Bidimensional shear-wave elastography for assessing liver fibrosis in children: a proposal of reference values that correlate with the histopathological Knodell-Ishak score

Correlation of Liver Fibrosis using Noninvasive Transient Elastography with Histological Staging in Infants with Cholestasis - A Prospective Analytical Study

Aims

This study primarily aimed to correlate liver fibrosis (LF) assessed by transient elastography (TE) using liver stiffness measurement (LSM score) with liver biopsy fibrosis scoring (METAVIR score) in biliary atresia (BA). Secondary objectives were to assess the diagnostic accuracy of TE in distinguishing BA from other causes of neonatal cholestasis (NC) and the correlation of preoperative LSM score with surgical outcomes 3 months post Kasai portoenterostomy.

Methodology

Infants under 6 months with conjugated hyperbilirubinemia (July 2022-February 2024) were cases and age- and gender-matched healthy infants served as controls. Cases were evaluated using predefined standard diagnostic tests and TE using Fibroscan® Expert 630 (Echosens) device was additionally performed preoperatively and 3 months postoperatively. METAVIR scoring was calculated on liver histopathology.

Results

Fifty-one NC patients (28 boys, 23 girls) were included. A preoperative LSM ≥ 11.4 predicted significant fibrosis (METAVIR score - F3/F4) with 94% sensitivity and 46% specificity (P = 0.053). A preoperative LSM ≥ 13.2 fairly predicted the presence of BA with 74% sensitivity, 71% specificity (P = 0.006), and 72.5% diagnostic accuracy. Median preoperative LSM (interquartile range) for clearance of jaundice (COJ) (14.1 [10.28-18.48]) versus no clearance (15.7 [12.1-35]) showed no statistical difference (P = 0.359).

Discussion and Conclusion

TE is an effective noninvasive screening tool to differentiate BA from other causes of NC with a cutoff of >13.2 kPa. The predictive value of TE for postoperative COJ and complications like cholangitis based on the preoperative LF measurements cannot be commented on based on our results.

Progress in the diagnosis and treatment of graft fibrosis after liver transplantation

Liver transplantation (LT) is considered one of the best treatments for patients with end‐stage liver diseases. However, some patients with no significant clinical manifestations or abnormal laboratory tests still experience graft fibrosis during postoperative follow‐up, which is often recognized by graft histopathology. Graft fibrosis can lead to graft dysfunction, thereby reducing the survival time of the recipient and even requiring re‐transplantation. Currently, noninvasive methods are widely applied in the assessment of hepatic and allograft fibrosis. Although both noninvasive diagnostic models based on laboratory examination indicators and elastography technology that can quantify liver stiffness have some value in the evaluation of fibrosis, the diagnostic accuracy and characteristics of these various methods vary and cannot replace liver biopsy completely. In recent years, some liver‐protective drugs and proprietary Chinese traditional medicines have been proven to delay or reverse chronic liver fibrosis. Nevertheless, their efficacy and safety for LT recipients need to be further verified. This article reviews the diagnosis and treatment of graft fibrosis after LT to provide a reference for improving the overall survival rate of LT recipients.

Liver fibrosis assessment in pediatric population - can ultrasound elastography be an alternative method to liver biopsy? A systematic review

Liver diseases of various etiologies are becoming increasingly common in the pediatric population. So far, the gold diagnostic standard in these disorders is liver biopsy. This procedure is invasive, painful and requires general anesthesia in this group of patients. Due to the continuous development of new research techniques, such as liver elastography, it is necessary to evaluate them in the context of their diagnostic usefulness. Ultrasound elastography, as a quick and effective method, is being used more and more often in the assessment and monitoring of liver dysfunction in both adults and children. There are several techniques of liver elastography, such as transient elastography, shear wave elastography consisting of various subtypes such as two-dimensional shear wave elastography, acoustic radiation force impulse and point shear wave elastography, which differ in terms of the measurement technique and the achieved results. The purpose of our review was to determine whether techniques of liver elastography could replace liver biopsy. Although now, based on the analyzed papers, elastography cannot replace liver biopsy, in our opinion, the role of this tool in monitoring pediatric patients with liver diseases will grow in the coming years.

Performance of two-dimensional shear wave elastography for detecting advanced liver fibrosis and cirrhosis in patients with biliary atresia: a systematic review and meta-analysis

BACKGROUND

Two-dimensional shear wave elastography (2D-SWE) has been proposed for detecting liver fibrosis in biliary atresia.

