Shear wave elastography correlates with liver fibrosis scores in pediatric patients with liver disease

Metabolic dysfunction-associated steatotic liver disease in children

Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease, is the most common cause of chronic liver disease in children. MASLD encompasses a spectrum of liver disease and can be severe, with 10% of affected children presenting with advanced fibrosis. While biopsy remains the most accurate method for diagnosing and staging the disease, MRI proton density fat fraction and magnetic resonance elastography are the most reliable non-invasive measures for assessing steatosis and fibrosis, respectively. MASLD is associated with multiple comorbidities including type 2 diabetes, hypertension, dyslipidaemia, decreased bone mineral density, obstructive sleep apnoea, anxiety and depression. Currently, there are no pharmacological treatments available for children, highlighting the urgent need for paediatric clinical trials. A diet low in free sugars is promising for reducing steatosis and decreasing alanine aminotransferase, a surrogate marker for hepatic inflammation. Emerging data indicate that steatosis can be present in children under 6 years of age, which was previously considered rare. The intricate interplay of genetics may inform future therapeutics and prognostication, with the PNPLA3 gene showing the most evidence for association with the risk and severity of steatotic liver disease and steatohepatitis. MASLD is a complex disease affecting one in ten children and is associated with increased early mortality risk. More dedicated studies are needed in children to advance our understanding of this disease and find effective treatments.

Shear Wave Elastography in the Assessment of Liver Iron Overload in Children With Beta Thalassemia Major

ABSTRACT

Shear wave elastography (SWE) is an ultrasound method that effectively demonstrates liver fibrosis. This prospective study aimed to compare magnetic resonance imaging T2* and SWE results of the liver in children with thalassemia major (TM). Patients with TM who had regular follow-ups were included. SWE was performed first, followed by MRI T2*. In addition, a healthy control group of the same age group, known to have no liver disease, was recruited. For these participants, only SWE was performed, and their results were compared with the SWE parameters of the TM patients. The study included 38 patients and 25 individuals who made up the control group. The groups with mild, moderate, and severe iron overload according to MRI T2* were compared in terms of SWE with parameters, and no statistically significant difference was found. However, when comparing the SWE parameters between the control group and patients, the median, average, and standard values were found to be statistically significantly higher in the patient group (P < 0.001, P < 0.001, P = 0.026). When comparing MRI T2* results, the median, average, and standard values were found to be statistically significantly higher in the patients with normal and mild iron overload (P < 0.001, P < 0.001, P = 0.033). SWE is an effective, more accessible, and easy-to-apply method for demonstrating early changes in the liver in pediatric patients with TM. This study serves as a guide for more comprehensive studies that may investigate the effect of SWE in this patient group.

Evaluation of Hepatic Shear Wave Elastography to Assess Liver Fibrosis in Biliary Atresia Patients and Its Correlation with Liver Histology and Surgical Outcomes: A Prospective Observational Study

Introduction  The native liver survival in biliary atresia (BA) depends on various factors, and one of the crucial factors is the rate of progression of liver fibrosis after portoenterostomy, but there is no reliable investigation to assess it. This study evaluated shear wave elastography (SWE) to detect liver fibrosis in BA patients and assess its utility during follow-up. Materials and Methods  This was an observational study; SWE was done preoperatively and postoperatively at 3 and 6 months. The SWE values were analyzed to determine their correlations with preoperative liver histology as well as with postoperative SWE variation between different postoperative outcomes. Results  Twenty-one patients were included in the study; the preoperative SWE values were strongly correlated with liver biopsy grading ( p  < 0.001). At the 3 months postoperatively, SWE was done for 18 children: 12 in group A (patent bilioenteric drainage on hepatobiliary iminodiacetic acid scan) and 6 (nonpatent) in group B; mean SWE value was 12.8 and 17.3 kPa, respectively ( p  < 0.001). Ten children from group A underwent SWE 6 months postoperatively, and the mean value was 13.23 kPa. Conclusion  The SWE values correlate with liver histology grading, suggesting a reliable alternative to biopsy. Additionally, the baseline SWE values and their trend during follow-up can provide information on the disease's progression.

