Ultrasonography as a non-invasive tool for detection of nonalcoholic fatty liver disease in overweight/obese Egyptian children

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.

Prevalence of incidental sonographic findings of hepatic steatosis in children under 4 years of age

BACKGROUND

The age of onset of nonalcoholic fatty liver disease (NAFLD) and its prevalence in young children is incompletely understood.

OBJECTIVE

We sought to evaluate the prevalence of ultrasound findings of hepatic steatosis in a cohort of children less than 4 years of age.

MATERIALS AND METHODS

This is an institutional review board-approved retrospective review of ultrasounds performed on children less than 4 years of age from January 2022 to August 2022 at a single quaternary care center. Two independent blinded reviewers evaluated for qualitative and semi-quantitative findings of hepatic steatosis. Per prior literature, hepatorenal index (HRI)>1.75 was used as a threshold suggestive of hepatic steatosis. Chi-square, Mann-Whitney U test, and logistic regression analyses were performed for univariable and multivariable statistical analyses. Kappa statistics were used to assess agreement between reviewers.

RESULTS

Eighty-five males and 102 females, median age of 1.1 years (interquartile range 2.1 years), were included. Qualitative findings of hepatic steatosis were seen in 26/187 (14%; 95% CI 10-20%). An HRI>1.75 was present in 15/187 (8%; 95% CI: 5-13%) of examinations, including 11 females and 4 males, and 7/123 (6%) participants <2 years old. Among participants with overweight or obesity, 8/43 (19%) had HRI>1.75 vs. 7/144 (5%) participants without overweight or obesity (P=0.004). Each percentile increase in anthropometrics percentile (weight-to-length or BMI, depending on age) was associated with 22 increased odds of HRI>1.75 (P=0.02).

CONCLUSION

Prevalence of sonographic findings of hepatic steatosis in an unselected sample of preschool-age children is 8-14%, and are more common in participants with overweight/obesity.

Early myocardial functional abnormalities in primary dyslipidemia: clinical and echocardiographic observations in young children from a highly consanguineous population

BACKGROUND

Dyslipidemia is a major health problem among children and adolescents worldwide due to its significant association with cardiovascular disease. Primary dyslipidemias are commonly familial syndromes that can be completely asymptomatic.

PURPOSE

Apart from the risk of coronary artery disease (CAD), limited data are currently available on the direct effects of dyslipidemia on myocardial function in children.

METHODS

We recruited 25 children with primary dyslipidemia (14 with isolated hypercholesterolemia, 4 with isolated hypertriglyceridemia, and 7 with combined dyslipidemia). Relevant clinical manifestations and laboratory and radiological investigations were evaluated. Pulsed-wave Doppler and tissue Doppler imaging echocardiography were performed for all recruited patients and the results were compared with those of 15 age- and sex-matched healthy children.

RESULTS

The median age of the dyslipidemic children was 8 years (range, 1.5-16 years). A family history was documented in 13 cases (52%), while 18 (72%) had consanguineous parents. None of the dyslipidemic children had a personal history or clinical manifestations of CAD. In contrast, echocardiographic findings differed in several diastolic function parameters of both right and left ventricles in dyslipidemic children compared to controls. Based on normalized z scores, aortic valve narrowing was detected in 7 patients (28%), while narrowing of the aortic sinus (sinus of Valsalva) was detected in 15 patients (60%).

CONCLUSION

Different types of primary dyslipidemia produce functional myocardial abnormalities early in childhood. Biochemical and echocardiographic screening of high-risk children is advised to minimize the incidence of serious cardiovascular complications.

Relationship between the prevalence and severity of non‐alcoholic fatty liver disease and coronary artery disease: Findings from a cross‐sectional study of a referral center in northeast Iran

Background and Aim

Non‐alcoholic fatty liver disease (NAFLD) is becoming increasingly prevalent worldwide, and cardiovascular diseases are the most common cause of death in NAFLD patients. The present study aimed to evaluate the possible relationship between the presence and severity of NAFLD and coronary artery disease (CAD).