OBJECTIVES

To assess the performance of 2D-SWE for detecting advanced liver fibrosis and cirrhosis in patients with biliary atresia.

MATERIALS AND METHODS

Five electronic databases were searched to identify studies investigating the performance of 2D-SWE for diagnosing liver fibrosis in biliary atresia in children. We constructed the summary receiver operating characteristic (SROC) curves of 2D-SWE for detecting advanced liver fibrosis and cirrhosis, and then calculated the area under the SROC curves (AUROCs).

RESULTS

Six studies with 470 patients (ages 55 days to 6.6 years) were included. The median correlation coefficient of 2D-SWE with pathological liver fibrosis stages was 0.779 (range: 0.443‒0.813). The summary AUROCs for advanced liver fibrosis and cirrhosis were 0.929 and 0.883, respectively. The summary sensitivity and specificity of 2D-SWE for advanced liver fibrosis were 88% (95% confidence interval [CI]: 80‒94%) and 85% (95% CI: 77‒91%) with I values of 0% and 45.6%, respectively, and for cirrhosis were 80% (95% CI: 72‒87%) and 82% (95% CI: 77‒86%) with I values of 12.9% and 0%, respectively. The diagnostic odds ratio (DOR) of 2D-SWE for advanced liver fibrosis and cirrhosis were 40.3 (95% CI: 18.2‒89.4) and 18.9 (95% CI: 11.2‒31.7), respectively. For preoperative detection of cirrhosis, the pooled AUROC, sensitivity, specificity, and DOR based on the four 2D-SWE studies were 0.877, 79% (95% CI: 71‒86%), 82% (95% CI: 77‒86%), and 17.58 (95% CI: 10.35‒29.85), respectively.

CONCLUSIONS

Results show that 2D-SWE has potential as a non-invasive tool for detecting advanced liver fibrosis and cirrhosis in patients with biliary atresia.

Ultrasound Elastography in Children

Ultrasound elastography is a novel ultrasound technique, being extensively researched in children in the last decade. It measures tissue elasticity with the observation of tissue response after an external stimulus. From research to clinical practice, ultrasound elastography has evolved significantly in liver fibrosis evaluation in children; however, several other applications of the technique are available in both clinical practice and research environments. Practically, in children any organ can be assessed, including the brain in early ages, along with muscle and connective tissue elasticity evaluation, spleen, kidney, skin, lymphatic tissue, etc. The elastography method, age, body mass index and technical points should be considered when performing ultrasound elastography. This review highlights its vast potential as a diagnostic tool in the pediatric population, where ultrasound is a dominant imaging tool; however, the indications and exam protocol for its clinical use in several fields in pediatrics have yet to be elucidated.

Liver fibrosis in children: a comprehensive review of mechanisms, diagnosis, and therapy

Chronic liver disease incidence is increasing among children worldwide due to a multitude of epidemiological changes. Most of these chronic insults to the pediatric liver progress to fibrosis and cirrhosis to different degrees. Liver and immune physiology differs significantly in children from adults. Because most of pediatric liver diseases have no definitive therapy, a better understanding of population and disease-specific fibrogenesis is mandatory. Furthermore, fibrosis development has prognostic significance and often guide treatment. Evaluation of liver fibrosis continues to rely on the gold-standard liver biopsy. However, many high-quality studies put forward the high diagnostic accuracy of numerous diagnostic modalities in this setting. Herein, we summarize and discuss the recent literature on fibrogenesis with an emphasis on pediatric physiology along with a detailed outline of disease-specific signatures, noninvasive diagnostic modalities, and the potential for antifibrotic therapies.

Magnetic resonance elastography in evaluation of liver fibrosis in children with chronic liver disease

BACKGROUND

Magnetic resonance elastography (MRE) has been used to stage liver fibrosis in adults. We aimed to assess the agreement between the Ishak scoring system and magnetic resonance elastography-measured liver stiffness (MRE-LS) in children. This study included all the children who underwent abdominal MRE and liver biopsies between February 2018 and January 2021. The correlation between MRE-LS and Ishak fibrosis stage, MRE parameters, and clinical and biochemical markers affecting this relationship was investigated.

