Endovascular Assessment of Liver Hemodynamics in Patients with Cirrhosis Complicated by Portal Hypertension.

The hepatic venous pressure gradient (HVPG) is currently considered the gold standard to assess portal hypertension (PH) in patients with cirrhosis. A meticulous technique is important to achieve accurate and reproducible results, and values obtained during measurement are applied in risk stratification of patients with PH, allocating treatment options, monitoring follow-up, and deciding management options in surgical patients. The use of portosystemic pressure gradients in patients undergoing placement of transjugular intrahepatic portosystemic shunts has been studied extensively and has great influence on decisions on shunt diameter. The purpose of this study was to describe the recommended technique to measure HVPG and portosystemic pressure gradient and to review the existing literature describing the importance of these hemodynamic measurements in clinical practice.

Assessment of portal hypertension severity using machine learning models in patients with compensated cirrhosis.

BACKGROUND & AIMS: In individuals with compensated advanced chronic liver disease (cACLD), the severity of portal hypertension (PH) determines the risk of decompensation. Invasive measurement of the hepatic venous pressure gradient (HVPG) is the diagnostic gold standard for PH. We evaluated the utility of machine learning models (MLMs) based on standard laboratory parameters to predict the severity of PH in individuals with cACLD. METHODS: A detailed laboratory workup of individuals with cACLD recruited from the Vienna cohort (NCT03267615) was utilised to predict clinically significant portal hypertension (CSPH, i.e., HVPG ≥10 mmHg) and severe PH (i.e., HVPG ≥16 mmHg). The MLMs were then evaluated in individual external datasets and optimised in the merged cohort. RESULTS: Among 1,232 participants with cACLD, the prevalence of CSPH/severe PH was similar in the Vienna (n = 163, 67.4%/35.0%) and validation (n = 1,069, 70.3%/34.7%) cohorts. The MLMs were based on 3 (3P: platelet count, bilirubin, international normalised ratio) or 5 (5P: +cholinesterase, +gamma-glutamyl transferase, +activated partial thromboplastin time replacing international normalised ratio) laboratory parameters. The MLMs performed robustly in the Vienna cohort. 5P-MLM had the best AUCs for CSPH (0.813) and severe PH (0.887) and compared favourably to liver stiffness measurement (AUC: 0.808). Their performance in external validation datasets was heterogeneous (AUCs: 0.589-0.887). Training on the merged cohort optimised model performance for CSPH (AUCs for 3P and 5P: 0.775 and 0.789, respectively) and severe PH (0.737 and 0.828, respectively). CONCLUSIONS: Internally trained MLMs reliably predicted PH severity in the Vienna cACLD cohort but exhibited heterogeneous results on external validation. The proposed 3P/5P online tool can reliably identify individuals with CSPH or severe PH, who are thus at risk of hepatic decompensation. IMPACT AND IMPLICATIONS: We used machine learning models based on widely available laboratory parameters to develop a non-invasive model to predict the severity of portal hypertension in individuals with compensated cirrhosis, who currently require invasive measurement of hepatic venous pressure gradient. We validated our findings in a large multicentre cohort of individuals with advanced chronic liver disease (cACLD) of any cause. Finally, we provide a readily available online calculator, based on 3 (platelet count, bilirubin, international normalised ratio) or 5 (platelet count, bilirubin, activated partial thromboplastin time, gamma-glutamyltransferase, choline-esterase) widely available laboratory parameters, that clinicians can use to predict the likelihood of their patients with cACLD having clinically significant or severe portal hypertension.

Assessment of clinically significant portal hypertension by two-dimensional shear wave elastography.