Methods

A cross‐sectional study was conducted on 296 patients (122 men and 174 women, with mean age 54.10 ± 9.33 years) referred to the catheterization laboratory of Imam Reza Hospital affiliated to the Mashhad University of Medical Sciences, Mashhad, Iran, for elective coronary angiography to investigate the presence and severity of CAD. Additionally, all patients underwent abdominal ultrasonography (USG) to detect NAFLD and its severity.

Results

Among the 296 patients, 187 (63.2%) had CAD and 160 (50.1%) had NAFLD. NAFLD patients had significantly higher prevalence of obesity (odds ratio [OR] = 1.047, 95% confidence interval [CI] = 1.002–1.094), hypertension (OR = 1.909, 95% CI = 1.027–3.55), hyperlipidemia (OR = 3.474, 95% CI = 1.862–6.482), and CAD (OR = 2.009, 95% CI = 1.100–3.669). The percentage of patients with normal vessels was higher in the non‐NAFLD group, followed by the group with mild and severe NAFLD (P < 0.001). However, single‐ and multi‐vessel disease incidences among the non‐NAFLD, mild, and severe NAFLD groups were 36.1, 43.1, and 63.7%, respectively. Interestingly, the percentage of patients with two‐vessel stenosis was significantly higher in severe NAFLD patients than mild and non‐NAFLD patients (P < 0.001).

Conclusion

The prevalence and severity of NAFLD were independently associated with CAD. Mild NAFLD was primarily observed among patients with normal and non‐obstructive coronary artery patients, while severe NAFLD was more frequent in extensive CAD patients with multi‐vessel disease.

Biochemical predictors of metabolically unhealthy obesity in children and adolescents

BACKGROUND

Children and adolescents with obesity can now be classified according to metabolic profile, as those with metabolically healthy obesity (MHO) and those with metabolically unhealthy obesity (MUO). We aimed to determine the prevalence of MUO and identify its biochemical predictors in pediatric patients with obesity.

METHODS

We evaluated the medical records of 187 boys and girls with obesity. The children were divided into MHO and MUO groups, and anthropometric and biochemical parameters were assessed. Oral glucose tolerance test (OGTT) was used to identify impaired glucose regulation and hyperinsulinism, and binary logistic regression analysis was used to determine predictors of MUO in children with obesity.

RESULTS

Of the 187 children, MUO was found in 71.7% (n=134) and MHO in 28.3% (n=53); those in the MHO group were younger than those in the MUO group. Blood pressure, triglyceride, total cholesterol, and uric acid levels were significantly higher in the MUO group than in the MHO group. Further, the MUO group exhibited a significantly higher level of insulin resistance (p<0.05) than the MHO group. Serum levels of uric acid and homeostasis model assessment of insulin resistance index (HOMA-IR) were confirmed as biochemical predictors of the MUO phenotype in children with obesity.

CONCLUSIONS

The ratio of MUO in children with obesity was relatively high; further, serum levels of uric acid and HOMA-IR can be used as biochemical predictors of MUO.

Fatty Liver through the Ages- Non-Alcoholic Steatohepatitis (NASH)

BACKGROUND

The global epidemic of obesity and type 2 diabetes mellitus is the main driver of the growing global prevalence of non-alcoholic fatty liver disease (NAFLD). We aimed to review the current literature on NAFLD and NASH as it impacts children and adults.

METHODS

We performed a literature search on fatty liver specifically non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) among children and adults.

RESULTS

The prevalence of NAFLD in children ranges from 8%-12% while the prevalence in adults ranges 25%-48%. The prevalence of NASH among children with NAFLD is 23% while it ranges from 13% to 65% in the adults. There are similar risk factors for NAFLD among children and adults. However, in children, the diagnostic tests in the studies of NAFLD are limited to elevation of ALT level or a liver biopsy. In adults, additional diagnostic modalities, including non-invasive tests (NITs), have been used. From the spectrum of NAFLD, those with NASH are predominantly at risk of progressive liver disease to cirrhosis and liver-related mortality. NAFLD is associated with impairment of health-related quality of life and substantial economic burden.

CONCLUSION

The comprehensive burden (clinical, HRQL and economic) of NAFLD is high and increasing.

