediction of mortality, and for assessment of the severity of acute liver failure or that of intra-abdominal hypertension. Although numerous studies have demonstrated that indocyanine green elimination measurements in these patient populations can provide diagnostic or prognostic information to the clinician, 'hard' evidence - i.e. high-quality prospective randomised controlled trials - is lacking, and therefore it is not yet time to give a green light for use of indocyanine green in routine clinical practice.

Assessing liver function by liver enhancement during the hepatobiliary phase with Gd-EOB-DTPA-enhanced MRI at 3 Tesla

OBJECTIVES

The purpose of this study was to evaluate the usefulness of Gd-EOB-DTPA-enhanced 3-T MRI to determine the hepatic functional reserve expressed by the model for end-stage liver disease (MELD) score.

METHODS

A total of 121 patients with normal liver function (NLF; MELD score ≤ 10) and 29 patients with impaired liver function (ILF; MELD score > 10) underwent contrast-enhanced MRI with a hepatocyte-specific contrast agent at 3T. T1-weighted volume interpolated breath-hold examination (VIBE) sequences with fat suppression were acquired before and 20 min after contrast injection. Relative enhancement (RE) between plain signal intensity and contrast-enhanced signal intensity was calculated and was used to determine Gd-EOB-DTPA uptake into the liver parenchyma for patients with different MELD scores.

RESULTS

RE differed significantly (p ≤ 0.001) between patients with NLF (87.2 ± 29.5 %) and patients with ILF (45.4 ± 26.5 %). The optimal cut-off value for RE to differentiate NLF from ILF was 47.7 % (AUC 0.87). This cut-off value showed a sensitivity of 82.8 % and a specificity of 92.7 % for the differentiation of the analysed groups.

CONCLUSION

Gd-EOB-DTPA uptake in hepatocytes is strongly affected by liver function. Gd-EOB-DTPA-enhanced MRI and assessment of RE during the hepatobiliary phase (HBP) may serve as a useful image-based test in liver imaging for determining regional and global liver function.

KEY POINTS

Hepatic uptake of Gd-EOB-DTPA is strongly affected by liver function. Relative enhancement during HBP in GD-EOB-DTPA MRI correlates with the MELD score. Assessment of relative enhancement may help improve treatment in routine clinical practice.