Quick assessment with controlled attenuation parameter for hepatic steatosis in children based on MRI-PDFF as the gold standard

Controlled attenuation parameter (CAP): the clinical value based on MRI-PDFF in children with obesity

OBJECTIVES

Controlled attenuation parameter (CAP) is a noninvasive and quantitative method to evaluate hepatic steatosis, which is not well evaluated in children. The aim of this study was to examine the diagnostic value of CAP for hepatic steatosis in children with obesity based on MR proton density fat fraction (PDFF).

METHODS

About 108 pediatric patients with nonalcoholic fatty liver disease (NAFLD) who were assessed for PDFF, CAP, and other laboratory results were enrolled. In this study, pediatric patients were separated for the obese group (n=80) and the severe obese group (n=28). Hepatic steatosis grades (0-3) were classified according to PDFF using cutoff values of 6.4 , 17.4, and 22.1 %.

RESULTS

There are significant differences in CAP between the obese and severe obese groups (p<0.05). CAP showed a good correlation with PDFF in pediatric patients with NAFLD for diagnosing hepatic steatosis using a cutoff value of 265 dB/m (p<0.001). Meanwhile, ALT significantly outperforms CAP in receiver-operating curve (ROC) analysis for diagnosing hepatic steatosis grades. The diagnostic accuracy of CAP for steatosis is 77.8 %, and the diagnostic accuracy of ALT for steatosis is 83.3 %.

CONCLUSIONS

While CAP holds promise as a diagnostic tool for pediatric NAFLD, its diagnostic performance warrants some caution. The potential of CAP is evident; however, ALT emerges as a simpler and more accurate measure for detecting hepatic steatosis in children. Further research is essential to determine the optimal role of CAP in pediatric NAFLD diagnosis and management.

Ultrasound screening of paediatric non-alcoholic fatty liver disease (NAFLD): A critical literature review

INTRODUCTION

Paediatric NAFLD is an increasing global health concern, which can be effectively managed with early detection. Screening, using accurate, affordable, and accessible tests is recommended, however, there is currently no consensus on the most appropriate tests. Although ultrasound techniques are widely used, their performance against reference tests have not been fully assessed.

METHODS

A literature search of related databases for peer-reviewed original articles published from January 2010-March 2024 was conducted. Appropriate tools were used to systematise and document the search results and selected studies were quality assessed and critically appraised. Extracted data was subjected to thematic analysis and narrative synthesis.

RESULTS

Eighteen articles met the inclusion criteria. B-mode and Quantitative ultrasound techniques were compared against MR spectroscopy, MRI-PDFF and Liver biopsy.

CONCLUSION

Liver echogenicity and Steato-scores were the B-mode methods used. The former was less effective, with a maximum reported sensitivity of 70%. The latter reached up to 100% sensitivity, and >80% specificity. Ultrasound performed better with moderate-severe steatosis. There was not enough evidence to support steatosis grading, possibly due to small sample sizes and lack of established cut-off values. QUS (Quantitative Ultrasound)) methods including Continuous Attenuation Parameter (CAP), Attenuation Coefficient (AC), Ultrasound derived fat fraction (UDFF), Tissue Scatter Imaging (TSI) Hepato-Renal Index (HRI), Heterogeneity Index (HIA), Computer Assisted Ultrasound (CAUS) and Picture Archiving and Communication System (PACS-based Image analysis performed better than B-mode methods. Although QUS demonstrated excellent performance, with sensitivity and specificity of up to 100%, this will require further verification before implementation in practice.

PRACTICE IMPLICATIONS

Ultrasound techniques can effectively be used for paediatric NAFLD screening, especially in higher-risk subjects. The steato-scores method is currently recommendable for this, with excellent potential for the use of QUS, after cut-off values and validation requirements have been addressed.

An international multidisciplinary consensus on pediatric metabolic dysfunction-associated fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is highly prevalent in children and adolescents, particularly those with obesity. NAFLD is considered a hepatic manifestation of the metabolic syndrome due to its close associations with abdominal obesity, insulin resistance, and atherogenic dyslipidemia. Experts have proposed an alternative terminology, metabolic dysfunction-associated fatty liver disease (MAFLD), to better reflect its pathophysiology. This study aimed to develop consensus statements and recommendations for pediatric MAFLD through collaboration among international experts.

METHODS

A group of 65 experts from 35 countries and six continents, including pediatricians, hepatologists, and endocrinologists, participated in a consensus development process. The process encompassed various aspects of pediatric MAFLD, including epidemiology, mechanisms, screening, and management.

FINDINGS

In round 1, we received 65 surveys from 35 countries and analyzed these results, which informed us that 73.3% of respondents agreed with 20 draft statements while 23.8% agreed somewhat. The mean percentage of agreement or somewhat agreement increased to 80.85% and 15.75%, respectively, in round 2. The final statements covered a wide range of topics related to epidemiology, pathophysiology, and strategies for screening and managing pediatric MAFLD.

CONCLUSIONS

The consensus statements and recommendations developed by an international expert panel serve to optimize clinical outcomes and improve the quality of life for children and adolescents with MAFLD. These findings emphasize the need for standardized approaches in diagnosing and treating pediatric MAFLD.

FUNDING

This work was funded by the National Natural Science Foundation of China (82070588, 82370577), the National Key R&D Program of China (2023YFA1800801), National High Level Hospital Clinical Research Funding (2022-PUMCH-C-014), the Wuxi Taihu Talent Plan (DJTD202106), and the Medical Key Discipline Program of Wuxi Health Commission (ZDXK2021007).

Clinical research of fibroscan ‒ TE-CAP at noninvasive diagnosis of hepatic steatosis in children

BACKGROUND & AIMS

The authors assess the diagnostic accuracy of the Transient Elastography-Controlled Attenuation Parameter (TE-CAP) in children of Southern China.

METHODS

105 obese or overweight children and adolescents were enrolled in the diagnostic test of TE-CAP assessment of hepatic steatosis using MRI-PDFF. Hepatic steatosis grades S0-S3 were classified. Statistical correlation, agreement and consistency between methods were evaluated. The diagnostic efficiency of TE-CAP was evaluated. The authors used the cutoff value of TE-CAP to detect hepatic steatosis in another 356 children.

RESULTS

The Area Under Curve (AUC) of TE-CAP for grade ≥ S1, ≥ S2, and ≥ S3 steatosis were 0.975, 0.984, and 0.997, respectively. For detecting ≥ S1 steatosis, TE-CAP had a sensitivity of 96 % and a specificity of 97 %. For detecting ≥ S2 steatosis, TE-CAP had a sensitivity of 97 % and a specificity of 93 %. For detecting ≥ S3 steatosis, TE-CAP had a sensitivity of 1 and a specificity of 94 %. TE-CAP and MRI-PDFF had a linear correlation (r = 0. 0.87, p < 0.001). The hepatic steatosis was identified in 40.2 % (143/356) of children in which the obesity and overweight were 69.8 % (113/162) and 40.0 % (18/45).

CONCLUSION

TE-CAP showed excellent diagnostic accuracy in pediatric hepatic steatosis.

Diagnostic Accuracy of Transient Elastography in Hepatosteatosis in Youth With Obesity

Context

Steatotic liver disease is common but overlooked in childhood obesity; diagnostic methods are invasive or expensive.

Objective

We sought to determine the diagnostic accuracy of vibration-controlled transient elastography (VCTE) compared with magnetic resonance imaging (MRI) in adolescents with obesity and high risk for hepatosteatosis.

Methods

Baseline data in 3 clinical trials enrolling adolescents with obesity were included (NCT03919929, NCT03717935, NCT04342390). Liver fat was assessed using MRI fat fraction and VCTE-based controlled attenuation parameter (CAP). Hepatosteatosis was defined as MRI fat fraction ≥5.0%. The area under the receiver-operating characteristic curves (AUROCs) for CAP against MRI was calculated, and optimal CAP using the Youden index for hepatosteatosis diagnosis was determined.

Results

Data from 82 adolescents (age 15.6 ± 1.4 years, body mass index 36.5 ± 5.9 kg/m2, 81% female) were included. Fifty youth had hepatosteatosis by MRI (fat fraction 9.3% ; 95% CI 6.7, 14.0), and 32 participants did not have hepatosteatosis (fat fraction 3.1%; 95% CI 2.2, 3.9; P < .001). The hepatosteatosis group had higher mean CAP compared with no hepatosteatosis (293 dB/m; 95% CI 267, 325 vs 267 dB/m; 95% CI 248, 282; P = .0120). A CAP of 281 dB/m had the highest sensitivity (60%) and specificity (74%) with AUROC of 0.649 (95% CI 0.51-0.79; P = .04) in the entire cohort. In a subset of participants with polycystic ovary syndrome (PCOS), a CAP of 306 dB/m had the highest sensitivity (78%) and specificity (52%) and AUROC of 0.678 (95% CI 0.45-0.90; P = .108).