RESULTS

A total of 52 patients (31 male; a median age of 11.8 years) were included in the study. The MRE-LS values were significantly different between Ishak fibrosis stages (p = 0.036). With a cut-off value of 2.97 kilopascals, MRE-LS had sensitivity, specificity, PPV, NPV and accuracy values of 90.9%, 82.9%, 58.8%, 97.1%, and 84.6%, respectively, for differentiating mild/moderate fibrosis (F0, 1, 2, 3) from severe fibrosis (F ≥ 4). Although MRE-LS was moderately correlated with Ishak fibrosis score and histological activity index and weakly correlated with aspartate aminotransferase, hepatic steatosis, and R2*, only Ishak fibrosis score was a significant predictor of MRE-LS. MRE-measured spleen stiffness was weakly correlated with the Ishak fibrosis score.

CONCLUSIONS

MRE has high sensitivity and specificity for evaluating liver fibrosis in children. MRE may be used to evaluate liver fibrosis in pediatric patients.

Validation of attenuation imaging coefficient, shear wave elastography, and dispersion as emerging tools for non-invasive evaluation of liver tissue in children

Introduction

The number of children with acute and chronic liver disease is rising. Moreover, liver involvement may be limited to subtle changes in organ texture especially in early childhood and some syndromic conditions, such as ciliopathies. Attenuation imaging coefficient (ATI), shear wave elastography (SWE), and dispersion (SWD) are emerging ultrasound technologies providing data about attenuation, elasticity, and viscosity of liver tissue. This additional and qualitative information has been correlated with certain liver pathologies. However, limited data are available for healthy controls and have mainly been raised in adults.

Methods

This prospective monocentric study was conducted at a university hospital with a specialization in pediatric liver disease and transplantation. Between February and July 2021, 129 children aged 0-17.92 years were recruited. Study participants attended outpatient clinics due to minor illnesses excluding liver or cardiac diseases, acute (febrile) infections or other conditions affecting liver tissue and function. ATI, SWE, and SWD measurements were performed on an Aplio i800 (Canon Medical Systems) with an i8CX1 curved transducer by two different investigators with long-standing experience in pediatric ultrasound according to a standardized protocol.

Results

Considering multiple potential covariates, we derived percentile charts for all 3 devices relying on the Lambda-Mu-Sigma (LMS) approach. 112 children were considered for further analysis, excluding those with abnormal liver function and under-/overweight (BMI SDS<-1.96/> 1.96, respectively). Age range was 0-17.92 years (mean 6.89±0.50SD), 58% were male. The mean duration of the ultrasound examination (basic ultrasound plus SWE, SWD, and ATI) was 6.67±0.22 minutes and it was well tolerated in 83% (n=92) of cases. While ATI was related to age, SWD was found to depend on BMI SDS, and SWE on abdominal wall thickness and sex. ATI correlated with neither SWE nor SWD, but SWE was correlated with SWD.

Conclusions

Our study provides norm values and reference charts for ATI, SWE, and SWD considering important covariates including age, sex and, BMI. This may help to implement these promising tools into imaging diagnostics of liver disease and to improve the diagnostic relevance of liver ultrasound. In addition, these noninvasive techniques proved to be time-effective and highly reliable, which make them ideal for application in children.

Diagnosis of liver cirrhosis with two-dimensional shear wave elastography in biliary atresia before Kasai portoenterostomy

PURPOSE

To evaluate the application value of two-dimensional shear wave elastography (2D-SWE) for non-invasive diagnosis of liver cirrhosis (LC) in patients with biliary atresia (BA) before Kasai portoenterostomy (KP), and the cutoff value of liver stiffness measurement (LSM) for diagnosing LC.

METHODS

The clinical data of 51 patients with BA who were diagnosed via surgery and pathological results from May 2017 to December 2018 in the department of general surgery, Beijing Children's Hospital, Capital Medical University, were retrospectively analyzed. The liver tissue specimens obtained during KP were evaluated according to the METAVIR criteria. The LSM was obtained using the 2D-SWE technique before KP.

RESULTS

There was a grade positive correlation between LSM and METAVIR staging, and the Spearman correlation coefficient was 0.432 (P = 0.002). The AUC for 2D-SWE diagnosing LC (METAVIR score S = 4) in patients with BA before KP was 0.843 (95% confidence interval 0.736 ~ 0.950). The best cutoff value was 16.05 kPa, and the corresponding sensitivity was 75.0%, specificity was 83.7%, positive predictive value (PPV) was 46.1%, negative predictive value (NPV) was 94.7%, and the accuracy was 82.4%.