BACKGROUND AND AIMS: To evaluate two-dimensional shear wave elastography (2DSWE) in parallel with transient elastography (TE) for diagnosing clinically significant portal hypertension (CSPH) and high-risk varices (HRV) in patients with chronic liver disease. PATIENTS AND METHODS: Consecutive patients with suspicion of compensated advanced chronic liver disease (cACLD) [liver stiffness measurement (LSM) ≥ 10 kPa by TE, or morphological signs suggestive of cACLD on imaging], with no history of liver decompensation, underwent hepatic venous pressure gradient (HVPG) measurement, transjugular liver biopsy and esophagogastroduodenoscopy, which served as the reference methods for diagnosing CSPH, cACLD and HRV. All patients underwent LSM and spleen stiffness measurements (SSM) by 2DSWE and TE. RESULTS: Seventy-six (76) patients were included (78% men, mean age 62 years, body mass index 28.3 kg/m2 , 36.8% alcoholic, 30.3% non-alcoholic fatty liver disease, 14.5% viral hepatitis). Of them, 80.3%, 69.7%, 52.6% and 22.4% had cACLD, cirrhosis, CSPH and HRV respectively. LSM performed better than SSM in diagnosing CSPH and HRV. For CSPH, AUROCs (0.926 vs. 0.866), optimal cut-offs (20.1 vs. 20.2 kPa) and sensitivity/specificity (80.5%/94.3% vs. 77.5% /86.1%) were comparable for 2DSWE and TE. Ruling-out of CSPH by 2DSWE (LSM at cut-off with ≥90% sensitivity (13.5 kPa) and platelets ≥ 150 x 109 /L) performed comparably to TE, with 1/24 cases falsely classified as negative. For HRV, AUROCs were similar (0.875 2DSWE, 0.851 TE) with similar optimal LSM cut-offs enabling 100% sensitivity and ruling-out HRV. CONCLUSION: Liver stiffness measurement by 2DSWE appears to perform equally well as TE for diagnosing CSPH and ruling-out HRV in compensated chronic liver disease.

Magnetic resonance parametric mapping of the spleen for non-invasive assessment of portal hypertension.

OBJECTIVES: In patients with advanced liver disease, portal hypertension is an important risk factor, leading to complications such as esophageal variceal bleeding, ascites, and hepatic encephalopathy. This study aimed to determine the diagnostic value of T1 and T2 mapping and extracellular volume fraction (ECV) for the non-invasive assessment of portal hypertension. METHODS: In this prospective study, 50 participants (33 patients with indication for trans-jugular intrahepatic portosystemic shunt (TIPS) and 17 healthy volunteers) underwent MRI. The derivation and validation cohorts included 40 and 10 participants, respectively. T1 and T2 relaxation times and ECV of the liver and the spleen were assessed using quantitative mapping techniques. Direct hepatic venous pressure gradient (HVPG) and portal pressure measurements were performed during TIPS procedure. ROC analysis was performed to compare diagnostic performance. RESULTS: Splenic ECV correlated with portal pressure (r = 0.72; p < 0.001) and direct HVPG (r = 0.50; p = 0.003). No significant correlations were found between native splenic T1 and T2 relaxation times with portal pressure measurements (p > 0.05, respectively). In the derivation cohort, splenic ECV revealed a perfect diagnostic performance with an AUC of 1.000 for the identification of clinically significant portal hypertension (direct HVPG ≥ 10 mmHg) and outperformed other parameters: hepatic T2 (AUC, 0.731), splenic T2 (AUC, 0.736), and splenic native T1 (AUC, 0.806) (p < 0.05, respectively). The diagnostic performance of mapping parameters was comparable in the validation cohort. CONCLUSION: Splenic ECV was associated with portal pressure measurements in patients with advanced liver disease. Future studies should explore the diagnostic value of parametric mapping accross a broader range of pressure values. KEY POINTS: • Non-invasive assessment and monitoring of portal hypertension is an area of unmet interest. • Splenic extracellular volume fraction is strongly associated with portal pressure in patients with end-stage liver disease. • Quantitative splenic and hepatic MRI-derived parameters have a potential to become a new non-invasive diagnostic parameter to assess and monitor portal pressure.

Quantitative assessment of portal hypertension with bi-parametric dual-frequency hepatic MR elastography in mouse models.