WFUMB Guideline/Guidance on Liver Multiparametric Ultrasound: Part 1. Update to 2018 Guidelines on Liver Ultrasound Elastography

The World Federation for Ultrasound in Medicine and Biology (WFUMB) endorsed the development of this document on multiparametric ultrasound. Part 1 is an update to the WFUMB Liver Elastography Guidelines Update released in 2018 and provides new evidence on the role of ultrasound elastography in chronic liver disease. The recommendations in this update were made and graded using the Oxford classification, including level of evidence (LoE), grade of recommendation (GoR) and proportion of agreement (Oxford Centre for Evidence-Based Medicine [OCEBM] 2009). The guidelines are clinically oriented, and the role of shear wave elastography in both fibrosis staging and prognostication in different etiologies of liver disease is discussed, highlighting advantages and limitations. A comprehensive section is devoted to the assessment of portal hypertension, with specific recommendations for the interpretation of liver and spleen stiffness measurements in this setting.

Shear wave elastography as a non-invasive tool for staging liver fibrosis in children: A study in Algerian pediatric patients

BACKGROUND

Traditionally, liver biopsy has been the gold standard for fibrosis staging. However, it is an invasive, expensive and uncomfortable procedure that is associated with the risk of complications. Thus, non-invasive methods such as shear wave elastography (SWE) have been developed as potential alternatives to liver biopsy. The aim of this study is to evaluate the diagnostic performance of SWE in pediatric patients with liver fibrosis, specifically in a group of Algerian children and to determine whether this method can be a reliable alternative to liver biopsy.

METHODS

This prospective, descriptive, monocentric study evaluated the non-invasive diagnostic performance of 2D-SWE in assessing liver fibrosis in pediatric patients. The assessment was carried out using various statistical methods, including Spearman's correlation coefficient, Kappa concordance coefficients, regression analysis, as well as the calculation of area under the receiver operating characteristic (AUROC) values and corresponding cut-off points based on the receiver operating characteristic (ROC) curve.

RESULTS

Our study found that 2D-SWE is strongly correlated with liver biopsy in estimating liver fibrosis in children, with a correlation coefficient greater than 0.8. Furthermore, the Kappa correlation coefficients exceeded 0.8, indicating a strong agreement between 2D-SWE and liver biopsy results. The AUROC value was not less than 0.9 for significant fibrosis and above (≥ F2), indicating that it has satisfactory diagnostic performance in detecting liver fibrosis in children.

CONCLUSION

2D-SWE shows promise as a non-invasive method for evaluating liver fibrosis in children, offering a potential alternative to liver biopsy. Larger studies are needed to substantiate the findings of this study and to confirm the accuracy and reliability of 2D-SWE for assessing liver fibrosis in children.

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.

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.

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.

Diagnostic Efficacy of Advanced Ultrasonography Imaging Techniques in Infants with Biliary Atresia (BA): A Systematic Review and Meta-Analysis

The early diagnosis of biliary atresia (BA) in cholestatic infants is critical to the success of the treatment. Intraoperative cholangiography (IOC), an invasive imaging technique, is the current strategy for the diagnosis of BA. Ultrasonography has advanced over recent years and emerging techniques such as shear wave elastography (SWE) have the potential to improve BA diagnosis. This review sought to evaluate the diagnostic efficacy of advanced ultrasonography techniques in the diagnosis of BA. Six databases (CINAHL, Medline, PubMed, Google Scholar, Web of Science (core collection), and Embase) were searched for studies assessing the diagnostic performance of advanced ultrasonography techniques in differentiating BA from non-BA causes of infantile cholestasis. The meta-analysis was performed using Meta-DiSc 1.4 and Comprehensive Meta-analysis v3 software. Quality Assessment of Diagnostic Accuracy Studies tool version 2 (QUADAS-2) assessed the risk of bias. Fifteen studies consisting of 2185 patients (BA = 1105; non-BA = 1080) met the inclusion criteria. SWE was the only advanced ultrasonography technique reported and had a good pooled diagnostic performance (sensitivity = 83%; specificity = 77%; AUC = 0.896). Liver stiffness indicators were significantly higher in BA compared to non-BA patients (p < 0.000). SWE could be a useful tool in differentiating BA from non-BA causes of infantile cholestasis. Future studies to assess the utility of other advanced ultrasonography techniques are recommended.