CONCLUSION

2D-SWE can be used to noninvasively diagnose LC in patients with BA before KP, and the cutoff value is 16.05 kPa.

Noninvasive Pediatric Liver Fibrosis Measurement: Two-Dimensional Shear Wave Elastography Compared With Transient Elastography

OBJECTIVES

Although transient elastography (TE) is the primary noninvasive method for assessing liver fibrosis, its use remains to be validated in children. This study aims to evaluate the agreement between two-dimensional ultrasound shear wave elastography (2D-SWE) and TE to assess pediatric liver stiffness method.

METHODS

During the 18-month study, we prospectively included 101 consecutive children (median age: 8.5 years, range: 1 month to 17 years) who required TE for medical reasons, and in whom 2D-SWE measurement was performed within a 3-month follow-up during a routine ultrasound. Liver elasticity values were classified according to the Metavir score using published pediatric norms for TE and according to the manufacturer's reference values for 2D-SWE. The Spearman's correlation coefficient was used to assess the relationship between the elasticity measured by the two techniques. Concordance was described by the Bland-Altman method.

RESULTS

A strong correlation (rho = 0.70, p < 0.001) was found between 2D-SWE and TE for the elasticity measures. The strength of correlation was higher among patients older than 6 years (rho = 0.79, p < 0.001). Concordance between liver fibrosis stages assessed by these techniques was moderate [weighted kappa = 0.46, (95% CI: 0.35-0.57)]. When considering stages over F2, 2D-SWE diagnostic performances showed a sensitivity of 85% (95% CI: 74-92) and a specificity of 57% (95% CI: 42-70) compared with TE.

CONCLUSION

Measurements of the liver stiffness using 2D-SWE and TE are strongly correlated. The moderate concordance between these techniques for assessing the liver fibrosis stage provides evidence against alternating between these methods during follow-up of patients with the chronic liver diseases.

Diagnostic accuracy of two-dimensional shear wave elastography in detecting hepatic fibrosis in children with autoimmune hepatitis, biliary atresia and other chronic liver diseases

BACKGROUND

Although fibrosis is the main determinant of liver stiffness, other disease-related factors usually disregarded in studies on liver elastography, such as inflammation and cholestasis, may influence liver stiffness.

OBJECTIVE

To evaluate the accuracy of two-dimensional (2-D) shear wave elastography in assessing liver fibrosis in children with chronic liver disease by controlling for the confounding role of several disease- and patient-related factors.

MATERIALS AND METHODS

Three disease groups were studied: 1) various chronic liver diseases, 2) autoimmune hepatitis and 3) biliary atresia. The METAVIR (meta-analysis of histological data in viral hepatitis) score was used for fibrosis staging and grading of necroinflammatory activity. Multiple linear regression was used to evaluate the relationship between liver stiffness measurements and disease-related factors. The diagnostic accuracy of elastography for predicting fibrosis stages was assessed by calculating the area under the receiver operating characteristic curves.

RESULTS

The various chronic liver diseases group (n=32; 7.1±4.9 [mean±standard deviation] years) showed liver stiffness of 8.9±5.0 (mean±standard deviation) kPa, the autoimmune hepatitis group (n=33;  8.1±4.4 years) of  7.1±2.7 kPa, and the biliary atresia group (n=19; 0.2±0.1 years) of 19.7±15.2 kPa. Liver stiffness measurements differed across METAVIR fibrosis categories in all disease groups. The highest values were found in biliary atresia, at fibrosis stages ≥F2 (F2: 12.4±1.6 kPa, F3: 17.8±2 kPa, F4: 41.5±12.4 kPa). Liver stiffness was strongly associated only with fibrosis (P<0.0001) in various chronic liver diseases, but with necroinflammatory activity (P<0.0001) and fibrosis (P=0.002) in autoimmune hepatitis, and with age (P<0.0001), fibrosis (P<0.0001) and cholestasis (P=0.009) in biliary atresia. Optimal cutoffs for detecting advanced fibrosis (≥F3) were 16 kPa (area under curve: 0.98; sensitivity: 87.5%; specificity: 96.7%) in biliary atresia and 8.7 kPa (area under curve: 0.98; sensitivity: 93.8%; specificity: 96.1%) in other chronic liver diseases.

CONCLUSION

Two-dimensional shear wave elastography is reliable in assessing liver fibrosis in children with chronic liver diseases.