Conclusion

CAP of 281 dB/m has modest diagnostic performance for hepatosteatosis compared with MRI in youth with significant obesity. A higher CAP in youth with PCOS suggests that comorbidities might affect optimal CAP in hepatosteatosis diagnosis.

Prevalence and incidence of MAFLD and associated anthropometric parameters among prepubertal children of the Shanghai Birth Cohort

BACKGROUND AND AIM

Metabolic dysfunction-associated fatty liver disease (MAFLD) is the most common chronic liver disease in adolescent and adult population. However, the epidemiologic data of MAFLD in prepubertal children remain limited. This study aimed to investigate the prevalence and incidence of MAFLD and assess the role of anthropometric parameters in identifying and predicting MAFLD in this population.

METHODS

Children from the Shanghai Birth Cohort Study who underwent an 8-year follow-up with anthropometric measurements and transient elastography FibroScan-502 examination (M probe, Echosens, Paris, France) were enrolled. Some of them also completed a 5-year follow-up. Diagnosis of fatty liver disease (FLD) was based on the controlled attenuation parameter (CAP) value exceeding 248 dB/m, and MAFLD was defined as FLD combined with obesity or central obesity. Receiver operating characteristic (ROC) curve analysis was conducted to evaluate the diagnostic accuracy of anthropometric parameters for MAFLD.

RESULTS

A total of 848 children (431 boys) from the Shanghai Birth Cohort Study were followed up for 8 years, and among them, 385 children (189 boys) also participated in the 5-year follow-up. The prevalence of FLD and MAFLD at 5 years old was 3.90% and 0.52%, respectively, while at 8 years old, the prevalence rates increased to 5.07% for FLD and 3.42% for MAFLD. The 8-year-old children with MAFLD exhibited significantly higher weight, body mass index (BMI), chest circumference, waist circumference, hip circumference, waist-to-height ratio, waist-to-hip ratio, and liver stiffness measurement compared to those without MAFLD (all p < 0.05). The incidence rates of FLD and MAFLD at 8 years old, considering the 5-year follow-up data, were 3.78% (14/370) and 3.13% (12/383), respectively. Obese or centrally obese children at 5 years old had a higher incidence of FLD and MAFLD at the 8-year follow-up. Waist circumference and BMI showed significant associations with the presence and incidence of MAFLD, respectively, with the largest AUC values in ROC curve analysis. In addition, chest circumference was significantly associated with MAFLD in obese children.

CONCLUSION

This study provides insights into the incidence and prevalence of MAFLD in prepubertal children. It underscores the importance of anthropometric parameters in identifying and predicting MAFLD in this population. Further research encompassing a broader age range and incorporating these indicators and additional metabolic markers is necessary to enhance the understanding and management of MAFLD in children.

Effects of short-term supervised exercise training on liver fat in adolescents with obesity: a randomized controlled trial

OBJECTIVE

The objective of this study was to quantify the effects of a 4-week, supervised, high-intensity interval training (HIIT) on intrahepatic triglyceride content (IHTG, percentage), cardiorespiratory fitness (CRF), and cardiometabolic markers in adolescents with obesity.

METHODS

A total of 40 adolescents (age 13-18 y, BMI 36.7 ± 5.8 kg/m2 ) at risk for metabolic dysfunction-associated steatotic liver disease (MASLD) based on obesity and elevated Fibroscan measured controlled attenuation parameter (CAP) scores were randomized to HIIT three times a week for 4 weeks (n = 34) or observation (control; n = 6). Liver magnetic resonance imaging proton-density fat-fraction (MRI-PDFF), CAP, oral glucose tolerance test, serum alanine aminotransferase, dual-energy x-ray absorptiometry, and CRF tests were performed before and after intervention. Within- and between-group differences were compared.

RESULTS

A total of 13 (38%) and 4 (66%) children had MASLD by MRI-PDFF (IHTG ≥ 5%) in the HIIT and control groups, respectively. The implemented HIIT protocol had no impact on CRF or IHTG (baseline 5.26%, Δ = -0.31 percentage points, 95% CI: -0.77 to 0.15; p = 0.179), but it decreased the 2-h glucose concentration (baseline 116 mg/dL, Δ = -11 mg/dL; 95% CI: -17.6 to -5.5; p < 0.001). When limiting the analysis to participants with MASLD (n = 17), HIIT decreased IHTG (baseline 8.81%, Δ = -1.05 percentage points, 95% CI: -2.08 to -0.01; p = 0.048). Between-group comparisons were not different.

CONCLUSIONS

The implemented exercise protocol did not reduce IHTG, but it led to modest improvement in markers of cardiometabolic health.

Clinical epidemiology of non-alcoholic fatty liver disease in children and adolescents. The LiverKids: Study protocol

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is rapidly increasing alongside overweight and obesity, not only in adults but also in children and adolescents. It is unknown what impact the development of NAFLD in childhood may have in later life. The importance of early detection and treatment lies in its potential for progression to cirrhosis, liver cancer and liver-related death, as well as its associated extrahepatic comorbidities. Vibration-Controlled Transient Elastography (VCTE) with Controlled Attenuation Parameter (CAP) is an effective, non-invasive and safe diagnostic method to estimate the degree of fibrosis and steatosis in the liver, but little is known about its applicability in the paediatric population.

AIMS

1) To assess the prevalence of significant liver fibrosis (Liver Stiffness Measurement (LSM) ≥6.5 kPa) using VCTE, and that of non-alcoholic fatty liver disease (≥225 dB/m) using CAP in children and adolescents. 2) To determine the optimal cut-off points of the CAP to achieve maximum concordance with the Magnetic Resonance Imaging (MRI) findings in the diagnosis of mild, moderate and severe NAFLD in children and adolescents.

METHODS

Cross-sectional population-based study which will include 2,866 subjects aged between 9 and 16 years. Participants will undergo: anamnesis, physical examination, blood extraction, VCTE, MRI and questionnaires on socio-demographic data, personal and family medical history and lifestyle assessment.

APPLICABILITY AND RELEVANCE

The study aims to establish the foundations for the use of VCTE in children and adolescents in order to achieve early diagnosis of NAFLD. Moreover, it will serve to understand in further detail the disease and to identify the risk groups of children and adolescents who may be at risk of developing it. Ultimately, this will help determine to which subgroups of the population we need to target resources for prevention and early detection of this entity, as well as possible intervention for its treatment.

TRIAL REGISTRATION

The LiverKids study is registered on Clinicaltrials.gov (NCT05526274).

Clinical Performance of Transient Elastography With Comparison to Quantitative Magnetic Resonance Imaging, Ultrasound, and Biopsy in Children and Adolescents With Known or Suspected Fatty Liver Disease

Background: Performance of vibration-controlled transient elastography (VCTE) is inadequately validated in pediatric nonalcoholic fatty liver disease (NAFLD). We aimed to assess the technical performance of VCTE in pediatric NAFLD and define the agreement between VCTE and reference standards of imaging and/or biopsy. Methods: This prospective study recruited participants with known or suspected NAFLD who underwent a research VCTE examination (FibroScan Mini 430). Ten valid VCTE liver stiffness measurements (kPa) and controlled attenuation parameter (CAP) (dB/m) measurements were obtained for each participant. Available clinically acquired MR elastography and magnetic resonance imaging proton density fat fraction (PDFF), liver ultrasound shear wave elastography, and biopsy served as references standards. Results: Eighty-four consecutive participants were included (55 males, mean age 15.0 ± 3.5 years, mean BMI 36.6 ± 9.4 kg/m2). VCTE examinations were complete in 80/83 participants. 37/83 participants were examined with an XL probe. There was no significant correlation between CAP and PDFF [n = 16; r = 0.17 (95% confidence interval [CI]: -0.34 to 0.61), p = 0.5] or between VCTE liver stiffness and MR elastography stiffness [n = 27; r = 0.31 (95% CI: -0.07 to 0.62), p = 0.10]. For prediction of any fibrosis stage ≥1 on biopsy (n = 9/15 participants), VCTE median liver stiffness >5.1 kPA had an area under receiver operating characteristic curve of 0.52 (95% CI: 0.26-0.78) with a sensitivity of 88.9% and specificity of 16.6% (p > 0.99). Conclusions: Complete VCTE examinations could be obtained in most pediatric patients with NAFLD. Neither VCTE liver stiffness nor CAP correlated well with measures of liver fat or stiffness by established imaging modalities and biopsy.

