Ultrasound-based liver elastography: current results and future perspectives

Quantitative Liver Imaging in Children

ABSTRACT

In children and adults, quantitative imaging examinations determine the effectiveness of treatment for liver disease. However, pediatric liver disease differs in presentation from liver disease in adults. Children also needed to be followed for a longer period from onset and have less control of their bodies, showing more movement than adults during imaging examinations, which leads to a greater need for sedation. Thus, it is essential to appropriately tailor and accurately perform noninvasive imaging tests in these younger patients. This article is an overview of updated imaging techniques used to assess liver disease quantitatively in children. The common initial imaging study for diffuse liver disease in pediatric patients is ultrasound. In addition to preexisting echo analysis, newly developed attenuation imaging techniques have been introduced to evaluate fatty liver. Ultrasound elastography is also now actively used to evaluate liver conditions, and the broad age spectrum of the pediatric population requires caution to be taken even in the selection of probes. Magnetic resonance imaging (MRI) is another important imaging tool used to evaluate liver disease despite requiring sedation or anesthesia in young children because it allows quantitative analysis with sequences such as fat analysis and MR elastography. In addition to ultrasound and MRI, we review quantitative imaging methods specifically for fatty liver, Wilson disease, biliary atresia, hepatic fibrosis, Fontan-associated liver disease, autoimmune hepatitis, sinusoidal obstruction syndrome, and the transplanted liver. Lastly, concerns such as growth and motion that need to be addressed specifically for children are summarized.

Medical comorbidities in bipolar disorder (BIPCOM): clinical validation of risk factors and biomarkers to improve prevention and treatment. Study protocol

BACKGROUND

BIPCOM aims to (1) identify medical comorbidities in people with bipolar disorder (BD); (2) examine risk factors and clinical profiles of Medical Comorbidities (MC) in this clinical group, with a special focus on Metabolic Syndrome (MetS); (3) develop a Clinical Support Tool (CST) for the personalized management of BD and medical comorbidities.

METHODS

The BIPCOM project aims to investigate MC, specifically MetS, in individuals with BD using various approaches. Initially, prevalence rates, characteristics, genetic and non-genetic risk factors, and the natural progression of MetS among individuals with BD will be assessed by analysing Nordic registers, biobanks, and existing patient datasets from 11 European recruiting centres across 5 countries. Subsequently, a clinical study involving 400 participants from these sites will be conducted to examine the clinical profiles and incidence of specific MetS risk factors over 1 year. Baseline assessments, 1-year follow-ups, biomarker analyses, and physical activity measurements with wearable biosensors, and focus groups will be performed. Using this comprehensive data, a CST will be developed to enhance the prevention, early detection, and personalized treatment of MC in BD, by incorporating clinical, biological, sex and genetic information. This protocol will highlight the study's methodology.

DISCUSSION

BIPCOM's data collection will pave the way for tailored treatment and prevention approaches for individuals with BD. This approach has the potential to generate significant healthcare savings by preventing complications, hospitalizations, and emergency visits related to comorbidities and cardiovascular risks in BD. BIPCOM's data collection will enhance BD patient care through personalized strategies, resulting in improved quality of life and reduced costly interventions. The findings of the study will contribute to a better understanding of the relationship between medical comorbidities and BD, enabling accurate prediction and effective management of MetS and cardiovascular diseases.

TRIAL REGISTRATION

ISRCTN68010602 at https://www.isrctn.com/ISRCTN68010602 . Registration date: 18/04/2023.

Suboptimal reliability of FIB-4 and NAFLD-fibrosis scores for staging of liver fibrosis in general population

Background and Aim

The burden and incidence of liver cirrhosis are increasing worldwide. Early detection of liver fibrosis would help in early interventions and preventing the progression of fibrosis and cirrhosis. The accepted noninvasive markers for liver fibrosis staging, namely fibrosis-4 (FIB-4) and nonalcoholic fatty liver disease fibrosis score (NFS), have shown inconsistent performance for detecting the fibrosis stage. We aimed to evaluate the efficacy of FIB-4 score and NFS for the detection of liver fibrosis in the general population.