OBJECTIVES: To determine the potential of bi-parametric dual-frequency hepatic MR elastography (MRE) for predicting portal pressure (PP) in mouse models of portal hypertension (PHTN) with the presence of varying hepatic fibrosis. METHODS: We studied 73 wild-type male mice, including 22 mice with hepatic congestion, 20 mice with cholestatic liver injury, and 31 age-matched sham mice. Hepatic shear stiffness (SS) and volumetric strain (VS) were calculated by 3D MRE acquired at 80 and 200 Hz. We measured PP immediately after MRE. Liver fibrosis was verified by hydroxyproline assay. We predicted PP by fitting generalized linear models with single- and dual-frequency SS and VS, respectively. The relationship between predicted and actual PP was evaluated by Spearman's correlation. We compared the prediction accuracy of portal hypertension for all models with DeLong tests at a significance level of 0.05. RESULTS: Animals with congestive or cholestatic liver disease developed significant PHTN and hepatic fibrosis to varying degrees. In both models, SS increased, while VS decreased significantly compared with shams. All bi-parametric models had high diagnostic accuracy for PHTN. The dual-frequency models (AUCs: 0.90 [81-95%], 0.91 [81-95%]) had substantially or significantly higher accuracy than single-frequency ones (AUCs: 0.83 [71-91%], and 0.78 [66-87%]). The predicted PP of dual-frequency models also showed stronger correlations with actual PP than single-frequency predictions. CONCLUSIONS: The bi-parametric dual-frequency model improved the diagnostic accuracy of liver MRE in diagnosing PHTN in preclinical models. This technical advance has the potential to monitor PHTN progression and treatment efficacy in the presence of varying fibrosis. KEY POINTS: • Bi-parametric hepatic MR elastography can predict portal pressure. • The prediction models of shear stiffness and volumetric strain with dual-frequency measurements demonstrate high diagnostic accuracy (AUCs > 0.9) in two different portal hypertension mouse models with varying fibrosis.

Pre-surgical risk assessment in patients with cirrhosis.

Over the last decades, significant improvements in the clini- cal management of patients with cirrhosis have increased their life expectancy. Thus, indications for surgical procedures other than liver transplantation are becoming more frequent. However, patients with advanced liver disease are at high risk of perioperative morbidity and mortality. This is the consequence of multiple factors that include the presence of portal hypertension, alterations on hemostasis and coagulation, the immune dysfunction that entails an increased risk of infections, and the impaired synthesis of proteins that impacts on the nutritional status and the wound healing. Surgical outcomes are not only determined by the severity of the liver disease, but also by the type of surgery and the presence of other comorbidities. Different models to predict mortality have been proposed, including the MELD score, the Child-Pugh classification, the hepatic venous pressure gradient, and the Mayo postoperative mortality risk calculator, among others. Multidisciplinary committees including surgeons, anesthesiologists, hepatologists, critical care physicians and other specialties involved in each case, should assess individually the risk-benefit of the surgical procedure, also considering patient`s expectations and will.

Assessment of a biofluid mechanics-based model for calculating portal pressure in canines.

BACKGROUND: Portal hypertension is a severe complication caused by various chronic liver diseases. The standard methods for detecting portal hypertension (hepatic venous pressure gradient and free portal pressure) are available in only a few hospitals due to their technical difficulty and invasiveness; thus, non-invasive measuring methods are needed. This study aimed to establish and assess a novel model to calculate free portal pressure based on biofluid mechanics. RESULT: Comparison of each dog's virtual and actual free portal pressure showed that a biofluid mechanics-based model could accurately predict free portal pressure (mean difference: -0.220, 95% CI: - 0.738 to 0.298; upper limit of agreement: 2.24, 95% CI: 1.34 to 3.14; lower limit of agreement: -2.68, 95% CI: - 3.58 to - 1.78; intraclass correlation coefficient: 0.98, 95% CI: 0.96 to 0.99; concordance correlation coefficient: 0.97, 95% CI: 0.93 to 0.99) and had a high AUC (0.984, 95% CI: 0.834 to 1.000), sensitivity (92.3, 95% CI: 64.0 to 99.8), specificity (91.7, 95% CI: 61.5 to 99.8), positive likelihood ratio (11.1, 95% CI: 1.7 to 72.8), and low negative likelihood ratio (0.08, 95% CI: 0.01 to 0.6) for detecting portal hypertension. CONCLUSIONS: Our study suggests that the biofluid mechanics-based model was able to accurately predict free portal pressure and detect portal hypertension in canines. With further research and validation, this model might be applicable for calculating human portal pressure, detecting portal hypertensive patients, and evaluating disease progression and treatment efficacy.

Non-invasive assessment of portal hypertension by multi-parametric magnetic resonance imaging of the spleen: A proof of concept study.