Prospective study of quantitative liver MRI in cystic fibrosis: feasibility and comparison to PUSH cohort ultrasound

BACKGROUND

Pediatric radiologists can identify a liver ultrasound (US) pattern predictive of progression to advanced liver disease. However, reliably discriminating these US patterns remains difficult. Quantitative magnetic resonance imaging (MRI) may provide an objective measure of liver disease in cystic fibrosis (CF).

OBJECTIVE

The purpose of this study was to determine if quantitative MRI, including MR elastography, is feasible in children with CF and to determine how quantitative MRI-derived metrics compared to a research US.

MATERIALS AND METHODS

A prospective, multi-institutional trial was performed evaluating CF participants who underwent a standardized MRI. At central review, liver stiffness, fat fraction, liver volume, and spleen volume were obtained. Participants whose MRI was performed within 1 year of US were classified by US pattern as normal, homogeneous hyperechoic, heterogeneous, or nodular. Each MRI measure was compared among US grade groups using the Kruskal-Wallis test.

RESULTS

Ninety-three participants (51 females [54.8%]; mean 15.6 years [range 8.1-21.7 years]) underwent MRI. MR elastography was feasible in 87 participants (93.5%). Fifty-eight participants had an US within 1 year of MRI. In these participants, a nodular liver had significantly higher stiffness (P<0.01) than normal or homogeneous hyperechoic livers. Participants with a homogeneous hyperechoic liver had a higher fat fraction (P<0.005) than others.

CONCLUSION

MR elastography is feasible in children with CF. Participants with a nodular pattern had higher liver stiffness supporting the US determination of advanced liver disease. Participants with a homogeneous hyperechoic pattern had higher fat fractions supporting the diagnosis of steatosis.

Cancer Therapy-related Hepatic Injury in Children: Imaging Review from the Pediatric LI-RADS Working Group

The liver is the primary organ for the metabolism of many chemotherapeutic agents. Treatment-induced liver injury is common in children undergoing cancer therapy. Hepatic injury occurs due to various mechanisms, including biochemical cytotoxicity, hepatic vascular injury, radiation-induced cytotoxicity, and direct hepatic injury through minimally invasive and invasive surgical treatments. Treatment-induced liver injury can be seen contemporaneous with therapy and months to years after therapy is complete. Patients can develop a combination of hepatic injuries manifesting during and after treatment. Acute toxic effects of cancer therapy in children include hepatitis, steatosis, steatohepatitis, cholestasis, hemosiderosis, and vascular injury. Longer-term effects of cancer therapy include hepatic fibrosis, chronic liver failure, and development of focal liver lesions. Quantitative imaging techniques can provide useful metrics for disease diagnosis and monitoring, especially in treatment-related diffuse liver injury such as hepatic steatosis and steatohepatitis, hepatic iron deposition, and hepatic fibrosis. Focal liver lesions, including those developing as a result of treatment-related vascular injury such as focal nodular hyperplasia-like lesions and hepatic perfusion anomalies, as well as hepatic infections occurring as a consequence of immune suppression, can be anxiety provoking and confused with recurrent malignancy or hepatic metastases, although there often are imaging features that help elucidate the correct diagnosis. Radiologic evaluation, in conjunction with clinical and biochemical screening, is integral to diagnosing and monitoring hepatic complications of cancer therapy in pediatric patients during therapy and after therapy completion for long-term surveillance. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material See the invited commentary by Ferraciolli and Gee in this issue.

Pediatric Obesity: Complications and Current Day Management

Obesity affects approximately 1 in 5 youth globally and increases the risk of complications during adolescence and young adulthood, including type 2 diabetes, dyslipidemia, hypertension, non-alcoholic fatty liver disease, obstructive sleep apnea, and polycystic ovary syndrome. Children and adolescents with obesity frequently experience weight stigma and have an impaired quality of life, which may exacerbate weight gain. Pediatric obesity is typically defined using sex-, age-, and population-specific body mass index percentiles. Once identified, pediatric obesity should always be managed with lifestyle modification. However, adolescents with obesity may also benefit from anti-obesity medications (AOM), several of which have been approved for use in adolescents by the US Food and Drug Administration, including liraglutide, phentermine/topiramate, and semaglutide. For children with specific, rare monogenic obesity disorders, setmelanotide is available and may lead to significant weight loss. Metabolic and bariatric surgery may be used for the management of severe obesity in youth; though highly effective, it is limited to specialized centers and has had relatively low pediatric uptake. In this narrative review using pediatric-focused data from original research, reviews, clinical practice guidelines, governmental agencies, and pharmaceutical companies, we review obesity-related metabolic complications in youth and management strategies, including AOM and bariatric surgery.

Liver transient elastography values in healthy South African children

BACKGROUND

Transient elastography (TE) is a rapid noninvasive ultrasound-based technology that measures liver stiffness as a surrogate for liver fibrosis and controlled attenuation parameter (CAP) as a measure of liver steatosis. However, normal ranges in children are not well defined in all populations. The aim of this study was to determine transient elastography values in healthy South African children.

METHODS

From April 2019 to December 2021, children were recruited from the HIV negative control group of a cohort study. Only children neither overweight nor obese, without evidence of liver disease, no medical condition or medication associated with hepatic steatosis or fibrosis and normal metabolic profile were included in this cross-sectional analysis. Clinical data, anthropometry and blood samples were collected on the same day as transient elastography with controlled attenuation parameter was performed.

RESULTS

104 children (median age 12.8 years [IQR 11.4-14.8, range 7.9-17.7 years]; 59 [57%] boys) were included. Liver stiffness was positively correlated with age (Pearson's r = 0.39, p < 0.001). Median liver stiffness in boys (5.2 kPa [5th to 95th percentiles 3.6 to 6.8 kPa]) was greater than in girls (4.6 kPa [5th to 95th percentiles 3.6 to 6.1 kPa; p = 0.004]), but there was no difference by ethnicity. Median CAP was 179dB/m (5th to 95th percentiles 158 to 233dB/m). There was a positive correlation between CAP and body mass index (BMI) z-score, but no difference by age, sex, ethnicity or pubertal status.

CONCLUSION

Liver stiffness values increase with age and are higher in healthy South African boys than girls, whereas CAP values vary with BMI, but not with age or sex.

Ultrasound attenuation imaging: a reproducible alternative for the noninvasive quantitative assessment of hepatic steatosis in children

BACKGROUND

Pediatric hepatic steatosis is a global public health concern, as an increasing number of children are affected by this condition. Liver biopsy is the gold standard diagnostic method; however, this procedure is invasive. Magnetic resonance imaging (MRI)-derived proton density fat fraction has been accepted as an alternative to biopsy. However, this method is limited by cost and availability. Ultrasound (US) attenuation imaging is an upcoming tool for noninvasive quantitative assessment of hepatic steatosis in children. A limited number of publications have focused on US attenuation imaging and the stages of hepatic steatosis in children.

OBJECTIVE

To analyze the usefulness of ultrasound attenuation imaging for the diagnosis and quantification of hepatic steatosis in children.

MATERIAL AND METHODS

Between July and November 2021, 174 patients were included and divided into two groups: group 1, patients with risk factors for steatosis (n = 147), and group 2, patients without risk factors for steatosis (n = 27). In all cases, age, sex, weight, body mass index (BMI), and BMI percentile were determined. B-mode US (two observers) and US attenuation imaging with attenuation coefficient acquisition (two independent sessions, two different observers) were performed in both groups. Steatosis was classified into four grades (0: absent, 1: mild, 2: moderate and 3: severe) using B-mode US. Attenuation coefficient acquisition was correlated with steatosis score according to Spearman's correlation. Attenuation coefficient acquisition measurements' interobserver agreement was assessed using intraclass correlation coefficients (ICC).