Methods

From a general population referred from a single, community-based family-physician clinic, we included study participants between the ages of 45 and 65 years, with no knowledge of liver disease and no record of alcohol consumption. Liver fibrosis was evaluated by the FIB-4 score and NFS using shear wave elastography (SWE) or transient elastography (TE) measurements as a reference.

Results

A total of 76 participants (aged 61.5 ± 0.37 years, 33% females) were included in the study cohort. We observed a nonsignificant correlation between liver stiffness measurement (LSM) and FIB-4 and NFS (r = 0.1, P = 0.37; r = 0.16, P = 0.15, respectively). Our results showed that only 5.2% with FIB-4 >3.25 and 9.7% with NFS >0.675 had LSM >12 kPa. The compatibility of fibrosis staging was 55% between FIB-4 score and LSM and only 18% between NFS and LSM.

Conclusion

We found that FIB-4 and NFS are unreliable tools for liver fibrosis estimation in the general population. There is a need for more reliable noninvasive methods for the early detection of liver fibrosis.

Portal hypertension in common variable immunodeficiency disorders - a single center analysis on clinical and immunological parameter in 196 patients

Background

Liver manifestations and in particular portal hypertension (PH) contribute significantly to morbidity and mortality of patients with common variable immunodeficiency disorders (CVID). Screening strategies and early detection are limited due to the lack of specific diagnostic tools.

Methods

We evaluated clinical, immunological, histological, and imaging parameters in CVID patients with clinical manifestation of portal hypertension (CVID+PH).

Results

Portal hypertension was present in 5.6% of CVID patients and was associated with high clinical burden and increased mortality (18%). Longitudinal data on clinical and immunological parameters in patients before and during clinically manifest portal hypertension revealed a growing splenomegaly and increasing gamma-glutamyl transferase (GGT) and soluble interleukin 2 receptor (SIL-2R) levels with decreasing platelets over time. While ultrasound of the liver failed to detect signs of portal hypertension in most affected patients, transient elastography was elevated in all patients. All CVID+PH patients had reduced naïve CD45RA+CD4+ T-cells (mean of 6,2%). The frequency of severe B-lymphocytopenia (Euroclass B-) was higher in CVID+PH patients. The main histological findings included lymphocytic infiltration, nodular regenerative hyperplasia-like changes (NRH-LC), and porto(-septal) fibrosis.

Conclusion

CVID patients with lower naïve CD45RA+CD4+ T-cells or severely reduced B-cells might be at higher risk for portal hypertension. The combination of biochemical (increasing sIL-2R, GGT, and decreasing platelets) and imaging parameters (increasing splenomegaly) should raise suspicion of the beginning of portal hypertension.

Multisample Ultrasound Point Shear Wave Elastography of the Liver: Repeatability and Agreement With Conventional Point Shear Wave Elastography

OBJECTIVE

To characterize the technical performance of a multisample ultrasound point shear wave elastography (pSWE) technique that allows 15 individual measurements of liver stiffness in a single acquisition.

METHODS

In 56 overweight and obese adults, research ultrasound examinations were performed using conventional pSWE and multisample pSWE (Sequoia; Siemens Healthineers). Five independent measurements were acquired with the conventional technique over five consecutive breath holds (5C1 and DAX transducers). A single multisample acquisition (DAX transducer) of up to 15 unique measurements was acquired during a single breath hold. All imaging was performed before (baseline) and after a "coffee break" (repeat). Median liver stiffness measurements between techniques and between baseline and repeat imaging were compared using Pearson correlation (r) and intra-class correlation (ICC) coefficients.

RESULTS

Mean participant age was 33.7 ± 11.4 years; 40 participants were female. There was high correlation between conventional pSWE measurements obtained using the 5C1 and DAX transducers at baseline (r = .75 [95% CI: 0.61-0.85], P < .0001) and repeat (r = .88 [95% CI: 0.78-0.92], P < .0001). There was moderate agreement between conventional pSWE measurements obtained using the 5C1 and DAX transducers at baseline (ICC = 0.69 [95% CI: 0.52-0.81]), and good agreement at repeat (ICC = 0.81 [95% CI: 0.65-0.90]). There was moderate correlation (r = .59 [95% CI: 0.39-0.74], P < .0001) and moderate agreement (ICC = 0.58 [95% CI: 0.38-0.73]) between baseline conventional and multisample pSWE measurements acquired using the DAX transducer; there was high correlation (r = .73 [95% CI: 0.57-0.83], P < .0001) and moderate agreement (ICC = 0.72 [95% CI: 0.56-0.82] between techniques at repeat. There was moderate correlation (r = .65 [95% CI: 0.46-0.78], P < .0001) and moderate agreement (ICC = 0.64 [95% CI: 0.45-0.77]) between baseline and repeat multisample pSWE measurements.