Nonalcoholic Steatohepatitis in Children

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in children. Although environmental factors are major contributors to early onset, children have both shared and unique genetic risk alleles as compared with adults with NAFLD. Treatment relies on reducing environmental risk factors, but many children have persistent diseases. No medications are approved specifically for the treatment of NAFLD, but some anti-obesity or diabetes treatments may be beneficial. Pediatric NAFLD increases the risk of diabetes and other cardiovascular risk factors. Long-term prospective studies are needed to determine the long-term risk of hepatic and non-hepatic morbidity and mortality in adulthood.

Characteristics of the gut microbiota in Bifidobacterium catenulatum LI10 pre-treated rats with lower levels of D-galactosamine-induced liver damage

AIMS

Liver damage has caused great illness in human beings. Bifidobacterium catenulatum LI10 has been determined with protective effect against D-galactosamine-induced liver damage. However, due to the sample limitation, the individual difference in its protective effect was not determined. The current study was designed to characterise the gut microbiota of LI10-pretreated rats with lower levels of liver damage.

METHODS AND RESULTS

A series of experiments and bioinformatic analyses were carried out. Two rat cohorts with different levels of liver damage were determined, i.e., Non-Severe and Severe cohorts. Six out of the seven measured liver function variables were lower in the Non-Severe cohort, while four cytokine variables also yielded differences between the two cohorts. The Non-Severe and Severe cohorts were determined with distinct gut microbiota, among which, ASV14_Parabacteroides and ASV7_Bacteroides were most associated with Non-Severe and Severe cohorts, respectively. Five phylotypes were determined as structural gatekeepers in the microbiota network of Non-Severe cohort, ASV135_Lachnospiraceae_NK4A136 of which contributed most to the stability of the network.

CONCLUSIONS

The relevant findings suggest that some gut bacteria could benefit the protective effect of LI10 on lowering the severity of rat liver damage.

SIGNIFICANCE AND IMPACT OF THE STUDY

The bacteria benefiting the protective effects of potential probiotics could be further investigated for future clinical application.

Shear Wave Elastography in the Differentiation of Nonfibrotic Versus Fibrotic Liver Disease in Children: A Prospective Study With Histological Correlation

To evaluate the diagnostic accuracy of ultrasound shear wave elastography (SWE) prospectively and to determine cutoff value for nonfibrotic liver tissue in children with suspected or established liver disease.

Methods

In 90 consecutive pediatric patients, standardized 2D-SWE was performed during general anesthesia and free breathing. Liver stiffness was estimated with SWE followed by a percutaneous biopsy from the corresponding area. SWE values were compared with histology with fibrosis scored according to Batts & Ludwig classification (grade 0-4 = F0-F4) and to hepatic biomarkers.

Results

Four patients with SWE interquartile range (IQR)/median ≥ 30% kPa were excluded. The remaining 86 children (59% males) had a mean age = 10.2 years (0.1-18). The distribution of individuals with median (min;max) SWE values (kPa) within each fibrosis grade were; F0[n = 10; 5.0(3.4;6.3)], F1[n = 24; 5.0(3.6;8.7)], F2[n = 32; 5.8(3.5;13.4)], F3[n = 12, 7.5(4.0;14.4)], and F4[n = 8; 12.5(6.6;21.0)]. There was a significant difference between fibrosis grades (0.03 > P < 0.002) except between F0 and F1 respectively between F1 and F2. The AuROC differentiating F0-1 from F2-4 was 0.77(95% CI: 0.67-0.87). A cutoff SWE value of ≤4.5 kPa yielded 90% sensitivity and 68% specificity to rule out significant fibrosis (F2-F4). Out of the 18 children (21%) with SWE value ≤4.5 kPa, 12 had grade F0-1 and 6 had F2, although including some confounders for increased SWE measurements as steatosis/hepatitis/cholestasis.