RESULTS

All attenuation coefficient acquisition measurements were satisfactory without technical failures. The median values for group 1 for the first session were 0.64 (0.57-0.69) dB/cm/MHz and 0.64 (0.60-0.70) dB/cm/MHz for the second session. The median values for group 2 for the first session were 0.54 (0.51-0.56) dB/cm/MHz and 0.54 (0.51-0.56) dB/cm/MHz for the second. The average attenuation coefficient acquisition was 0.65 (0.59-0.69) dB/cm/MHz for group 1 and 0.54 (0.52-0.56) dB/cm/MHz for group 2. There was excellent interobserver agreement at 0.94 (95% CI 0.92-0.96). There was substantial agreement between both observers (κ = 0.77, with a P < 0.001). There was a positive correlation between ultrasound attenuation imaging and B-mode scores for both observers (r = 0.87, P < 0.001 for observer 1; r = 0.86, P < 0.001 for observer 2). Attenuation coefficient acquisition median values were significantly different for each steatosis grade (P < 0.001). In the assessment of steatosis by B-mode US, the agreement between the two observers was moderate (κ = 0.49 and κ = 0.55, respectively, with a P < 0.001 in both cases).

CONCLUSION

US attenuation imaging is a promising tool for the diagnosis and follow-up of pediatric steatosis, which provides a more repeatable form of classification, especially at low levels of steatosis detectable in B-mode US.

Obesity, but not glycemic control, predicts liver steatosis in children with type 1 diabetes

OBJECTIVE

Nonalcoholic fatty liver disease (NAFLD), the most common liver disease in children, is strongly associated with obesity and insulin resistance. Although type 1 diabetes (T1D) is characterized by insulin deficiency, increasing obesity rates among children with T1D is a major risk factor for NAFLD in this patient population. Predisposing factors for NAFLD in children with T1D are not known.

STUDY DESIGN

This is a cross-sectional study comparing children with T1D across the range of body mass index (BMI) to the BMI-matched obese group without T1D. Hepatic steatosis was semi-quantitatively measured via the vibration-controlled transient elastogram (VCTE) method. Linear regression analysis was performed to assess the relationship between controlled-attenuated parameter (CAP) scores and clinical parameters. Receiver-operator curve (ROC) analysis was used to evaluate the diagnostic performance of several clinical parameters against NAFLD status determined via CAP.

RESULTS

Two-thirds of subjects with obesity had CAP scores suggestive of NAFLD, while 16 % (n = 6) of T1D patients without obesity had elevated CAP. Obese subjects were different from non-obese subjects in many laboratory and clinical characteristics, regardless of T1D status. CAP score was significantly associated with BMI, HDL-Cholesterol (HDL-c), and HbA1c in all subjects as well as the T1D-only subgroup. Among subjects with obesity only, age, HDL-cand ALT were the most significant predictors. Diagnostic performance of BMI, HDL-c, and BMI/HDL ratio were in the good to the excellent range for predicting NAFLD among all subjects, while performance varied for T1D-only or obesity-only groups.

CONCLUSION

The clinical and imaging findings of children with T1D and obesity are comparable to non-diabetic children with a similar degree of obesity. Obesity is the major risk factor for NAFLD in pediatric T1D. BMI, HDL-c, and BMI/HDL ratio may be helpful markers to determine further workup for NAFLD in children with T1D, particularly those with obesity.

Intensive Lifestyle Management Improves Steatosis and Fibrosis in Pediatric Nonalcoholic Fatty Liver Disease

BACKGROUND & AIMS

Childhood obesity, with associated comorbidities such as nonalcoholic fatty liver disease (NAFLD), is an increasing global health problem. Although lifestyle management is the mainstay of treatment, its efficacy on liver fibrosis has not yet been established.

METHODS

Children and adolescents admitted for severe obesity at a tertiary center (Zeepreventorium, De Haan, Belgium) were enrolled in this prospective study. Intensive lifestyle therapy encompassed caloric restriction, physical activity, education on a healthy lifestyle, and psychosocial support. At baseline, 6 months, and 12 months, liver ultrasound and transient elastography with controlled attenuation parameter were performed to assess liver steatosis and fibrosis.

RESULTS

A total of 204 patients (median age, 14.0 y; body mass index Z-score, +2.8) were evaluated at admission. NAFLD on ultrasound was present in 71.1%, whereas 68.6% had controlled attenuation parameter values of 248 dB/m or greater. A total of 32.8% of patients had at least F2 fibrosis, including 10.3% with transient elastography of 9 kPa or greater. After 6 months, the median body weight loss was 16.0% in the 167 patients evaluated. Fibrosis improved in 75.0% (P < .001). Baseline severity of liver fibrosis and steatosis were predictors of fibrosis resolution. Seventy-nine patients had reached the 1-year time point. The improvements were sustained because fibrosis regressed at least 1 stage in all patients with baseline fibrosis. Fasting serum alanine aminotransferase and homeostasis model assessment of insulin resistance decreased significantly over the 1-year period (P < .001).

CONCLUSIONS

NAFLD and associated fibrosis are highly prevalent in children and adolescents with severe obesity. An intensive multidisciplinary lifestyle management program that causes significant weight loss not only improves liver steatosis, but also fibrosis.

Improving the accuracy of fatty liver index to reflect liver fat content with predictive regression modelling

Background

The fatty liver index (FLI) is frequently used as a non-invasive clinical marker for research, prognostic and diagnostic purposes. It is also used to stratify individuals with hepatic steatosis such as non-alcoholic fatty liver disease (NAFLD), and to detect the presence of type 2 diabetes or cardiovascular disease. The FLI is calculated using a combination of anthropometric and blood biochemical variables; however, it reportedly excludes 8.5-16.7% of individuals with NAFLD. Moreover, the FLI cannot quantitatively predict liver fat, which might otherwise render an improved diagnosis and assessment of fatty liver, particularly in longitudinal studies. We propose FLI+ using predictive regression modelling, an improved index reflecting liver fat content that integrates 12 routinely-measured variables, including the original FLI.

Methods and findings

We evaluated FLI+ on a dataset from the UK Biobank containing 28,796 individual estimates of proton density fat fraction derived from magnetic resonance imaging across normal to severe levels and interpolated to align with the original FLI range. The results obtained for FLI+ outperform the original FLI by delivering a lower mean absolute error by approximately 47%, a lower standard deviation by approximately 20%, and an increased adjusted R² statistic by approximately 49%, reflecting a more accurate representation of liver fat content.

Conclusions

Our proposed model predicting FLI+ has the potential to improve diagnosis and provide a more accurate stratification than FLI between absent, mild, moderate and severe levels of hepatic steatosis.

Meta-analysis: global prevalence, trend and forecasting of non-alcoholic fatty liver disease in children and adolescents, 2000-2021

BACKGROUND

NAFLD is increasing in children.

AIMS

To determine the recent trend and forecast the future global prevalence of paediatric NAFLD METHODS: We searched PubMed, Embase, Web of Science and Cochrane library databases from inception to 1 May 2021 for studies of children and adolescents (≤21 years) with NAFLD. Obesity was defined with weight at ≥95th percentile and overweight as 85th to <95th percentile as per the Center for Disease Control BMI-for-age percentile cut-offs.

RESULTS

From 3350 titles and abstracts, we included 74 studies (276,091 participants) from 20 countries/regions. We included 14 studies in the general NAFLD prevalence analysis, yielding an overall prevalence of 7.40% (95% CI: 4.17-12.81) regardless of the diagnostic method, and 8.77% (95% CI: 3.86-18.72) by ultrasound. Among continents with more than one study, the prevalence of NAFLD was 8.53% (95% CI: 5.71-12.55) for North America, 7.01% (95% CI: 3.51-13.53) for Asia, and 1.65% (95% CI: 0.97-2.80) for Europe. NAFLD prevalence regardless of the diagnostic method was 52.49% (95% CI: 46.23-58.68, 9159 participants) and 39.17% (95% CI: 30.65-48.42, 5371 participants) among obese and overweight/obese participants, respectively. For the general population, trend analysis from 2000 to 2017 indicates an increasing global prevalence of paediatric NAFLD from 4.62% to 9.02% at a yearly increase of 0.26%, whereas forecast analysis predicts a prevalence of 30.7% by 2040.

CONCLUSION

The prevalence of paediatric NAFLD varies by region and is 52.49% overall among the obese population and 7.40% in the general population. It is predicted to reach 30.7% by 2040.

Feasibility of Ultrasound Attenuation Imaging for Assessing Pediatric Hepatic Steatosis

We investigated the feasibility of ultrasound attenuation imaging (ATI) for assessing pediatric hepatic steatosis. A total of 111 children and adolescents who underwent liver ultrasonography with ATI for suspected hepatic steatosis were included. Participants were classified into the normal, mild, or moderate−severe fatty liver group according to grayscale US findings. Associations between clinical factors, magnetic resonance imaging proton density fat fraction, steatosis stage and ATI values were evaluated. To determine the cutoff values of ATI for staging hepatic steatosis, areas under the curve (AUCs) were analyzed. Factors that could cause measurement failure with ATI were assessed. Of 111 participants, 88 had successful measurement results. Median ATI values were significantly increased according to steatosis stage (p < 0.001). Body mass index (BMI) was a significant factor for increased ATI values (p = 0.047). To differentiate fatty liver from normal liver, a cutoff value of 0.59 dB/cm/MHz could be used with an AUC value of 0.853. To differentiate moderate to severe fatty liver from mild fatty liver, a cutoff value of 0.69 dB/cm/MHz could be used with an AUC value up to 0.91. ATI can be used in children as an effective ultrasonography technique for quantifying and staging pediatric hepatic steatosis.