CONCLUSIONS

Multisample pSWE, allowing up to 15 measurements in a single breath hold, showed moderate to high correlation and moderate agreement with conventional pSWE.

The role of sound touch elastography in assessment of liver fibrosis in chronic liver disease keeping APRI as the reference standard

PURPOSE

The study aims to determine the role of Sound Touch Elastography [STE] technique in staging liver fibrosis and predicting clinically significant gastro-esophageal varices among patients with chronic liver disease [CLD] keeping aspartate aminotransferase to platelet ratio index [APRI] as the reference standard.

METHODS

A prospective short-term study including 60 eligible patients with CLD were staged as non-significant fibrosis [NSF], significant fibrosis [SF] and cirrhosis [C] based on APRI values. STE was performed on each patient obtaining multiple readings as per pre-defined standards. The intra-observer reliability between each measurement and its association with APRI staging was evaluated using relevant statistical variables. Further, Youden's index was used to define the optimum cut-off values on STE in differentiating the stages of fibrosis and in predicting clinically significant gastro-esophageal varices.

RESULTS

Based on APRI cut-off values, 41.7% [n = 25] of the study population had cirrhosis, while 45% [n = 27] had significant fibrosis and 13.3% [n = 8] had NSF. The STE values in kPa showed a positive correlation with APRI values [(rs) = 0.837, p < 0.001]. The intra-class correlation estimates based on a mean rating [k = 5] was found to be 0.97 [0.95-0.99], implying an excellent agreement between the measurements. Optimum cut-off values in staging SF and C were 7.26 kPa [J = 0.73, sensitivity-85.19%, specificity-87.5%; 95% CI] and 13.79 kPa [J = 0.84, sensitivity-96.0%, specificity-88.89%; 95% CI]. The AUROC for each of these stages were 0.926 [0.785-0.987] and 0.976 [0.890-0.999], respectively. 23.3% [n = 14] of the study population had clinically significant gastro-esophageal varices with a value above 18.84 kPa [J = 0.88] showing a sensitivity of 92.85% and a specificity of 95.65% in predicting the same.

CONCLUSION

The novel STE technique shows good accuracy in staging liver fibrosis as determined by APRI values and in prediction of clinically significant gastro-esophageal varices with excellent reliability. It shows promising prospects and can be integrated widely in clinical practice for assessment and staging of fibrosis in CLD.

Visualizing tactile feedback: an overview of current technologies with a focus on ultrasound elastography

Tissue elasticity remains an essential biomarker of health and is indicative of irregularities such as tumors or infection. The timely detection of such abnormalities is crucial for the prevention of disease progression and complications that arise from late-stage illnesses. However, at both the bedside and the operating table, there is a distinct lack of tactile feedback for deep-seated tissue. As surgical techniques advance toward remote or minimally invasive options to reduce infection risk and hasten healing time, surgeons lose the ability to manually palpate tissue. Furthermore, palpation of deep structures results in decreased accuracy, with the additional barrier of needing years of experience for adequate confidence of diagnoses. This review delves into the current modalities used to fulfill the clinical need of quantifying physical touch. It covers research efforts involving tactile sensing for remote or minimally invasive surgeries, as well as the potential of ultrasound elastography to further this field with non-invasive real-time imaging of the organ's biomechanical properties. Elastography monitors tissue response to acoustic or mechanical energy and reconstructs an image representative of the elastic profile in the region of interest. This intuitive visualization of tissue elasticity surpasses the tactile information provided by sensors currently used to augment or supplement manual palpation. Focusing on common ultrasound elastography modalities, we evaluate various sensing mechanisms used for measuring tactile information and describe their emerging use in clinical settings where palpation is insufficient or restricted. With the ongoing advancements in ultrasound technology, particularly the emergence of micromachined ultrasound transducers, these devices hold great potential in facilitating early detection of tissue abnormalities and providing an objective measure of patient health.