Defining paediatric metabolic (dysfunction)-associated fatty liver disease: an international expert consensus statement

The term non-alcoholic fatty liver disease (NAFLD), and its definition, have limitations for both adults and children. The definition is most problematic for children, for whom alcohol consumption is usually not a concern. This problematic definition has prompted a consensus to rename and redefine adult NAFLD associated with metabolic dysregulation to metabolic (dysfunction)-associated fatty liver disease (MAFLD). Similarities, distinctions, and differences exist in the causes, natural history, and prognosis of fatty liver diseases in children compared with adults. In this Viewpoint we, an international panel, propose an overarching framework for paediatric fatty liver diseases and an age-appropriate MAFLD definition based on sex and age percentiles. The framework recognises the possibility of other coexisting systemic fatty liver diseases in children. The new MAFLD diagnostic criteria provide paediatricians with a conceptual scaffold for disease diagnosis, risk stratification, and improved clinical and multidisciplinary care, and they align with a definition that is valid across the lifespan.

Use of Anthropometry Versus Ultrasound for the Assessment of Body Fat and Comorbidities in Children With Obesity

OBJECTIVES

We aimed to examine the association between abdominal fat measured by ultrasound and anthropometric indices in children with obesity, and those with normal weight. We also examined the association between anthropometry and fat measures in the prediction of comorbidities in children with obesity.

METHODS

Forty children with body mass index of >95th percentile were included as cases, and a comparable group of 32 healthy average-weight peers were included as controls in this study. All children underwent clinical assessment, anthropometric measures, and evaluation of abdominal subcutaneous fat (SCF) and visceral fat by ultrasound. Fasting blood sugar, serum transaminases, and lipid profile of all the included children were also evaluated.

RESULTS

Children with obesity had a mean age of 8.7 ± 2.9 years (range 3-13). The SCF and intraperitoneal fat (IPF) values correlated well with each other and with anthropometric measurements in children with obesity. Among all the included cases, 90% were metabolically unhealthy, 70% had hypertension, 52.5% had dyslipidemia, and 22.5% had echogenic liver. Anthropometric measures, abdominal SCF and IPF were higher in children with complications. SCF was observed as a good predictor for hepatic echogenicity among the measured ultrasound parameters (P: 0.03, odds ratio 4.6). The best cutoff value for SCF in cases with hepatic echogenicity was 23.2 mm with an overall accuracy of 80%.

CONCLUSIONS

In children with obesity, abdominal SCF and IPF correlated well with anthropometric measures and were higher in children with comorbidities. This finding, however, did not predict comorbidities apart from those with echogenic liver.

Nonalcoholic Liver Disease in Children and Adolescents

Pediatric nonalcoholic fatty liver disease (NAFLD) is the most common cause of liver disease in children. The spectrum of NAFLD ranges from steatosis to nonalcoholic steatohepatitis (NASH) to fibrosis. Obesity rates in children continue to rise and, as a result, NAFLD in children is becoming more prevalent. The pathophysiology, natural history, and progression of disease are still being elucidated but NAFLD/NASH in children may represent a more severe phenotype that will benefit from early identification and management.

A Practical Approach to Quantitative Grayscale Ultrasound Analysis of Hepatic Steatosis in Pediatric Patients Using a Picture Archiving and Communication System-Based Tool

OBJECTIVES

To evaluate the efficacy of a picture archiving and communication system (PACS)-based ultrasound (US) quantification technique for diagnosis of hepatic steatosis in a pediatric population.

METHODS

Abdominal US images of 49 pediatric patients (≤18 years) with histopathologically proven diagnoses of hepatic steatosis (n = 17), nonsteatotic liver disease (n = 19), and a normal liver (n = 13) were retrospectively reviewed. Patient demographics, the fibrosis stage, and the steatosis grade were obtained from the database. Quantitative grayscale measurements of the echo intensity level of the liver and kidneys were performed on the US images using the PACS measuring tool. The hepatorenal ratio was obtained by dividing mean liver by mean kidney values. The heterogeneity index for the liver was calculated by dividing the liver standard deviation by mean liver values. Hepatorenal ratio and heterogeneity index values of the 3 groups were correlated with pathologic results and compared by a 1-way analysis of variance. A receiver operating characteristic curve analysis was performed, and cutoff values were determined.