Attenuation Coefficient Measurement Using a High-Frequency (2-9 MHz) Convex Transducer for Children Including Fatty Liver

We evaluated the measurement feasibility and diagnostic ability of an ultrasound-guided attenuation parameter (UGAP) using a high-frequency convex transducer in children. This retrospective study included all consecutive children who underwent abdomen ultrasonography from July to December 2020. Attenuation coefficients (ACs) of the liver were measured using both 1- to 6-MHz (AC1-6) and 2- to 9-MHz (AC2-9) probes of the LOGIQ E10 system (GE Healthcare). t-Tests and Pearson's or partial correlation analyses were performed, and AC cutoff values for diagnosing fatty liver were obtained from receiver operating characteristic curve analyses. Finally, 118 patients (M:F = 83:35, mean age: 10.2 ± 4.1 y) were evaluated, and the measurement success rate was 98.3% (116/118) for AC2-9. AC1-6 was available in children with a liver depth greater than 9 cm. The ratio of interquartile range to median of the AC2-9 was lower than that of the AC1-6 (4.3 vs. 8.5, p < 0.001). In the normal group (n = 41), the AC2-9 values were not associated with age, sex or body mass index. For the evaluation of steatosis, the AC2-9 values exhibited a positive correlation with the MR fat fraction (coefficient = 0.498, p < 0.001). The cutoff value of 0.699 dB/cm/MHz had 90.2% sensitivity and 100% specificity for diagnosing fatty liver. In conclusion, measurements of ACs using a high-frequency convex transducer are feasible even in small children, with lower measurement variability. The AC2-9 values also had good diagnostic performance for pediatric fatty liver.

Controlled attenuation parameter in the diagnosis of different liver steatosis groups in children with obesity

OBJECTIVE

To investigate the utility of the controlled attenuation parameter (CAP), as measured by a liver elastography technique, in predicting varying degrees of liver steatosis in children with obesity.

METHODS

Children with obesity attending the pediatric obesity clinic at the Affiliated Hospital of Hangzhou Normal University from July 2020 to May 2021 were retrospectively analysed. The 71 subjects were divided into four groups according to the degree of liver steatosis obtained by magnetic resonance imaging-proton density fat fraction (MRI-PDFF). The gender, age, CAP, LSM, ALT, AST, BMI, uric acid, fasting blood glucose, total cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein, insulin, and blood 25-hydroxyvitamin D levels of the four groups were compared, and the differences were analysed. Clinical data with significant differences were included in the logistic regression analysis. The receiver operating characteristic (ROC) curve for the CAP for the 71 subjects with different degrees of liver steatosis was plotted to evaluate the diagnostic value.

RESULTS

The 71 children were divided into groups according to the degree of hepatic steatosis obtained by MRI-PDFF, and the clinical data for each group were compared. It was found that there was statistical significance for CAP, ALT, and AST in cases of moderate and severe hepatic steatosis (p < 0.05). Logistic regression analysis was conducted between CAP, ALT, AST, and moderate to severe hepatic steatosis in children with obesity, and it was found that CAP was a factor related to moderate to severe hepatic steatosis in children with obesity. The ROC curve indicated that CAP has diagnostic value for NAFLD in children with obesity.

CONCLUSION

There is diagnostic value in the use of CAP for hepatic steatosis in children with obesity, and there is greater diagnostic value in the use of CAP for children with moderate to severe hepatic steatosis.

Accuracy of attenuation imaging in the assessment of pediatric hepatic steatosis: correlation with the controlled attenuation parameter

PURPOSE

This study evaluated the accuracy of attenuation imaging (ATI) for the assessment of hepatic steatosis in pediatric patients, in comparison with the FibroScan vibration-controlled transient elastography controlled attenuation parameter (CAP).

METHODS

Consecutive pediatric patients referred for evaluation of obesity who underwent both ATI and FibroScan between February 2020 and September 2021 were included. The correlation between attenuation coefficient (AC) and CAP values was assessed using the Spearman test. The AC cutoff value for discriminating hepatic steatosis corresponding to a CAP value of 241 dB/m was calculated. Multivariable linear regression analysis was performed to estimate the strength of the association between AC and CAP. The diagnostic accuracy of AC cutoffs was estimated using the imperfect gold-standard methodology based on a two-level Bayesian latent class model.

RESULTS

Seventy patients (median age, 12.5 years; interquartile range, 11.0 to 14.0 years; male:female, 58:12) were included. AC and CAP showed a moderate-to-good correlation (ρ =0.646, P<0.001). Multivariable regression analysis affirmed the significant association between AC and CAP (P<0.001). The correlation was not evident in patients with a body mass index ≥30 kg/m2 (ρ=-0.202, P=0.551). Linear regression revealed that an AC cutoff of 0.66 dB/cm/MHz corresponded to a CAP of 241 dB/m (sensitivity, 0.93; 95% confidence interval [CI], 0.85 to 0.98 and specificity, 0.87; 95% CI, 0.56 to 1.00).

CONCLUSION

ATI showed an acceptable correlation with CAP values in a pediatric population, especially in patients with a body mass index <30 kg/m2. An AC cutoff of 0.66 dB/cm/MHz, corresponding to a CAP of 241 dB/m, can accurately diagnose hepatic steatosis.

Usefulness of Controlled Attenuation Parameter for Identification and Grading of Nonalcoholic Fatty Liver Disease in Adolescents with Obesity

OBJECTIVE

To identify controlled attenuation parameter (CAP) based cutoffs for diagnosing and grading hepatic steatosis in adolescents with overweight/obesity, using magnetic resonance imaging-proton density fat fraction (MRI-PDFF) as the reference method.

METHODS

Adolescents with overweight/obesity were included. Fasting glucose, insulin, aspartate aminotransferase, and alanine aminotransferase were estimated. Hepatic steatosis (S) was assessed by MRI-PDFF, and graded as S0, S1, S2, and S3 with fat fraction cutoffs of < 6.0%, ≥ 6.0% to < 17.5%, ≥ 17.5% to < 23.3%, and ≥ 23.3%, respectively. CAP and liver stiffness measure (LSM) were assessed using FibroScan. Receiver operating characteristic (ROC) curves were used to estimate the CAP scores predicting various grades of hepatic steatosis.

RESULTS

A total of 108 adolescents aged 12.4 ± 1.9 y, with mean BMI of 26.7 ± 4.9 kg/m² were included. S0, S1, S2, and S3 steatosis by MRI-PDFF was identified in 15, 70, 13, and 10 adolescents, respectively. A moderate positive correlation was observed between CAP score and MRI-estimated hepatic fat (r = 0.528, p < 0.001). The optimal CAP cutoffs for identifying ≥ S1, ≥ S2, and S3 steatosis were 271 [area under ROC (AUROC) 0.745 (0.630-0.859)], 296 [AUROC 0.820 (0.728-0.911)], and 309 dB/m [AUROC 0.836 (0.729-0.944)], respectively.

CONCLUSION

CAP score had a good discriminative ability to diagnose fatty liver in adolescents with overweight or obesity.

Non-invasive assessment of fibrosis and steatosis in pediatric non-alcoholic fatty liver disease

BACKGROUND AND AIMS

Non-Alcoholic Fatty Liver Disease (NAFLD) has become one of the most common causes of chronic liver disease in the pediatric population. Recent advances have been made in developing non-invasive measures for NAFLD assessment. This review presents an analysis of these latest developments and also proposes an algorithm for screening pediatric patients at risk for NAFLD.

METHODS

A systematic literature search on PUBMED and EMBASE was conducted. Guidelines for clinical care of pediatric NAFLD were also reviewed.

RESULTS

In imaging tests, transient elastography (TE) combined with controlled attenuation parameter (CAP) is a promising, relatively low-cost method offering an intermediate level of accuracy on accessing patient's fibrosis and steatosis in a singular package. Liver biopsy remains the gold standard for diagnosis and/or evaluation of NAFLD, but with our proposed algorithm on utilizing non-invasive testing, the number of liver biopsies required could decrease. The current evidence supports the implementation of TE and CAP in an evaluation algorithm for pediatric NAFLD.