Emerging Applications of Extracardiac Ultrasound in Critically Ill Cardiac Patients

Point-of-care ultrasound has evolved as an invaluable diagnostic modality and procedural guidance tool in the care of critically ill cardiac patients. Beyond focused cardiac ultrasound, additional extracardiac ultrasound modalities may provide important information at the bedside. In addition to new uses of existing modalities, such as pulsed-wave Doppler ultrasound, the development of new applications is fostered by the implementation of additional features in mid-range ultrasound machines commonly acquired for intensive care units, such as tissue elastography, speckle tracking, and contrast-enhanced ultrasound quantification software. This review explores several areas in which ultrasound imaging technology may transform care in the future. First, we review how lung ultrasound in mechanically ventilated patients can enable the personalization of ventilator parameters and help to liberate them from mechanical ventilation. Second, we review the role of venous Doppler in the assessment of organ congestion and how tissue elastography may complement this application. Finally, we explore how contrast-enhanced ultrasound could be used to assess changes in organ perfusion.

Predicting Post-hepatectomy Liver Failure Preoperatively for Child-Pugh A5 Hepatocellular Carcinoma Patients by Liver Stiffness

BACKGROUND

Post-hepatectomy liver failure (PHLF) represents the major source of mortality after liver resection (LR) in hepatocellular carcinoma (HCC) patients. Child-Pugh (CP) score 5 is always considered to indicate a normal liver function but represents a heterogeneous population with a considerable number suffering from PHLF. The present study aimed to access the ability of liver stiffness (LS) measured by two-dimensional shear wave elastography (2D-SWE) to predict PHLF in HCC patients with a CP score of 5.

METHODS

From August 2018 to May 2021, 146 HCC patients with a CP score of 5 who underwent LR were reviewed. The patients were randomly divided into training (n = 97) and validation (n = 49) groups. Logistic analyses were conducted for the risk factors and a linear model was built to predict the development of PHLF. The discrimination and calibration were assessed in the training and validation cohorts by the areas under the receiver operating characteristic curve (AUC).

RESULTS

Analyses revealed that the minimum of LS (Emin) higher than 8.05 (p = 0.006, OR = 4.59) and future liver remnant / estimated total liver volume (FLR/eTLV) (p < 0.001, OR < 0.01) were independent predictors of PHLF in HCC patients with CP score 5, and the AUC calculated by the model based on them for differentiation of PHLF in the training and validation group was 0.78 and 0.76, respectively.

CONCLUSION

LS was associated with the development of PHLF. A model combining Emin and FLR/eTLV showed proper ability in predicting PHLF in HCC patients with a CP score of 5.

Comparison Between Different Manufacturers' 2-D and Point Shear Wave Elastography Techniques in Staging Liver Fibrosis in Chronic Liver Disease Using Liver Biopsy as the Reference Standard: A Prospective Study

The purpose of this study was to assess the utility of 2-D shear wave elastography (SWE) in assessing liver fibrosis in patients with chronic liver disease by comparing its performance with that of point shear wave elastography (pSWE) using liver histological staging as the reference standard. In this ethics committee-approved, single-institution prospective study, pSWE and 2-D SWE velocity measurements were obtained in 121 adult patients (age: 18-70 y, median: 45 y) immediately before a liver biopsy for chronic liver disease. Shear wave velocity (SWV) and Ishak scores were compared using the Kruskal-Wallis test, Spearman's correlation and receiver operating characteristic (ROC) curve analysis. Youden's index was used to determine the optimal cutoff point. There was no technical failure using pSWE and 2-D SWE. The mean difference for SWV between pSWE and 2-D SWE was 0.0223 (limits of agreement: -1.1009, 1.1145). Values for both pSWE and 2-D SWE were significantly correlated with fibrosis stage (Spearman's ρ = 0.606, p < 0.0001; ρ = 0.722, p < 0.001 respectively). The area under the ROC curve differentiating F ≥3 was 0.855 (95% confidence interval: 0.778-0.932) for pSWE and 0.884 (95% CI: 0.817-0.951) for 2-D SWE. The AUC for differentiating F ≥5 was 0.890 (95% CI: 0.826-0.954) for pSWE and 0.926 (95% CI: 0.88-0.973) for 2-D SWE. This study indicates that 2-D SWE provides feasible and accurate assessment of liver fibrosis, comparable to that provided by pSWE from two different manufacturers' machines.