Conclusions

2D-SWE ultrasound can reliably distinguish no/mild (F0/F1) from moderate/severe (F2-F4) fibrosis in children with suspected/established liver disease with good sensitivity and acceptable specificity. Our results show that in pediatric patients, when the indication for biopsy is to rule out significant fibrosis, SWE can be considered an alternative.

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.

Performance of Imaging Techniques in Non-invasive Diagnosis of Non-alcoholic Fatty Liver Disease in Children: A Systematic Review and Meta-Analysis

BACKGROUND AND AIM

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in children. With the continuous emergence of various non-invasive diagnostic methods, imaging techniques have always been considered as potential alternative methods to liver biopsy. This study aimed to evaluate the diagnostic performance of imaging techniques so as to search for the most promising technology.

METHODS

We searched English and Chinese databases. English databases included Cochran library, Embase, PubMed, and Web of Science, while Chinese databases included the Wanfang database and China National Knowledge Internet.

RESULTS

Finally, 11 articles were included (12 studies, one of which included studies on both fibrosis and steatosis). Further, 26.2% of the participants had mild steatosis, 34.1% had moderate steatosis, and 34.9% had severe steatosis. Also, 64.0% had any fibrosis, 29.1% had significant fibrosis, 13.8% had advanced fibrosis, and 2.8% had cirrhosis. Irrespective of the grade of fibrosis, transient elastography (TE) had higher sensitivity (97-100%), whereas magnetic resonance elastography (MRE) had the lowest sensitivity (58-63%). The pooled sensitivity and specificity of imaging techniques in diagnosing steatosis were 89% (95% CI, 71-96) and 89% (95% CI, 72-96), and AUROC 0.95 (95% CI, 93-97), multifrequency magnetic resonance elastography-hepatic fat fraction (mMRE-HFF) had the highest sensitivity (87%, 95% CI 77-97), ultrasonography (US) had the lowest specificity (96%, 95% CI 92-98%).

CONCLUSION

Imaging techniques have a good diagnostic performance for children with NAFLD, especially the diagnosis of liver fibrosis based on ultrasound or magnetic resonance elastography. Compared with different imaging techniques, TE has the best performance in diagnosing significant fibrosis. Liver stiffness measurement (LSM) is expected to become a biological indicator for routine screening, dynamic monitoring of disease changes, and prognostic evaluation.

Diagnostic accuracy of fibrosis tests in children with non-alcoholic fatty liver disease: A systematic review

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in children. Even at young age, it can progress to liver fibrosis. Given the drawbacks of liver biopsy, there is a need for non-invasive methods to accurately stage liver fibrosis in this age group. In this systematic review, we evaluate the diagnostic accuracy of non-invasive methods for staging liver fibrosis in children with NAFLD.

METHODS

We searched MEDLINE, Embase, Web of Science and the Cochrane Library, for studies that evaluated the performance of a blood-based biomarker, prediction score or imaging technique in staging liver fibrosis in children with NAFLD, using liver biopsy as the reference standard.

RESULTS

Twenty studies with a total of 1787 NAFLD subjects were included, which evaluated three prediction scores, five simple biomarkers, two combined biomarkers and six imaging techniques. Most studies lacked validation. Substantial heterogeneity of studies and limited available study data precluded a meta-analysis of the few fibrosis tests evaluated in more than one study. The most consistent accuracy data were found for transient elastography by FibroScan®, ELF test and ultrasound elastography, with an area under the receiver operating characteristics curve varying between 0.92 and 1.00 for detecting significant fibrosis.