CONCLUSIONS

Current data support the use of TE and CAP as a first-line tool in the diagnosis and evaluation of adolescent NAFLD, to better stratify high-risk patients and cut down on the number of liver biopsies needed.

Metabolic Fatty Liver Disease in Children: A Growing Public Health Problem

Metabolic-associated fatty liver disease (MAFLD), previously called nonalcoholic fatty liver diseases (NAFLD), is one of the most important causes of chronic liver disease worldwide and will likely become the leading cause of end-stage liver disease in the decades ahead. MAFLD covers a continuum of liver diseases from fatty liver to nonalcoholic steatohepatitis (NASH), liver fibrosis/cirrhosis and hepatocellular cancer. Importantly, the growing incidence of overweight and obesity in childhood, 4% in 1975 to 18% in 2016, with persisting obesity complications into adulthood, is likely to be harmful by increasing the incidence of severe MAFLD at an earlier age. Currently, MAFLD is the leading form of chronic liver disease in children and adolescents, with a global prevalence of 3 to 10%, pointing out that early diagnosis is therefore crucial. In this review, we highlight the current knowledge concerning the epidemiology, risk factors and potential pathogenic mechanisms, as well as diagnostic and therapeutic approaches, of pediatric MAFLD.

Recent advances in the epidemiology of nonalcoholic fatty liver disease in children

Children with obesity are at risk for numerous health problems, including nonalcoholic fatty liver disease (NAFLD). This review focuses on progress made in the epidemiology of NAFLD in children for the years 2015-2020. The estimated prevalence of NAFLD in children with obesity is 26%. The incidence of NAFLD in children has risen rapidly over the past decade. An understanding of the reasons for this rise is incomplete, but over the past 5 years, many studies have provided additional insight into the complexity of risk factors, diagnostic approaches, and associated comorbidities. Risk factors for NAFLD are wide-ranging, including perinatal factors involving both the mother and newborn, as well as environmental toxin exposure. Progress made in the noninvasive assessment will be critical to improving issues related to variability in approach to screening and diagnosis of NAFLD in children. The list of serious comorbidities observed in children with NAFLD continues to grow. Notably, for many of these conditions, such as diabetes and depression, the rates observed have exceeded the rates reported in children with obesity without NAFLD. Recent advancements reviewed show an increased awareness of this problem, while also calling attention to the need for additional research to guide successful efforts at prevention and treatment.

Quantification of Liver Fat Content with CT and MRI: State of the Art

Hepatic steatosis is defined as pathologically elevated liver fat content and has many underlying causes. Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, with an increasing prevalence among adults and children. Abnormal liver fat accumulation has serious consequences, including cirrhosis, liver failure, and hepatocellular carcinoma. In addition, hepatic steatosis is increasingly recognized as an independent risk factor for the metabolic syndrome, type 2 diabetes, and, most important, cardiovascular mortality. During the past 2 decades, noninvasive imaging-based methods for the evaluation of hepatic steatosis have been developed and disseminated. Chemical shift-encoded MRI is now established as the most accurate and precise method for liver fat quantification. CT is important for the detection and quantification of incidental steatosis and may play an increasingly prominent role in risk stratification, particularly with the emergence of CT-based screening and artificial intelligence. Quantitative imaging methods are increasingly used for diagnostic work-up and management of steatosis, including treatment monitoring. The purpose of this state-of-the-art review is to provide an overview of recent progress and current state of the art for liver fat quantification using CT and MRI, as well as important practical considerations related to clinical implementation.

Longitudinal associations of total and trunk fat in childhood and adolescence and risk of hepatic steatosis at 24 years

BACKGROUND

The importance of body fat distribution in the development of nonalcoholic fatty liver disease (NAFLD) is unclear.

OBJECTIVE

To examine whether total and truncal fat deposition patterns in childhood/adolescence are associated with NAFLD risk at 24 years.

METHODS

Data were from 1657 participants in the Avon Longitudinal Study of Parents and Children. Transient elastography was used to assess hepatic steatosis (low/moderate/severe) at 24 years and dual-energy X-ray absorptiometry was used to assess total body fat percent (TBF%) and trunk fat percent (TrF%) at 9, 13, 15, 17, and/or 24 years. Linear mixed models were constructed with quadratic age to examine trajectories of TBF% and TrF% by steatosis at 24 years, adjusting for confounders.

RESULTS

In both sexes, TBF% trajectories from 9 to 24 years followed a similar pattern based on steatosis group (P = .83 for boys and P = .14 for girls for age² *steatosis fixed effect). However, at all ages TBF% was higher for moderate/severe vs low steatosis at 24 years (P < .05). In contrast, TrF% trajectories diverged based on steatosis group (P = .001 for boys and P = .0002 for girls for age² *steatosis fixed effect), such that, in both sexes, participants with moderate/severe steatosis at 24 yrs exhibited less decline in TrF% from adolescence to adulthood compared to participants with low steatosis at 24 yrs. Similar to TBF%, TrF% was higher at nearly all ages for moderate/severe vs low steatosis. Results were similar after adjusting for BMI category at each age, except in boys some differences for TrF% were attenuated.

CONCLUSIONS

These findings suggest that sex-specific body fat distribution patterns in childhood/adolescence may help to identify those at risk of developing NAFLD in adulthood.

Diagnosis and Staging of Pediatric Non-Alcoholic Fatty Liver Disease: Is Classical Ultrasound the Answer?

The increased prevalence of non-alcoholic fatty liver disease (NAFLD) requires special attention in pediatric patients, as it manifests in them in a more severe and progressive way compared to adults. The implementation of the appropriate therapeutic interventions is determinant of the attempts to treat it. For that purpose, early diagnosis and staging of the disease is essential. The purpose of this review was to find and reveal the most appropriate diagnostic strategies and tools for diagnosis and staging of pediatric NAFLD/NASH based on their accuracy, safety and effectiveness. The methodology followed was that of the literature review. Particular emphasis was put on the recent bibliography. A comparative study of published articles about the diagnosis and management of pediatric NAFLD/NASH was also performed. In terms of diagnosis, the findings converged on the use of classical ultrasound. Ultrasound presented average sensitivity and specificity for diagnosing the disease in children, while in the adult population, sensitivity and specificity were significantly higher. Proton density fat fraction magnetic resonance imaging has been increasingly used for the diagnosis of steatosis in pediatric patients. Elastography is an effective tool for staging liver fibrosis and discriminating NASH from NAFLD in children. Even though liver biopsy is the gold standard, especially for NASH, it should be avoided for pediatric patients. Biochemical tests are less specific and less sensitive for the diagnosis of NAFLD, and some of them are of high cost. It seems that diagnostic imaging should be a first-line tool for the staging and monitoring pediatric NAFLD/NASH in order for appropriate interventions to be implanted in a timely way.

Comparison between magnetic resonance and ultrasound-derived indicators of hepatic steatosis in a pooled NAFLD cohort

BACKGROUND & AIMS

MRI-based proton density fat fraction (PDFF) and the ultrasound-derived controlled attenuation parameter (CAP) are non-invasive techniques for quantifying liver fat, which can be used to assess steatosis in patients with non-alcoholic fatty liver disease (NAFLD). This study compared both of these techniques to histopathological graded steatosis for the assessment of fat levels in a large pooled NAFLD cohort.

METHODS

This retrospective study pooled N = 581 participants from two suspected NAFLD cohorts (mean age (SD) 56 (12.7), 60% females). Steatosis was graded according to NASH-CRN criteria. Liver fat was measured non-invasively using PDFF (with Liver MultiScan's Iterative Decomposition of water and fat with Echo Asymmetry and Least-squares estimation method, LMS-IDEAL, Perspectum, Oxford) and CAP (FibroScan, Echosens, France), and their diagnostic performances were compared.

RESULTS

LMS-IDEAL and CAP detected steatosis grade ≥ 1 with AUROCs of 1.00 (95% CI, 0.99-1.0) and 0.95 (95% CI, 0.91-0.99), respectively. LMS-IDEAL was superior to CAP for detecting steatosis grade ≥ 2 with AUROCs of 0.77 (95% CI, 0.73-0.82] and 0.60 (95% CI, 0.55-0.65), respectively. Similarly, LMS-IDEAL outperformed CAP for detecting steatosis grade ≥ 3 with AUROCs of 0.81 (95% CI, 0.76-0.87) and 0.63 (95% CI, 0.56-0.70), respectively.