BACKGROUND AND AIMS: Non-invasive assessment of portal hypertension is an area of unmet need. This proof of concept study aimed to evaluate the diagnostic accuracy of a multi-parametric magnetic resonance technique in the assessment of portal hypertension. Comparison to other non-invasive technologies was a secondary aim. METHODS: T1 and T2* maps through the liver and spleen were acquired prior to trans-jugular liver biopsy and hepatic vein pressure gradient (HVPG) measurement. T1 measurements reflect changes in tissue water content, but this relationship is confounded by the presence of iron, which in turn can be quantified accurately from T2* maps. Data were analysed using LiverMultiScan (Perspectum Diagnostics, Oxford, UK) which applies an algorithm to remove the confounding effect of iron, yielding the "iron corrected T1" (cT1). Sensitivity, specificity, diagnostic values and area under the curve were derived for spleen cT1, liver cT1, transient elastography, and serum fibrosis scores. HVPG was the reference standard. RESULTS: Nineteen patients (15 men) with median age 57 years were included. Liver disease aetiologies included non-alcoholic fatty liver disease (n = 9; 47%) and viral hepatitis (n = 4; 21%). There was strong correlation between spleen cT1 and HVPG (r = 0.69; p = 0.001). Other non-invasive biomarkers did not correlate with HVPG. Spleen cT1 had excellent diagnostic accuracy for portal hypertension (HVPG >5 mmHg) and clinically significant portal hypertension (HVPG ≥10 mmHg) with an area under the receiver operating characteristic curve of 0.92 for both. CONCLUSION: Spleen cT1 is a promising biomarker of portal pressure that outperforms other non-invasive scores and should be explored further.

Real-time shear wave elastography (SWE) assessment of short- and long-term treatment outcome in Budd-Chiari syndrome: A pilot study.

PURPOSE: The first aim of this study was to analyze the relationships between liver stiffness measurement, hepatic venous pressure and liver fibrosis. The second aim was to demonstrate the utility of real-time shear wave elastography for evaluation of Budd-Chiari syndrome patients before and after balloon hepatic venous angioplasty. MATERIALS AND METHODS: A total of 32 patients with Budd-Chiari syndrome slated for successful balloon angioplasty met the inclusion and exclusion criteria. Shear wave elastography was used to generate dynamic liver stiffness measurement 2 days before angioplasty and 2 days, 3 months, and 6 months after angioplasty. Hepatic venous pressures were measured during balloon angioplasty. Correlations among liver stiffness, hepatic venous pressure, and fibrosis were assessed. RESULT: Mean liver stiffness was 35.17 ± 10.60 kPa, 20.15 ± 5.47 kPa, 15.36 ± 4.34 kPa and 15.68 ± 5.58 kPa at baseline and 2 days, 3 months, and 6 months after angioplasty, respectively. Liver stiffness measured at 2 days and 3 months after angioplasty was significantly decreased (P < 0.001); liver stiffness measured at 6 months after angioplasty was not significantly different from that measured at 3 months after angioplasty (P = 0.636). Analysis of liver stiffness measurement and hepatic venous pressure before balloon angioplasty yielded a coefficient of correlation r = 0.701 (P < 0.001). Before and 2d after angioplasty, liver stiffness measurement did not correlated with fibrosis (r = - 0.170, P = 0.22), (r = 0.223, P = 0.220), respectively, while the LSM difference before and 2 days after angioplasty negatively correlated with stiffness severity (r = - 0.502, P = 0.003). Liver stiffness measured at 2 days and 3 months after angioplasty was significantly decreased (P < 0.001), remaining stable at 3 months, though still in the cirrhotic range. CONCLUSIONS: The liver stiffness of Budd-Chiari syndrome patients, measured by shear wave elastography, decreased considerably after hepatic venous recanalization, and significantly correlated with hepatic venous pressure though not with degree of fibrosis. Shear wave elastography may be effective in monitoring short- and long-term treatment outcomes in Budd-Chiari syndrome.

Invasive and non-invasive assessment of portal hypertension.