RESULTS

The hepatorenal ratio of the hepatic steatosis group was significantly greater than those of the control and nonsteatotic liver disease groups (P < .001). The heterogeneity index of the hepatic steatosis group was significantly greater than that of the control group (P = .046). For a hepatorenal ratio cutoff value of 1.5, 88.2% sensitivity, 91.4% specificity, 88.3% positive predictive value, and 94.1% negative predictive value were obtained for predicting hepatic steatosis.

CONCLUSIONS

PACS-based quantitative grayscale US quantification is a safe, accurate, and easily applicable objective method for the diagnosis of hepatic steatosis in children. A hepatorenal ratio of greater than 1.5 can be used as a conservative parameter, permitting increased confidence in discriminating hepatic steatosis from other conditions.

Acoustic radiation force impulse imaging for detection of liver fibrosis in overweight and obese children

Background Acoustic radiation force impulse (ARFI) is a non-invasive alternative to a liver biopsy for the evaluation of liver fibrosis (LF). Purpose To investigate the potential usefulness of acoustic radiation force impulse ARFI for detecting LF in overweight and obese children Material and Methods A cross-sectional study was conducted in 148 schoolchildren. A diagnosis of non-alcoholic fatty liver disease (NAFLD) and LF was based on ultrasound (US) and ARFI shear wave velocity (SWV). Results The laboratory parameters were normal in all the children. NAFLD was observed in 50 children (33.8%). The median SWV was 1.18 ± 0.28 m/s. Differences between ARFI categories and hepatic steatosis grades were observed (χ2 = 43.38, P = 0.0005). No fibrosis or insignificant fibrosis (SWV ≤ 1.60 m/s) was detected in 137 children (92.5%), and significant fibrosis (SWV > 1.60 m/s) in 11 children (7.5%), nine of whom had normal US or mild steatosis. Conclusion The present study is the first to evaluate the utility of the ARFI technique for detecting LF in overweight and obese children. The results of the study suggest that children with normal laboratory parameters such as normal liver ultrasound or mild steatosis may present with significant LF.

Diffuse Liver Diseases: Role of imaging

Nowadays, the most common imaging techniques allow to study focal liver lesions with high diagnostic accuracy but a relatively recent emerging field of interest is represented by diffuse liver disease. They include a variegated series of storage and metabolic pathologies (ie, iron overload disorders and steatosis) requiring a precise diagnosis not always possible at imaging due to the overlapping of findings at conventional ultrasound, CT, or MR studies. In recent years, several imaging tecniques and specific softwares have been developed, especially for ultrasound and MR imaging, in order to identify different parameters useful in the noninvasive recognition and follow-up of these diffuse processes involving the liver. The aim of this article is to describe the most common and useful imaging findings of the most common and uncommon diffuse liver diseases illustrating the newest imaging technologies and developments at our disposal with corresponding advantages, limitations, and pitfalls.

Non-Alcoholic Fatty Liver Disease in Africa and Middle East: An Attempt to Predict the Present and Future Implications on the Healthcare System

Non-alcoholic fatty liver disease (NAFLD) encompasses a group of hepatic diseases that range in severity. NAFLD is increasingly recognized as an epidemic among different populations, including those in Africa and the Middle East. The objective of this narrative review is to document the prevalence of and risk factors for NAFLD in Africa and the Middle East and the potential implications on the healthcare systems. An in-depth search on Google Scholar, Medline and PubMed was conducted using the terms "non-alcoholic fatty liver disease" and "non-alcoholic steatohepatitis", in addition to "prevalence and risk factors for NAFLD", with special emphasis on Africa and the Middle East countries. There were three types of epidemiological studies that included prevalence, risk factors and management/complications of NAFLD. There was noticeable variation in the prevalence of NAFLD among different countries, based on the variation in the prevalence of risk factors (type 2 diabetes, obesity, metabolic syndrome and dyslipidemia) and the diagnostic tool used in the study. However, the highest prevalence rate was reported in some Middle East countries. In Africa, there were few studies about NAFLD and most reported variable prevalence rates. There is an increasing prevalence of NAFLD as a result of the increasing risk factors, particularly in the Middle East, while in Africa, the situation is still unclear. Health providers in these regions are faced with many challenges that need urgent plans.