CONCLUSION

LMS-IDEAL was able to diagnose individuals accurately across the spectrum of histological steatosis grades. CAP performed well in identifying individuals with lower levels of fat (steatosis grade ≥1); however, its diagnostic performance was inferior to LMS-IDEAL for higher levels of fat (steatosis grades ≥2 and ≥3).

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03551522); https://clinicaltrials.gov/ct2/show/NCT03551522. UMIN Clinical Trials Registry (UMIN000026145); https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000026145.

Performance Characteristics, Intra- and Inter-operator Agreement of Transient Elastography in Pediatric Nonalcoholic Fatty Liver Disease

BACKGROUND AND AIMS

Transient elastography (TE) is a valuable tool in assessment of hepatic steatosis and fibrosis using liver stiffness measurement (LSM) and controlled attenuation parameter (CAP), respectively. Although widely used in adults, little is known about performance characteristics and reproducibility of TE (using Fibroscan device) in evaluation of pediatric nonalcoholic fatty liver disease (NAFLD).

METHODS

We prospectively recruited children with NAFLD. Three consecutive Fibroscan examinations were performed during the same visit-twice by a single expert operator and once by a different novice operator. Intra and inter-operator agreement was calculated using concordance correlation coefficient (CCC). Failure was defined as inability to obtain 10 valid measurements and examination was considered unreliable if LSM interquartile range/median was greater 30%.

RESULTS

Fifty-one children (34 boys; median age 15 years) were recruited. Failure rates for expert and novice operator were 10% (5/51) and 12% (6/51) while unreliable readings were obtained in 2% (1/46) and 4% (2/45) of patients, respectively. Patients with failed/unreliable measurements were significantly more obese (median BMI 46.2 vs 33.1 kg/m2, P = 0.002) compared with those with reliable measurements. The intra-operator agreement was almost perfect for LSM and substantial for CAP values (CCC = 0.85 and 0.73, respectively). Inter-operator agreement was substantial for LSM and moderate for CAP values (CCC = 0.76 and 0.58, respectively). The inter-operator agreement in LSM did not vary significantly over time but showed an inverse correlation with BMI and CAP.

CONCLUSION

Our study demonstrated that use of TE in assessment of hepatic fibrosis and steatosis in children with NAFLD is highly reliable with low failure rate and highly reproducible with high intra- and inter-operator reproducibility.

Accuracy of controlled attenuation parameter compared with ultrasound for detecting hepatic steatosis in children with severe obesity

OBJECTIVES

To determine the diagnostic accuracy of controlled attenuation parameter (CAP) on FibroScan® in detecting and grading steatosis in a screening setting and perform a head-to-head comparison with conventional B-mode ultrasound.

METHODS

Sixty children with severe obesity (median BMI z-score 3.37; median age 13.7 years) were evaluated. All underwent CAP and US using a standardized scoring system. Magnetic resonance spectroscopy proton density fat fraction (MRS-PDFF) was used as a reference standard.

RESULTS

Steatosis was present in 36/60 (60%) children. The areas under the ROC (AUROC) of CAP for the detection of grade ≥ S1, ≥ S2, and ≥ S3 steatosis were 0.80 (95% CI: 0.67-0.89), 0.77 (95% CI: 0.65-0.87), and 0.79 (95% CI: 0.66-0.88), respectively. The AUROC of US for the detection of grade ≥ S1 steatosis was 0.68 (95% CI: 0.55-0.80) and not significantly different from that of CAP (p = 0.09). For detecting ≥ S1 steatosis, using the optimal cutoffs, CAP (277 dB/m) and US (US steatosis score ≥ 2) had a sensitivity of 75% and 61% and a specificity of 75% and 71%, respectively. When using echogenicity of liver parenchyma as only the scoring item, US had a sensitivity of 70% and specificity of 46% to detect ≥ S1 steatosis. The difference in specificity of CAP and US when using only echogenicity of liver parenchyma of 29% was significant (p = 0.04).

CONCLUSION

The overall performance of CAP is not significantly better than that of US in detecting steatosis in children with obesity, provided that the standardized scoring of US features is applied. When US is based on liver echogenicity only, CAP outperforms US in screening for any steatosis (≥ S1).

KEY POINTS

• The areas under the ROC curves of CAP and ultrasound (US) for detecting grade ≥ S1 steatosis were 0.80 and 0.68, respectively, and were not significantly different (p = 0.09). • For detecting grade ≥ S1 steatosis in severely obese children, CAP had a sensitivity of 75% and a specificity of 75% at its optimal cutoff value of 277 dB/m. • For detecting grade ≥ S1 steatosis in clinical practice, both CAP and US can be used, provided that the standardized scoring of US images is used.

Quantitative assessment of liver steatosis using ultrasound controlled attenuation parameter (Echosens)

Controlled attenuation parameter (CAP) is the algorithm available on the FibroScan system (Echosens, France) for quantification of liver steatosis. It assesses the ultrasound beam attenuation, which is directly related to liver fat content. The inter-observer reproducibility of the technique is high, with a reported concordance correlation coefficient of 0.82. Specific quality criteria for CAP measurements are not clearly defined yet, and there are conflicting results in the literature. Using liver biopsy as the reference standard, several studies have assessed the CAP performance in grading liver steatosis, and have reported that values are not affected by liver fibrosis. The cutoff for detection of liver steatosis reported in the literature ranges from 222 decibels per meter (dB/m) in a cohort of patients with chronic hepatitis C to 294 dB/m in a meta-analysis of nonalcoholic fatty liver disease (NAFLD) patients. CAP has been used as a tool to noninvasively evaluate the prevalence of NAFLD in groups at risk or in the general population; however, it should be underscored that different CAP cutoffs for steatosis detection (S > 0) were used in different studies, and this limits the robustness of the findings. CAP, alone or combined with other noninvasive indices or biomarkers, has been proposed as a tool for assessing nonalcoholic steatohepatitis or as a noninvasive predictor of prognosis in patients with chronic liver disease. CAP is easy to perform and has become a point-of-care technique. However, there is a large overlap of values between consecutive grades of liver steatosis, and cutoffs are not clearly defined.

Magnetic Resonance Imaging-Proton Density Fat Fraction vs. Transient Elastography-Controlled Attenuation Parameter in Diagnosing Non-alcoholic Fatty Liver Disease in Children and Adolescents: A Meta-Analysis of Diagnostic Accuracy

Background and Aim: Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children and adolescents, and its prevalence increases with obesity. Magnetic resonance imaging (MRI) and transient elastography (TE) have been widely used to non-invasively evaluate NAFLD in adults. This study aimed to determine the efficacy and accuracy of MRI-proton density fat fraction (MRI-PDFF) and TE-controlled attenuation parameter (TE-CAP) in distinguishing hepatic steatosis in children and adolescents. Materials and Methods: In this meta-analysis, the PubMed, Cochrane Library, Embase, Medline, and Web of Science databases were searched for articles that reported studies on the accuracy of MRI-PDFF or TE-CAP in grading the steatosis in children and adolescents with NAFLD. This study compared the sensitivity, specificity, and hierarchical summary receiver operating characteristic curves (HSROCs) of MRI-PDFF and TE-CAP in distinguishing between steatosis grades S0 and S1-3. Results: A total of eight articles involving 874 children and adolescents with NAFLD were included in this study. The proportions of steatosis grades were 5 and 95% for S0 and S1-3, respectively. MRI-PDFF accurately diagnosed S1-3 steatosis, with a summary sensitivity of 0.95 (95% CI, 0.92-0.97), specificity of 0.92 (95% CI, 0.77-0.98), and HSROC of 0.96 (95% CI, 0.94-0.98). Likewise, TE-CAP accurately diagnosed S1-3 steatosis, with a summary sensitivity of 0.86 (95% CI, 0.70-0.94), specificity of 0.88 (95% CI, 0.71-0.96), and HSROC of 0.94 (95% CI, 0.91-0.95). Following a "positive" measurement (over the threshold value) for S1-3, the corresponding post-test probabilities of MRI-PDFF and TE-CAP for the presence of steatosis reached 92 and 88%, respectively, at the pretest probability of 50%. When the values were below the mentioned threshold values ("negative" results), the post-test probabilities of MRI-PDFF and TE-CAP became 5 and 13%, respectively. Conclusion: Both MRI-PDFF and TE-CAP are highly accurate non-invasive methods to grade the hepatic steatosis in children and adolescents with NAFLD. Furthermore, MRI-PDFF is significantly more accurate in assessing steatosis grade than TE-CAP. Systematic Review Registration: PROSPERO, identifier: CRD42021220422.