Portal hypertension is the central driver of complications in patients with chronic liver diseases and cirrhosis. The diagnosis of portal hypertension has important prognostic and clinical implications. In particular, screening for varices in patients with portal hypertension can effectively reduce the morbidity and mortality of variceal bleeding. In this article, we review the invasive and non-invasive methods to assess portal hypertension. Hepatic venous pressure gradient remains the gold standard to measure portal pressure but is invasive and seldom performed outside expert centers and research settings. In recent years, a number of non-invasive tests of fibrosis have shown good correlation with liver histology. They also show promise in identifying patients with portal hypertension and large varices. As a result, the latest Baveno VI consensus guidelines endorse the use of liver stiffness measurement by transient elastography and platelet count as initial assessment to select patients for varices screening. On the other hand, the performance of non-invasive tests in assessing the response to non-selective beta-blockers or transjugular intrahepatic portosystemic shunting is either suboptimal or unclear.

Elastography methods for the non-invasive assessment of portal hypertension.

INTRODUCTION: The gold standard to assess the presence and severity of portal hypertension remains the hepatic vein pressure gradient, however the recent development of non-invasive assessment using elastography techniques offers valuable alternatives. In this review, we discuss the diagnostic accuracy and utility of such techniques in patients with portal hypertension due to cirrhosis. Areas covered: A literature search focused on liver and spleen stiffness measurement with different elastographic techniques for the assessment of the presence and severity of portal hypertension and oesophageal varices in people with chronic liver disease. The combination of elastography with parameters such as platelet count and spleen size is also discussed. Expert commentary: Non-invasive assessment of liver fibrosis and portal hypertension is a validated tool for the diagnosis and follow-up of patients. Baveno VI recommended the combination of transient elastography and platelet count for ruling out varices needing treatment in patients with compensated advanced chronic liver disease. Assessment of aetiology specific cut-offs for ruling in and ruling out clinically significant portal hypertension is an unmet clinical need. The incorporation of spleen stiffness measurements in non-invasive algorithms using validated software and improved measuring scales might enhance the non-invasive diagnosis of portal hypertension in the next 5 years.

Acoustic Radiation Force Impulse (ARFI) Elastography and Serological Markers in Assessment of Liver Fibrosis and Free Portal Pressure in Patients with Hepatitis B.

BACKGROUND The aim of this study was to investigate the feasibility of using acoustic radiation force impulse (ARFI) elastography, AST-to-platelet ratio index (APRI), and FIB-4 in assessing liver fibrosis and free portal pressure in patients with hepatitis B. MATERIAL AND METHODS We enrolled 126 patients with hepatitis B who underwent liver surgery at the General Surgery Department of the First Affiliated Hospital of Shihezi University Medical School from February 2013 to August 2015. Preoperatively, shear wave velocity (SWV) of the liver was measured with the Siemens S2000 ultrasound system to reflect liver stiffness. Serological markers were collected and fibrosis indices APRI and FIB-4 were calculated. Intraoperatively, liver tissues were harvested and free portal pressure (FPP) was measured. Postoperatively, fibrosis of liver tissues was pathologically staged. RESULTS The results of SWV, APRI, FIB-4, and FPP were all correlated with the degree of liver fibrosis (Spearman correlation coefficients: r=0.777, P<0.001; r=0.526, P<0.001; r=0.471, P<0.001; p<0.000; r=0.675, p<0.000). Receiver operating characteristic curve (ROC) analysis showed that the areas under the curve (AUC) of ARFI, APRI, and FIB-4 in diagnosing liver fibrosis were 0.830, 0.768, and 0.717, respectively, for stage F≥1; 0.861, 0.773, and 0.754, respectively, for stage F≥2; 0.941, 0.793, and 0.779, respectively, for stage F≥3; and 0.945, 0.783, and 0.754, respectively, for stage F=4. SWV, APRI, and FIB-4 were all correlated with FPP (Pearson correlation coefficients: 0.387, P<0.001; 0.446, P<0.001; 0.419, P<0.001). CONCLUSIONS ARFI, APRI, and FIB-4 can assess liver fibrosis in patients with hepatitis B when assessing the portal venous pressure. The difference in diagnostic efficacy between the 3 was not significant.

Ultrasonography for Noninvasive Assessment of Portal Hypertension.