Screening for non-alcoholic fatty liver disease in children: do guidelines provide enough guidance?

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in the industrialized world in children. Its high prevalence and important health risks make NAFLD highly suitable for screening. In practice, screening is widely, albeit not consistently, performed.

AIM

To review the recommendations on screening for NAFLD in children.

METHOD

Recommendations on screening were reviewed from major paediatric obesity guidelines and NAFLD guidelines. A literature overview is provided on open questions and controversies.

RESULTS

Screening for NAFLD is advocated in all obesity and most NAFLD guidelines. Guidelines are not uniform in whom to screen, and most guidelines do not specify how screening should be performed in practice. Screening for NAFLD remains controversial, due to lack of a highly accurate screening tool, limited knowledge to predict the natural course of NAFLD and limited data on its cost effectiveness.

CONCLUSIONS

Guidelines provide little guidance on how screening should be performed. Screening for NAFLD remains controversial because not all conditions for screening are fully met. Consensus is needed on the optimal use of currently available screening tools. Research should focus on new accurate screening tool, the natural history of NAFLD and the cost effectiveness of different screening strategies in children.

NASPGHAN Clinical Practice Guideline for the Diagnosis and Treatment of Nonalcoholic Fatty Liver Disease in Children: Recommendations from the Expert Committee on NAFLD (ECON) and the North American Society of Pediatric Gastroenterology, Hepatology and Nutrition (NASPGHAN)

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent chronic liver disease that occurs in the setting of insulin resistance and increased adiposity. It has rapidly evolved into the most common liver disease seen in the pediatric population and is a management challenge for general pediatric practitioners, subspecialists, and for health systems. In this guideline, the expert committee on NAFLD reviewed and summarized the available literature, formulating recommendations to guide screening and clinical care of children with NAFLD.

Associations between Serum Uric Acid and the Remission of Non-Alcoholic Fatty Liver Disease in Chinese Males

Epidemiological studies suggest that higher serum uric acid (sUA) level is significantly associated with nonalcoholic fatty liver disease (NAFLD) development. However, little information is available on the relationships between sUA and NAFLD remission. In the present study, 841 NAFLD males (30-75 years) were recruited from a Chinese prospective cohort study (PMMJS) and followed up for five years. The baseline sUA levels of participants were categorized into four quartiles: 191 μmol/L≤ sUA ≤ 347 μmol/L, 347 μmol/L < sUA ≤ 392 μmol/L, 392 μmol/L < sUA ≤ 441 μmol/L and 441 μmol/L<SUA≤676 μmol/L. As the results show, participants with elevated sUA levels at baseline were significantly associated with the decreased rate of NAFLD remission at the end of study (p<0.0001). After adjustment, RR (95%CI) for remitted NAFLD comparing Q1 to Q3 vs Q4 of sUA were 2.95 (1.49-5.83), 2.40 (1.22-4.73) and 1.39 (0.67-2.86), respectively. Furthermore, the sensitivity analysis showed these significant associations were not affected even after exclusion of participants who had hypertension, diabetes mellitus, MetS and hyperlipidemia. Additionally, the presence of the lowest quartile of sUA levels was still significantly associated with remitted NAFLD when the study population was stratified according to the smoking, and the median values of age, ALT, AST, serum creatinine, HDL-C and LDL-C. Therefore, our present study extended the previous findings and suggested that modulation of sUA levels may attenuate the progression of NAFLD.

Prevalence and sonographic changes compatible with fatty liver disease in patients referred for abdominal ultrasound examination in Aracaju, SE

Objective

To estimate the prevalence and evaluate sonographic findings compatible with changes consistent with hepatic steatosis in patients referred for abdominal ultrasonography at four reference centers in Aracaju, SE, Brazil.