Liver Disease Assessment in Children with Fontan and Glenn Surgeries for Univentricular Hearts—The Role of Elastography and Biochemical Fibrosis Markers

Background: Children born with single-ventricle hearts require surgery in order to survive. Liver fibrosis is a known complication of Fontan surgery for univentricular hearts. Methods: In this study on 13 post-Fontan and 21 post-Glenn patients, we used elastography (shearwave and transient elastography) as well as serum biochemical fibrosis markers to evaluate the degree of liver fibrosis in comparison to 32 controls. Results: The mean Emedian and Vmedian values determined by shear wave elastography in the Fontan Group were significantly higher than the controls (4.85 kPa vs. 3.91 kPa and 1.25 m/s vs. 1.12 m/s, respectively). Fontan patients had significantly increased Fibrotest, Actitest, AST-to-Platelet Ratio index, ALT and GammaGT levels compared to controls. For post-Glenn patients, the mean Emedian and Vmedian values were similar to healthy controls, whereas the Fibrotest, Actitest and AST-to-Platelet Ratio index were significantly increased. Using transient elastography, we found significantly higher values for Emedian and Vmedian in Fontan patients compared to Glenn patients. Conclusions: Elastography and biochemical fibrosis markers are valuable non-invasive tools for screening and monitoring liver fibrosis in patients with Fontan and Glenn interventions.

Comparison of Quantitative Liver US and MRI in Patients with Liver Disease

Background Quantitative US techniques can be used to identify changes of liver disease, but data regarding their diagnostic performance and relationship to MRI measures are sparse. Purpose To define associations between quantitative US and MRI measures of the liver in children, adolescents, and young adults with liver disease and to define the predictive ability of quantitative US measures to detect abnormal liver stiffening and steatosis defined with MRI. Materials and Methods In this prospective study, consecutive patients aged 8-21 years and known to have or suspected of having liver disease and body mass index less than 35 kg/m² underwent 1.5-T MRI and quantitative liver US during the same visit at a pediatric academic medical center between April 2018 and December 2020. Acquired US parameters included shear-wave speed (SWS) and attenuation coefficient, among others. US parameters were compared with liver MR elastography and liver MRI proton density fat fraction (PDFF). Pearson correlation, multiple logistic regression, and receiver operating characteristic curve analyses were performed to assess associations and determine the performance of US relative to that of MRI. Results A total of 44 study participants (mean age, 16 years ± 4 [SD]; age range, 8-21 years; 23 male participants) were evaluated. There was a positive correlation between US SWS and MR elastography stiffness (r = 0.73, P < .001). US attenuation was positively correlated with MRI PDFF (r = 0.45, P = .001). For the prediction of abnormal (>2.8 kPa) liver shear stiffness, SWS (1.56 m/sec [7.3 kPa] cutoff) had an area under the receiver operating characteristic curve (AUC) of 0.95 with 91% sensitivity (95% CI: 71, 99) (20 of 22 participants) and 95% specificity (95% CI: 76, 99) (20 of 21 participants). For the prediction of abnormal (>5%) liver PDFF, US attenuation (0.55 dB/cm/MHz cutoff) had an AUC of 0.75 with a sensitivity of 73% (95% CI: 39, 94) (eight of 11 participants) and a specificity of 73% (95% CI: 55, 86) (24 of 33 participants). Conclusion In children, adolescents, and young adults with known or suspected liver disease, there was moderate to high correlation between US shear-wave speed (SWS) and MR elastography-derived stiffness. US SWS predicted an abnormal liver shear stiffness with high performance. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Khanna and Alazraki in this issue.

Reliability of Performing Multiparametric Ultrasound in Adult Livers

PURPOSE

The aim of the study was to test inter-observer and intra-observer reliability of measuring multiparametric ultrasound in adult livers.