Portal hypertension is a major pathophysiology in patients with cirrhosis. Portal pressure is the gold standard to evaluate the severity of portal hypertension, and radiological intervention is the only procedure for pressure measurement. Ultrasound (US) is a simple and noninvasive imaging modality available worldwide. B-mode imaging allows broad applications for patients to detect and characterize chronic liver diseases and focal hepatic lesions. The Doppler technique offers real-time observation of blood flow with qualitative and quantitative assessments, and the application of microbubble-based contrast agents has improved the detectability of peripheral blood flow. In addition, elastography for the liver and spleen covers a wider field beyond the original purpose of fibrosis assessment. These developments enhance the practical use of US in the evaluation of portal hemodynamic abnormalities. This article reviews the recent progress of US in the assessment of portal hypertension.

Short article: Noninvasive assessment of portal hypertension and detection of esophageal varices in cirrhosis: state-of-the-art.

Portal hypertension (PHT) is a major consequence of any chronic liver disease and it is the main cause of complications in patients with cirrhosis. Measurement of hepatic vein pressure gradient is considered the gold standard for PHT assessment, together with its diagnosis and prognosis relevance. Even though hepatic vein pressure gradient measurement is a safe procedure, it is still considered an invasive technique and not widely available. There is thus a need for noninvasive methods that can predict the progression of PHT as well as the presence and the risk of complications related to esophageal varices. This review aimed to discuss the noninvasive markers used in the assessment of PHT and detection of high-risk esophageal varices in patients with liver cirrhosis. We focus on the main biomarkers, particularly those used in the routine assessment of chronic liver disease, and the physical methods that use tissue elastography as a diagnosis tool.

Clinical role of non-invasive assessment of portal hypertension.

Measurement of portal pressure is pivotal in the evaluation of patients with liver cirrhosis. The measurement of the hepatic venous pressure gradient represents the reference method by which portal pressure is estimated. However, it is an invasive procedure that requires significant hospital resources, including experienced staff, and is associated with considerable cost. Non-invasive methods that can be reliably used to estimate the presence and the degree of portal hypertension are urgently needed in clinical practice. Biochemical and morphological parameters have been proposed for this purpose, but have shown disappointing results overall. Splanchnic Doppler ultrasonography and the analysis of microbubble contrast agent kinetics with contrast-enhanced ultrasonography have shown better accuracy for the evaluation of patients with portal hypertension. A key advancement in the non-invasive evaluation of portal hypertension has been the introduction in clinical practice of methods able to measure stiffness in the liver, as well as stiffness/congestion in the spleen. According to the data published to date, it appears to be possible to rule out clinically significant portal hypertension in patients with cirrhosis (i.e., hepatic venous pressure gradient ≥ 10 mmHg) with a level of clinically-acceptable accuracy by combining measurements of liver stiffness and spleen stiffness along with Doppler ultrasound evaluation. It is probable that the combination of these methods may also allow for the identification of patients with the most serious degree of portal hypertension, and ongoing research is helping to ensure progress in this field.

Low-light-level therapy as a treatment for minimal hepatic encephalopathy: behavioural and brain assessment.

Minimal hepatic encephalopathy (MHE) has been shown to affect daily functioning, quality of life, driving and overall mortality. However, little is known about treating or diagnosing early impairments involved in MHE. We studied one of its precipitating factors, portal hypertension. The purpose was to evaluate an enhancement in neuronal metabolism through low-light-level therapy (LLLT) and whether this therapy has effects on behavioural task acquisition. Rats were trained to perform a stimulus-response task using the Morris water maze. Three groups of animals were used: a SHAM (sham-operated) group (n = 7), a portal hypertension (PH) group (n = 7) and a PH + LLLT group (n = 7). The triple portal vein ligation method was used to create an animal model of the early developmental phase of HE, and then the animals were exposed to 670 + 10 nm LED light at a dose of 9 J/cm2 once a day for 7 days. The metabolic activity of the brains was studied with cytochrome c oxidase histochemistry. There were differences in behavioural performance, with an improvement in the PH + LLLT group. Energetic brain metabolism revealed significant differences between the groups in all the brain structures analysed, except the anterodorsal thalamus. At the same time, in different brain networks, the PH group showed a more complicated relationship among the structures, while the SHAM and PH + LLLT groups had similar patterns. In this study, we provide the first preliminary insights into the validity of LLLT as a possible intervention to improve memory under minimal hepatic encephalopathy conditions.