Materials and Methods

Prospective, descriptive survey, with analytical and quantitative approach, comprising abdominal ultrasonography scans performed with a convex, dynamic 3.75 MHz transducer. Liver dimensions and parenchymal echotexture were evaluated, classifying hepatic steatosis into grades (1, 2 or 3). The SPSS^® 22.0 software was used for statistical analysis, adopting p < 0.05 as significance level.

Results

A total of 800 individuals (561 women and 239 men) were evaluated. The prevalence of steatosis was 29.1%, and the male patients were most affected, presenting with more advanced grades of disease (p = 0.021), as follows: 119 grade 1 (51.0%); 94 grade 2 (40.4%); and 20 grade 3 (8.6%). The median age patients' was 46 years.

Conclusion

In the present study sample, the prevalence of hepatic steatosis was high, particularly in the male patients. Ultrasonography is suggested as a first choice for the diagnosis of this condition, considering its wide availability, low cost and absence of side effects or risks to the patient.

Relationship between Neck Circumference and Non-Alcoholic Fatty Liver Disease in Childhood Obesity

OBJECTIVE

The aim of this study was to establish the association between anthropometric parameters and non-alcoholic fatty liver disease (NAFLD) and to determine the most reliable measurement as a parameter in predicting NAFLD.

METHODS

Two-hundred fifty-three obese children of ages 10 to 18 years were enrolled in this study. Anthropometric data and metabolic parameters such as fasting blood glucose, insulin and lipid levels, were measured. Liver function tests were assessed. NAFLD was determined by ultrasound.

RESULTS

Most metabolic parameters and anthropometric indices were significantly higher in children with NAFLD. A univariate logistic regression analysis was performed, taking NAFLD status as the dependent variable and anthropometric parameters as the independent variables. NAFLD was affected significantly by the anthropometric values. The multiple logistic regression analysis showed that neck circumference (NC) was the only parameter which determined the risk in both genders. Each 1 cm increase in the NC increased the risk of NAFLD 1.544-fold (p<0.001, 95% confidence interval (CI): 1.357-2.214) in the boys and 1.733-fold (p=0.001, 95% CI: 1.185-2.012) in the girls. Receiver operating characteristic analysis was performed to compare the reliability of anthropometric measurements. NC was observed to be a better indicator.

CONCLUSION

Measurement of the NC was shown to be associated with NAFLD in children. We suggest the use of NC as a novel, simple, practical, and reliable anthropometric index in predicting children at risk for NAFLD.

Sonographic evaluation of visceral and subcutaneous fat in obese children

Objective

To evaluate sonographic measurements of visceral and subcutaneous fat in children, and to investigate the usefulness of preperitoneal fat (PF) and the abdominal wall fat index (AFI) as parameters to determine visceral fat and presence of nonalcoholic fatty liver disease (NAFLD) in obese children.

Materials and Methods

A case-control study of a sample including 44 children (22 cases and 22 controls) matched by sex and age. The Student t test and the Fisher exact test were utilized in the descriptive and bivariate analysis.

Results

The sonographic parameters evaluated - subcutaneous cell tissue, PF and intraperitoneal fat, and NAFLD - presented high statistical association with body mass index. NAFLD was observed in eight obese patients (36.36%), and PF and AFI were the variables with highest statistical significance, with p < 0.0001.

Conclusion

Ultrasonography is useful tool in the differentiation and quantification of visceral and subcutaneous fat in children. The measures of PF and AFI are useful in the assessment of visceral fat and NAFLD in obese children.

Ultrasound in chronic liver disease

Background

With the high prevalence of diffuse liver disease there is a strong clinical need for noninvasive detection and grading of fibrosis and steatosis as well as detection of complications.

Methods

B-mode ultrasound supplemented by portal system Doppler and contrast-enhanced ultrasound are the principal techniques in the assessment of liver parenchyma and portal venous hypertension and in hepatocellular carcinoma surveillance.