METHODS

We prospectively measured shear wave velocity (SWV, m/s), shear wave dispersion slope (SWD, m/s/kHz), attenuation coefficient (ATI, dB/cm/MHz), normalized local variance (NLV), and echo intensity ratio of liver to kidney (L/K ratio) in 21 adults who underwent liver magnetic resonance imaging-proton density fat fraction (MRI-PDFF). Intraclass correlation coefficient and 95% Bland-Altman limits of agreement (95% LOA) were used to analyze intra- and inter-observer reproducibility.

RESULTS

Based on liver MRI-PDFF, 21 participants (8 men and 13 women, mean age 55 years) were divided into group 1 (11 normal livers, MRI-PDFF <5%) and group 2 (10 steatotic livers, MRI-PDFF ≥5%). ICCs for intra-observer repeatability and inter-observer reproducibility in measuring multiple ultrasound parameters in both normal and steatotic livers were above 0.75. However, 95% confidence interval for measuring SWD in all livers and L/K ratio in normal livers was 0.38-0.90 and 0.47-0.91, respectively. Differences in SWV, SWD, ATI, NLV, L/K ratio, and MRI-PDFF between participants with and without hepatic steatosis were significant (p < .05), whereas serum biomarkers and body mass index were not (p > .05), based on a two-tailed t-test.

CONCLUSIONS

The results suggest that the repeatability and reproducibility for measuring liver SWV, ATI, and NLV are moderate to excellent, while those for SWD and L/K ratio are poor. Standardized machine settings, scanning protocols, and operator training are suggested in performing multiparametric ultrasound of the liver.

Assessing Liver Fibrosis Using the FIB4 Index in the Community Setting

Liver disease is frequently asymptomatic, challenging early identification in the primary care setting. The fibrosis 4 (FIB4) index is a liver fibrosis biomarker that is a potential alternative to liver biopsy for diagnosing and managing liver disease. This study aimed to calculate the FIB4 index for screening individuals at high risk of liver disease at the community level. This was a retrospective real-world study analyzing blood and serum test results from a central laboratory. The primary outcome was the number of individuals within each risk category for hepatic fibrosis: high risk (FIB4 ≥ 3.25) and low risk (FIB4 < 1.3). The analysis included samples from 31,753 patients, of which 18,102 were aged 40 to 75 years. In these patients, the FIB4 index had been explicitly requested in 1852 (10.2%) cases and estimated ad hoc in the rest. Of the 263 (1.5%) cases with FIB4 ≥ 3.25, the FIB4 index was requested in 46 (17.5%), and 52 (19.8%) showed evidence of liver fibrosis in their medical records, while the rest did not report any data regarding liver fibrosis. FIB4 is a simple score that can play a role as a "red flag" for early identification of patients at high risk of advanced liver fibrosis and their referral to specialized care.

Application of Magnetic Resonance Imaging in Liver Biomechanics: A Systematic Review

MRI-based biomechanical studies can provide a deep understanding of the mechanisms governing liver function, its mechanical performance but also liver diseases. In addition, comprehensive modeling of the liver can help improve liver disease treatment. Furthermore, such studies demonstrate the beginning of an engineering-level approach to how the liver disease affects material properties and liver function. Aimed at researchers in the field of MRI-based liver simulation, research articles pertinent to MRI-based liver modeling were identified, reviewed, and summarized systematically. Various MRI applications for liver biomechanics are highlighted, and the limitations of different viscoelastic models used in magnetic resonance elastography are addressed. The clinical application of the simulations and the diseases studied are also discussed. Based on the developed questionnaire, the papers' quality was assessed, and of the 46 reviewed papers, 32 papers were determined to be of high-quality. Due to the lack of the suitable material models for different liver diseases studied by magnetic resonance elastography, researchers may consider the effect of liver diseases on constitutive models. In the future, research groups may incorporate various aspects of machine learning (ML) into constitutive models and MRI data extraction to further refine the study methodology. Moreover, researchers should strive for further reproducibility and rigorous model validation and verification.

Reliability of performing ultrasound derived SWE and fat fraction in adult livers

PURPOSE

The aim of the study was to test the reproducibility of performing conventional point shear wave elastography (pSWE), auto-pSWE, and ultrasound derived fat fraction (UDFF) in adult livers.