Detection of pediatric hepatic steatosis through ultrasound backscattering analysis

OBJECTIVES

Hepatic steatosis has become a considerable concern in the pediatric population. The objective of this study was to evaluate the feasibility of using ultrasound Nakagami imaging to produce a parametric image for analyzing the echo amplitude distribution to assess pediatric hepatic steatosis.

METHODS

A total of 68 pediatric participants were enrolled in healthy control (n = 26) and study groups (n = 42). Raw data from ultrasound imaging were acquired for each participant analysis using AmCAD-US, a software approved by the US Food and Drug Administration for ultrasound Nakagami imaging. The Nakagami parameters were compared with the hepatic steatosis index (HSI) and the steatosis grade (G0: HSI < 30; G1: 30 ≤ HSI < 36; G2: 36 ≤ HSI < 41.6; G3: 41.6 ≤ HSI < 43; G4: HSI ≥ 43) using correlation analysis, one-way analysis of variance (ANOVA), and receiver operating characteristic (ROC) curve analysis.

RESULTS

The Nakagami parameter increased from 0.53 ± 0.13 to 0.82 ± 0.05 with increasing severity of hepatic steatosis from G0 to G4 and were significantly different between the different grades of hepatic steatosis (p < .05). The areas under the ROC curves were 0.96, 0.92, 0.85, and 0.82 for diagnosing hepatic steatosis ≥ G1, ≥ G2, ≥ G3, and ≥ G4, respectively.

CONCLUSIONS

The Nakagami parameter value quantifies changes in the echo amplitude distribution of ultrasound backscattered signals caused by fatty infiltration, providing a novel, noninvasive, and effective data analysis technique to detect pediatric hepatic steatosis.

KEY POINTS

• Ultrasound Nakagami imaging enabled quantification of the echo amplitude distribution for tissue characterization. • The Nakagami parameter increased with the increasing severity of pediatric hepatic steatosis. • The Nakagami parameter demonstrated promising diagnostic performance in evaluating pediatric hepatic steatosis.

Perspectives on youth-onset nonalcoholic fatty liver disease

BACKGROUND

The prevalence and incidence of youth-onset nonalcoholic fatty liver disease (NAFLD) far exceeds other paediatric chronic liver diseases and represents a considerable public health issue globally.

METHODS

Here, we performed a narrative review of current knowledge regarding the epidemiology of paediatric NAFLD, selected concepts in pathogenesis, comorbidities, diagnosis, and management, and issues related to the transition to adulthood.

RESULTS

Paediatric NAFLD has become increasingly more prevalent, especially in certain subgroups, such as children with obesity and certain races/ethnicities. The pathophysiology of paediatric NAFLD is complex and multifactorial, driven by an interaction of environmental and genetic factors. Once developed, NAFLD in childhood is associated with type 2 diabetes, hypertension, increased cardiovascular disease risk, and end-stage liver disease. This predicts an increased burden of morbidity and mortality in adolescents and young adults. Early screening and diagnosis are therefore crucial, and the development of noninvasive biomarkers remains an active area of investigation. Currently, treatment strategies are focused on lifestyle changes, but there is also research interest in pharmacological and surgical options. In the transition from paediatric to adult care, there are several potential challenges/barriers to treatment and research is needed to understand how best to support patients during this time.

CONCLUSIONS

Our understanding of the epidemiology and pathophysiology of paediatric NAFLD has increased considerably over recent decades, but several critical knowledge gaps remain and must be addressed in order to better mitigate the short-term and long-term risks of youth-onset NAFLD.

Evaluation of the changes in hepatic apparent diffusion coefficient and hepatic fat fraction in healthy cats during body weight gain

OBJECTIVE

To determine the change in mean hepatic apparent diffusion coefficient (ADC) and hepatic fat fraction (HFF) during body weight gain in cats by use of MRI.

ANIMALS

12 purpose-bred adult neutered male cats.

PROCEDURES

The cats underwent general health and MRI examination at time 0 (before dietary intervention) and time 1 (after 40 weeks of being fed high-energy food ad libitum). Sequences included multiple-echo gradient-recalled echo MRI and diffusion-weighted MRI with 3 b values (0, 400, and 800 s/mm²). Variables (body weight and the HFF and ADC in selected regions of interest in the liver parenchyma) were compared between time points by Wilcoxon paired-sample tests. Relationships among variables were assessed with generalized mixed-effects models.

RESULTS

Median body weight was 4.5 and 6.5 kg, mean ± SD HFF was 3.39 ± 0.89% and 5.37 ± 1.92%, and mean ± SD hepatic ADC was 1.21 ± 0.08 × 10^-3 mm²/s and 1.01 ± 0.2 × 10^-3 mm²/s at times 0 and 1, respectively. Significant differences between time points were found for body weight, HFF, and ADC. The HFF was positively associated with body weight and ADC was negatively associated with HFF.

CONCLUSIONS AND CLINICAL RELEVANCE

Similar to findings in people, cats had decreasing hepatic ADC as HFF increased. Protons associated with fat tissue in the liver may reduce diffusivity, resulting in a lower ADC than in liver with lower HFF. Longer studies and evaluation of cats with different nutritional states are necessary to further investigate these findings.

Effects of obesity reduction on transient elastography-based parameters in pediatric non-alcoholic fatty liver disease

AIM

To clarify the effects of obesity reduction on non-alcoholic fatty liver disease (NAFLD) in obese children.

METHODS

Twenty-six obese pediatric NAFLD patients (median age, 13.0 years; range, 6.4-16.6 years), who underwent obesity management supported by regular hospital visits and/or hospital admission, were studied to explore how reductions in weight and body mass index (BMI) percentile affected two transient elastography-based parameters: controlled attenuation parameter (CAP) and liver stiffness (LS), which reflect the degree of hepatic fat deposition and liver fibrosis, respectively.

RESULTS

Univariate analysis revealed that CAP reduction was correlated positively with baseline CAP and reductions in weight and BMI percentile (r = 0.320-0.525), whereas LS reduction was correlated positively with baseline LS and reductions in weight, BMI percentile, aspartate transaminase, and alanine aminotransferase (r = 0.385-0.625). Multivariate analysis revealed that baseline CAP and reduction in weight were significantly associated with CAP reduction, whereas reduction in weight and alanine aminotransferase were significantly associated with LS reduction. Short-term weight control by hospital admission (24.9 ± 9.5 days) provided significantly higher reductions in weight and BMI percentile (both P < 0.001) and was associated with reductions of CAP and LS (P = 0.04 and 0.01) compared with regular hospital visit-supported self-directed weight management (0.9 ± 0.8 years).

CONCLUSIONS

Weight reduction in obese pediatric NAFLD patients resulted in reduced hepatic fat deposition and liver stiffness. Weight control by short-term hospital admission is an alternative approach to regular hospital visit-supported self-directed weight management in NAFLD patients who fail to reduce obesity.

Recent advances in non-invasive diagnosis and medical management of non-alcoholic fatty liver disease in adult

Background

Number of non-alcoholic fatty liver disease (NAFLD) cases is increasing over time due to alteration of food habit, increase incidence of metabolic syndrome, and lack of exercise. Liver biopsy is the test for diagnosis and staging of NAFLD, but nowadays several biochemical markers, scoring systems, and imaging studies are available to diagnose and stage NAFLD which is linked to end-stage liver disease, hepatocellular cancer, and elevated cardiovascular- and cancer-related morbidity and mortality. Therefore urgent diagnosis and management are required to avoid complications related to NAFLD. This review summarizes recent advances in diagnosis and medical management of non-alcoholic fatty liver disease.

Main text

Recently published studies from PubMed, Red Cross, Copernicus, and also various previous studies were reviewed. We have discussed various non-invasive methods for detection of non-alcoholic fatty liver disease, non-alcoholic steatohepatitis (NASH), and hepatic fibrosis. Non pharmacological therapies for NAFLD, indications, and approved medications for NAFLD and other commonly used non-approved medications have been discussed in this review article.

Conclusions

Multiple non-invasive tests are available for diagnosis of NAFLD, and its different stages however gold standard test is liver biopsy. NALFD without NASH and significant fibrosis is treated by lifestyle modifications which include moderate to vigorous exercise and diet modification. To improve hepatic steatosis, minimum of 3–5% of body weight loss is necessary, but > 7–10% weight reductions is required for histological improvement in NASH and fibrosis. Pharmacotherapy is indicated when patient is having NASH with significant fibrosis.