CONCLUSION

Due to the lack of validation, the accuracy and clinical utility of non-invasive fibrosis tests in children with NAFLD remains uncertain. As studies have solely been performed in tertiary care settings, accuracy data cannot directly be translated to screening populations.

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.

The evaluation of the use of 2D shear-wave ultrasound elastography in differentiation of clinically insignificant and significant liver fibrosis in pediatric age group

OBJECTIVE

To determine the accuracy of 2D shear-wave elastography (2D-SWE) in pediatric age group patients in differentiating clinically insignificant and significant liver fibrosis using METAVIR fibrosis scoring system as the gold standard.

INTRODUCTION

Liver biopsy has long been the gold standard in liver fibrosis diagnosis. However, due to probable complications and sampling variabilities, the need for more accurate and non-invasive techniques has increased. 2D-SWE is a non-invasive technique used in the evaluation of liver stiffness and utilized more and more in routine clinical practice with recent advances and researches.

MATERIALS AND METHODS

In this retrospective single-center study, we included 46 pediatric age group patients who had a liver parenchymal biopsy and 2D-SWE evaluation regardless of etiology. For 2D-SWE, the LOGIQ E9 system (GE Medical Systems, Wisconsin, USA) and, for histopathological evaluation, METAVIR fibrosis scoring system were utilized. Patients were further subgrouped as clinically insignificant (METAVIR Score F0-1) and significant (METAVIR Score F2-4). The Kolmogorov-Smirnov and Mann-Whitney U tests were employed for statistical analysis. The diagnostic accuracy of 2D-SWE was assessed, and cutoff values were set by ROC curve analysis.

RESULTS

kPa values were statistically different between clinically significant and insignificant fibrosis patient groups (p < 0.001). kPa value of 8.92 was designated as the best cutoff value according to the Youden Index.

CONCLUSION

2D-SWE is one of the non-invasive techniques in the evaluation of liver fibrosis. Our findings suggest that 2D-SWE accurately differentiate clinically insignificant and significant liver fibrosis.

Elastography for Pediatric Chronic Liver Disease: A Review and Expert Opinion

In adults with chronic liver diseases, ultrasound and magnetic resonance shear wave elastography (SWE) can replace liver biopsy in several clinical scenarios. Several guidelines on the use of ultrasound SWE for the adult population have been published. However, the number of publications in the pediatric population is limited, and available guidelines on SWE do not specifically address pediatric chronic liver diseases. In this article, we review the literature on the use of SWE for pediatric chronic liver diseases and provide expert opinion on how to use SWE, both ultrasound and magnetic resonance techniques, in the pediatric population.

The usefulness of noninvasive liver stiffness assessment using shear-wave elastography for predicting liver fibrosis in children

BACKGROUND

Pediatric patients with liver disease require noninvasive monitoring to evaluate the risk of fibrosis progression. This study aimed to identify the significant factors affecting liver stiffness values using two-dimensional shear-wave elastography (2D-SWE), and determine whether liver stiffness can predict the fibrosis stage of various childhood liver diseases.

METHODS

This study included 30 children (22 boys and 8 girls; mean age, 5.1 ± 6.1 years; range, 7 days-17.9 years) who had undergone biochemical evaluation, 2D-SWE examination, histopathologic analysis of fibrosis grade (F0 to F3), assessment of necroinflammatory activity, and steatosis grading between August 2016 and March 2020. The liver stiffness from 2D-SWE was compared between fibrosis stages using Kruskal-Wallis analysis. Factors that significantly affected liver stiffness were evaluated using univariate and multivariate linear regression analyses. The diagnostic performance was determined from the area under the receiver operating curve (AUC) values of 2D-SWE liver stiffness.