METHODS

The Institutional Review Board approved the study and all participants provided written informed consent. Conventional pSWE (obtaining 10 measurements through 10 acquisitions), auto-pSWE (automatically obtaining 15 measurements by a single acquisition), and UDFF (one measurement obtained by one acquisition) of the liver were prospectively performed in 21 participants (10 men, 11 women, mean age 63y) by senior and junior operators in February-May 2021. Shear wave velocity (SWV, m/s) of the liver was measured by conventional pSWE and auto-pSWE. Intraclass correlation coefficient (ICC) and Bland-Altman limits of agreement were used to test intra-observer repeatability and inter-observer reproducibility in measuring pSWE, auto-pSWE, and UDFF.

RESULTS

ICC for testing intra-observer repeatability and inter-observer reproducibility in performing pSWE, auto-pSWE, and UDFF was >0.85 (95% confidence interval 0.85-0.99). The mean difference of 95% Bland-Altman limits of agreement was -0.02 (upper 0.09, lower -0.12) and the correlation of SWV measured between conventional pSWE and auto-pSWE methods was strong (r² = 0.87).

CONCLUSION

Our results suggest good repeatability and reproducibility in measuring UDFF and SWV in adult livers. The auto-pSWE has higher reliability, reproducibility and time efficacy in measuring SWV of adult livers when compared to conventional pSWE method.

Cascade of care for children and adolescents with chronic hepatitis C. World J Gastroenterol 2021;27:1117-1131. [PMID: 33828389 PMCID: PMC8006101 DOI: 10.3748/wjg.v27.i12.1117]

Chronic hepatitis C virus (HCV) infection presents a significant global public health burden. In 2015, over 400000 deaths worldwide were attributed to HCV infection. This led the World Health Organization (WHO) in 2016 to set the ambitious goal of eliminating HCV by 2030. Adult-centered guidelines have been established in order to provide direction for healthcare professionals, allowing integration of the newest screening policies and therapeutic strategies into their practices. However, for children and adolescents, HCV is a significant, unrecognized public health problem. HCV infection rates in the United States in women of childbearing age and those who are pregnant have increased in parallel with the rising opioid epidemic. An estimated 29000 women with HCV infection gave birth each year from 2011 to 2014 in the United States, with approximately 1700 of their infants being infected with HCV. Newer HCV-specific therapeutics, namely direct acting antivirals (DAA), has brought a new and highly successful approach to treatment of hepatitis C. Recent studies have confirmed similar levels of effectiveness and safety of DAA therapies in the pediatric population. Thus, an enhanced cascade of care, which should include the population under 18 years of age, can help achieve the WHO goal by focusing on elimination in the youngest populations. This review will present an overview of the natural history, clinical features, and management of HCV in children and adolescents.

Quantitative, noninvasive MRI characterization of disease progression in a mouse model of non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) is an increasing cause of chronic liver disease characterized by steatosis, inflammation, and fibrosis which can lead to cirrhosis, hepatocellular carcinoma, and mortality. Quantitative, noninvasive methods for characterizing the pathophysiology of NASH at both the preclinical and clinical level are sorely needed. We report here a multiparametric magnetic resonance imaging (MRI) protocol with the fibrogenesis probe Gd-Hyd to characterize fibrotic disease activity and steatosis in a common mouse model of NASH. Mice were fed a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) to induce NASH with advanced fibrosis. Mice fed normal chow and CDAHFD underwent MRI after 2, 6, 10 and 14 weeks to measure liver T1, T2*, fat fraction, and dynamic T1-weighted Gd-Hyd enhanced imaging of the liver. Steatosis, inflammation, and fibrosis were then quantified by histology. NASH and fibrosis developed quickly in CDAHFD fed mice with strong correlation between morphometric steatosis quantification and liver fat estimated by MRI (r = 0.90). Sirius red histology and collagen quantification confirmed increasing fibrosis over time (r = 0.82). Though baseline T1 and T2* measurements did not correlate with fibrosis, Gd-Hyd signal enhancement provided a measure of the extent of active fibrotic disease progression and correlated strongly with lysyl oxidase expression. Gd-Hyd MRI accurately detects fibrogenesis in a mouse model of NASH with advanced fibrosis and can be combined with other MR measures, like fat imaging, to more accurately assess disease burden.