Non-invasive assessment of portal hypertension using quantitative magnetic resonance imaging.

BACKGROUND & AIMS: Hepatic venous pressure gradient (HVPG) measurement is currently the only validated technique to accurately evaluate changes in portal pressure. In this study, we evaluate the use of non-contrast quantitative magnetic resonance imaging (MRI) as a surrogate measure of portal pressure. METHODS: Thirty patients undergoing HVPG measurement were prospectively recruited. MR parameters of longitudinal relaxation time (T1), perfusion of the liver and spleen (by arterial spin labelling), and blood flow in the portal, splanchnic and collateral circulation (by phase contrast MRI) were assessed. We estimated the liver stiffness measurement (LSM) and enhanced liver fibrosis (ELF) score. The correlation of all non-invasive parameters with HVPG was evaluated. RESULTS: The mean (range) HVPG of the patients was 9.8 (1-22) mmHg, and 14 patients (48%) had clinically significant portal hypertension (CSPH, HVPG ⩾10mmHg). Liver T1 relaxation time, splenic artery and superior mesenteric artery velocity correlated significantly with HVPG. Using multiple linear regression, liver T1 and splenic artery velocity remained as the two parameters in the multivariate model significantly associated with HVPG (R=0.90, p<0.001). This correlation was maintained in patients with CSPH (R=0.85, p<0.001). A validation cohort (n=10) showed this linear model provided a good prediction of HVPG. LSM and ELF score correlated significantly with HVPG in the whole population but the correlation was absent in CSPH. CONCLUSIONS: MR parameters related to both hepatic architecture and splanchnic haemodynamics correlate significantly with HVPG. This proposed model, confirmed in a validation cohort, could replace the invasive HVPG measurement. LAY SUMMARY: In patients with cirrhosis, the development and progression of portal hypertension is related to worse outcomes. However, the standard technique of assessing portal pressure is invasive and not widely used in clinical practice. Here, we have studied the use of non-invasive MRI in evaluating portal pressure. The MRI measures of liver architecture and blood flow in the splenic artery correlated well with portal pressure. Therefore, this non-invasive method can potentially be used to assess portal pressure in clinical trials and monitoring treatment in practice.

Quantitative Assessment of the Portal Pressure for the Liver Surgery Using Serological Tests.

OBJECTIVE: To establish a reliable equation to predict hepatic venous pressure gradient (HVPG) using serological tests for surgical patients with hepatocellular carcinoma (HCC). BACKGROUND: Accurate assessment of portal pressure for surgical patients with HCC is important for safe hepatic resection (HR). The HVPG is regarded as the most reliable method to detect portal hypertension. However, HVPG is not utilized in many medical centers due to invasiveness of procedure. METHODS: Between 2006 and 2008, 171 patients (Correlation cohort), who underwent liver surgery in a tertiary hospital, were enrolled. Preoperative measurements of the HVPG and serological tests were performed simultaneously. Correlation between the HVPG and serological tests were analyzed to establish an equation for calculated HVPG (cHVPG). Between 2008 and 2013, 510 surgical patients (Application cohort) were evaluated, and HR recommended when cHVPG < 10 mm Hg. The outcomes of HR were analyzed to evaluate reliability of the cHVPG for HR. RESULTS: In the correlation cohort, the equation for cHVPG was established using multivariate linear regression analysis; cHVPG (mm Hg) = 0.209 × [ICG-R15 (%)] - 1.646 × [albumin (g/dL)] - 0.01×[platelet count (10)] + 1.669 × [PT-INR] + 8.911. In the application cohort, 425 patients with cHVPG < 10 mm Hg underwent HR. Among them, 357 had favorable value of ICG-R15 < 20% (group A), and 68 had unfavorable value of ICG-R15 ≥ 20% (group B). There was no significant difference in patient demographics, tumor characteristics, operative outcome, and survival rates between group A and B. CONCLUSIONS: The equation for cHVPG of this study was established on statistical reliability. The cHVPG could be useful to predict portal pressure quantitatively for surgical patients with HCC using serological tests.