RESULTS

Liver stiffness at the F0-1, F2, and F3 stages were 7.9, 13.2, and 21.7 kPa, respectively (P < 0.001). Both fibrosis stage and necroinflammatory grade were significantly associated with liver stiffness (P < 0.001 and P = 0.021, respectively). However, in patients with alanine aminotransferase (ALT) levels below 200 IU/L, the only factor affecting liver stiffness was fibrosis stage (P = 0.030). The liver stiffness value could distinguish significant fibrosis (≥ F2) with an AUC of 0.950 (cutoff value, 11.3 kPa) and severe fibrosis (F3 stage) with an AUC of 0.924 (cutoff value, 18.1 kPa). The 2D-SWE values for differentiating significant fibrosis were 10.5 kPa (≥ F2) and 18.1 kPa (F3) in patients with ALT levels below 200 IU/L.

CONCLUSION

The liver stiffness values on 2D-SWE can be affected by both fibrosis and necroinflammatory grade and can provide excellent diagnostic performance in evaluating the fibrosis stage in various pediatric liver diseases. However, clinicians should be mindful of potential confounders, such as necroinflammatory activity or transaminase level, when performing 2D-SWE measurements for liver fibrosis staging.

Quantification of Hepatic and Splenic Stiffness After Fontan Procedure in Children and Clinical Implications

We aimed to investigate Fontan associated liver disease in children by shear wave elastography (SWE). This is a single-center, prospective case-control study included 41 patients with Fontan physiology and 30 healthy controls. Hepatic and splenic shear wave elasticity values were exhibited both as kPa and m/s. The mean hepatic SWE values of Fontan patients (n = 41; 15.8 ± 3.2 kPa or 2.5 ± 1.8 m/s) were significantly higher than the control group (n = 30; 5.59 ± 0.6 kPa or 1.37 ± 0.07 m/s) (P < 0.001). The mean splenic SWE values of Fontan patients were (25.6 ± 4.61 kPa or 2.85 ± 0.22 m/s) significantly higher than the control group (15.9 ± 1.44 kPa or 2.29 ± 0.1 m/s) (P < 0.001). There were statistically significant positive correlations among the follow-up duration after the Fontan procedure with NT-proBNP (P = 0.008, r = 1) and prothrombin time (P = 0.009, r = 0.4) as well as the hepatic SWE values with alanine aminotransferase (P = 0.039, r = 0.32), gamma-glutamyl transferase (P = 0.045, r = 0.31), and PT (P = 0.011, r = 0.39). There has been statistically significant moderate positive correlations of splenic stiffness values with PT (P = 0.047, r = 0.34), and INR (P = 0.038, r = 0.35). The sensitivity and specificity of liver stiffness cutoff value as 11.1 kPa for detection of Fontan associated liver disease were 95% and 100%, respectively. The hepatic and splenic stiffness increase independently in Fontan patients due to parenchymal disease. Hepatic SWE is a reliable and noninvasive predictor of early hepatic alterations that could not be detected only by biochemical results or routine ultrasound examinations.

Shear wave velocity by quantitative acoustic radiation force impulse in the placenta of normal and high-risk pregnancy

Background

Traditionally, the placental functional integrity is suggested by indirect ultrasound measurements like fetal growth, amniotic fluid index, and uterine and umbilical artery Doppler indices. Only recently the elasticity of the placenta is studied as a measure of placental consistency and biomechanical prosperities and may reflect the placental function. Shear wave velocity is the quantitative parameter of the shear wave elastography. A high-risk pregnancy is a situation which puts the mother, the fetus, or both at greater risk than a normal pregnancy.

Results

The shear wave velocity (SWV) showed no significant difference between the placenta of normal pregnancies in the second and third trimesters (0.85 ± 0.43 m/s and 0.89 ± 0.57 m/s, respectively). The placenta of patients with preeclampsia/eclampsia had high SWV in the second and third trimesters (2.13 ± 1.48 m/s and 2.23 ± 1.48 m/s) with a highly significant difference from the normal placenta (P < 0.001). The placentas with abnormal location (placenta previa) and penetration (placenta accreta) had higher SWV than the placenta of normal pregnancies. The mean SWV for placenta previa was 1.1 ± 0.74 m/s and 1.3 ± 0.81 m/s in the second and third trimesters, respectively, with a mildly significant difference with the normal placenta. The placenta accreta shows high mean SWV in the second and third trimesters (1.6 ± 0.65 m/s and 1.961.6 ± 0.65, respectively) which differed significantly (P < 0.001) from SWV in the normal placenta in the second and third trimesters.