Results

Fibrosis can be detected and staged with reasonable accuracy using Transient Elastography and Acoustic Radiation Force Imaging. Newer elastography techniques are emerging that are undergoing validation and may further improve accuracy. Ultrasound grading of hepatic steatosis currently is predominantly qualitative.

Conclusion

A summary of methods including B-mode, Doppler, contrast-enhanced ultrasound and various elastography techniques, and their current performance in assessing the liver, is provided.

Teaching Points

• Diffuse liver disease is becoming more prevalent and there is a strong clinical need for noninvasive detection.

• Portal hypertension can be best diagnosed by demonstrating portosystemic collateral venous flow.

• B-mode US is the principal US technique supplemented by portal system Doppler.

• B-mode US is relied upon in HCC surveillance, and CEUS is useful in the evaluation of possible HCC.

• Fibrosis can be detected and staged with reasonable accuracy using TE and ARFI.

• US detection of steatosis is currently reasonably accurate but grading of severity is of limited accuracy.

Evidence and recommendations for imaging liver fat in children, based on systematic review

BACKGROUND & AIMS

Fatty liver is a common problem in children and increases their risk for cirrhosis, diabetes, and cardiovascular disease. Liver biopsy is the clinical standard for diagnosing and grading fatty liver. However, noninvasive imaging modalities are needed to assess liver fat in children. We performed a systematic review of studies that evaluated imaging liver fat in children.

METHODS

We searched PubMed for original research articles in peer-reviewed journals from January 1, 1982, through December 31, 2012, using the key words "imaging liver fat." Studies included those in English, and those performed in children from birth to 18 years of age. To be eligible for inclusion, studies were required to measure hepatic steatosis via an imaging modality and a quantitative comparator as the reference standard.

RESULTS

We analyzed 9 studies comprising 610 children; 4 studies assessed ultrasonography and 5 studies assessed magnetic resonance imaging (MRI). Ultrasonography was used in the diagnosis of fatty liver with positive predictive values of 47% to 62%. There was not a consistent relationship between ultrasound steatosis score and the reference measurement of hepatic steatosis. Liver fat as measurements by MRI or by spectroscopy varied with the methodologies used. Liver fat measurements by MRI correlated with results from histologic analyses, but sample size did not allow for an assessment of diagnostic accuracy.

CONCLUSIONS

Available evidence does not support the use of ultrasonography for the diagnosis or grading of fatty liver in children. Although MRI is a promising approach, the data are insufficient to make evidence-based recommendations regarding its use in children for the assessment of hepatic steatosis.

Non-alcoholic fatty liver disease and risk of in-stent restenosis after bare metal stenting in native coronary arteries

In-stent restenosis (ISR) remains the most common complication of percutaneous coronary intervention. Due to shared risk factors, it is postulated that non-alcoholic fatty liver disease (NAFLD) patients have an increased risk of ISR. This study aimed to determine the association between NAFLD and ISR in patients after bare metal stenting. This study included a cohort of 210 consecutive patients (150 men and 60 women) undergoing follow-up angiography. The primary end-point was angiographic ISR. Multivariate logistic regression analysis was used to identify independent risk factors for ISR. The cumulative ISR rate during follow-up was analyzed by Kaplan-Meier method. Subgroup analyses were also done for different gender. The ISR rate was 29.5%. Patients with NAFLD had a significantly higher prevalence of ISR than patients without NAFLD (43.3 vs. 16.0%, P < 0.001). In logistic regression analysis, NAFLD was associated with increased ISR, independent of low-density lipoprotein cholesterol, body mass index (adjusted odds ratio: 2.688, 95% confidence intervals: 1.285-5.537, P < 0.001). Male NAFLD patients had a higher prevalence of ISR than patients without NAFLD (48.4 vs. 15.3%, P < 0.001), while the prevalence of ISR in female patients with and without NAFLD were comparable (7.7 vs. 17.0%, P = 0.404). Kaplan-Meier analysis showed a significant association between NAFLD and ISR in all patients (log-rank P = 0.008) and in male subgroup (log-rank P = 0.033), but not in female subgroup (log-rank P = 0.313). This preliminary study suggests that NAFLD could independently associate with a high prevalence of ISR, especially in male patients.