Conclusion

Shear wave velocity measurement as the quantitative parameter of acoustic radiation force impulse (ARFI) elastography reflects the placental elasticity in normal and high-risk pregnancies. The SWV increases in conditions like hypertension, preeclampsia, maternal renal disease, and diabetes and reflects the structural and biomechanical abnormalities in such diseases. High shear wave velocity correlates with the incidence of growth restriction and abnormal Doppler parameters especially in the hypertensive disease. The virtual touch quantification (VTQ) can be used as a complementary diagnostic and prognostic tool in high-risk pregnancy.

Two-dimensional ultrasound shear wave elastography for identifying and staging liver fibrosis in pediatric patients with known or suspected liver disease: a clinical effectiveness study

BACKGROUND

Ultrasound shear wave elastography (SWE) measures liver stiffness noninvasively, but few studies have defined cutoff values for detecting liver fibrosis in pediatric patients using 2-D ultrasound SWE.

OBJECTIVE

To evaluate the diagnostic performance of 2-D ultrasound SWE and define cutoff values for liver fibrosis in pediatric patients, using Canon (Toshiba) Aplio ultrasound systems.

MATERIALS AND METHODS

This was an institutional review board-approved retrospective study of patients (≤18 years old) who had undergone both liver 2-D ultrasound SWE and percutaneous liver biopsy within 6 months. Liver biopsies were staged using the METAVIR (fibrosis) scoring system. Continuous data were compared using the Mann-Whitney U test. Receiver operating characteristic (ROC) curve analysis was used to evaluate diagnostic performance.

RESULTS

Forty-six patients, with a median age of 11.5 years (interquartile range: 8.0-14.3 years), were included. Twenty-three patients were male (50%). Twenty-seven patients had a METAVIR fibrosis score of F0-1, and 19 patients had a score of F2-4. For differentiating METAVIR F0-1 from F2--4, the area under the ROC (AuROC) was 0.75 (95% confidence interval [CI]: 0.60-0.90). A cutoff of >1.89 m/s yielded sensitivity of 73.7% (95% CI: 51.2-88.2) and specificity of 77.8% (95% CI: 59.2-89.4). For the subset of patients without histological hepatic steatosis (n=35), the AuROC was 0.86 (95% CI: 0.71-1.0). The same cutoff of >1.89 m/s yielded a sensitivity of 80.0% (95% CI: 54.8-93.0) and specificity of 95.0% (95% CI 76.4-99.7).

CONCLUSION

Two-dimensional ultrasound SWE distinguishes patients with no/mild fibrosis from those with moderate/severe fibrosis with good sensitivity and specificity. Diagnostic performance is comparable to that published for magnetic resonance elastography and is likely adversely impacted by steatosis.

Advances in Diagnostic Imaging in Pediatric Gastroenterology

PURPOSE OF REVIEW

The purpose is to provide a review of cross-sectional imaging updates in the assessment of gastrointestinal diseases, relevant to clinical practice and research.

RECENT FINDINGS

New magnetic resonance imaging contrast agents (Eovist) are taken up by hepatocytes and excreted via the biliary tree. As such, a lesion will retain contrast only if hepatocytes are present, which aids in refining the differential diagnosis. Magnetic resonance enterography is a method for non-invasively diagnosing and following various GI conditions, predominantly inflammatory bowel disease. Contrast-enhanced ultrasound uses gas-filled microbubbles providing superb temporal resolution most notably in the arterial phase, which aids in differentiating lesions. Elastography is a new technique which assesses stiffness of liver for evaluating fibrosis. These new techniques provide more accurate diagnoses and information, often limiting ionizing radiation exposure from other modalities. While ultrasound will still remain the initial imaging modality, familiarity with these other options is valuable for appropriate pathology workup.