Appropriateness of a donor liver with respect to macrosteatosis: application of artificial neural networks to US images--initial experience

Nonalcoholic Fatty Liver Disease: Changes in Gut Microbiota and Blood Lipids

Background and Aims

The global prevalence of nonalcoholic fatty liver disease (NAFLD) is 25%. This study aimed to explore differences in the gut microbial community and blood lipids between normal livers and those affected by NAFLD using 16S ribosomal deoxyribonucleic acid sequencing.

Methods

Gut microbiome profiles of 40 NAFLD and 20 non-NAFLD controls were analyzed. Information about four blood lipids and 13 other clinical features was collected. Patients were divided into three groups by ultrasound and FibroScan, those with a normal liver, mild FL (FL1), and moderate-to-severe FL (FL2). FL1 and FL2 patients were divided into two groups, those with either hyperlipidemia or non-hyperlipidemia based on their blood lipids. Potential keystone species within the groups were identified using univariate analysis and a specificity-occupancy plot. Significant difference in biochemical parameters ion NAFLD patients and healthy individuals were identified by detrended correspondence analysis and canonical correspondence analysis.

Results

Decreased gut bacterial diversity was found in patients with NAFLD. Firmicutes/Bacteroidetes decreased as NAFLD progressed. Faecalibacterium and Ruminococcus 2 were the most representative fatty-related bacteria. Glutamate pyruvic transaminase, aspartate aminotransferase, and white blood cell count were selected as the most significant biochemical indexes. Calculation of areas under the curve identified two microbiomes combined with the three biochemical indexes that identified normal liver and FL2 very well but performed poorly in diagnosing FL1.

Conclusions

Faecalibacterium and Ruminococcus 2, combined with glutamate pyruvic transaminase, aspartate aminotransferase, and white blood cell count distinguished NAFLD. We speculate that regulating the health of gut microbiota may release NAFLD, in addition to providing new targets for clinicians to treat NAFLD.

Artificial Intelligence in Liver Diseases: Recent Advances

Liver diseases cause a significant burden on public health worldwide. In spite of great advances during recent years, there are still many challenges in the diagnosis and treatment of liver diseases. During recent years, artificial intelligence (AI) has been widely used for the diagnosis, risk stratification, and prognostic prediction of various diseases based on clinical datasets and medical images. Accumulative studies have shown its performance for diagnosing patients with nonalcoholic fatty liver disease and liver fibrosis and assessing their severity, and for predicting treatment response and recurrence of hepatocellular carcinoma, outcomes of liver transplantation recipients, and risk of drug-induced liver injury. Herein, we aim to comprehensively summarize the current evidence regarding diagnostic, prognostic, and/or therapeutic role of AI in these common liver diseases.

Noninvasive assessment of paediatric hepatic steatosis by using attenuation imaging

OBJECTIVES

To evaluate the diagnostic performance of attenuation imaging (ATI) with an ultrasound scanner (US) in the detection of paediatric hepatic steatosis.

METHODS

Ninety-four prospectively enrolled children were classified into normal weight and overweight/obese (OW/OB) groups according to body mass index (BMI). US findings, including hepatic steatosis grade and ATI value, were examined by two radiologists. Anthropometric and biochemical parameters were obtained, and nonalcoholic fatty liver disease (NAFLD) scores, including the Framingham steatosis index (FSI) and hepatic steatosis index (HSI), were calculated.

RESULTS

After screening, 49 OW/OB and 40 normal weight children aged 10-18 years old (55 males and 34 females) participated in this study. The ATI value was significantly higher in the OW/OB group than in the normal weight group and showed a significant positive correlation with BMI, serum alanine transferase (ALT), uric acid, and NAFLD scores (p < 0.05). In the multiple linear regression adjusted for age, sex, BMI, ALT, uric acid, and HSI, ATI showed a significant positive association with BMI and ALT (p < 0.05). The receiver operating characteristic analysis showed a very good ability of ATI to predict hepatic steatosis. The intraclass correlation coefficient (ICC) of interobserver variability was 0.92, and the ICCs of intraobserver variability were 0.96 and 0.93 (p < 0.05). According to the two-level Bayesian latent class model analysis, the diagnostic performance of ATI showed the best performance for predicting hepatic steatosis among other known noninvasive NAFLD predictors.

CONCLUSIONS

This study suggests that ATI is an objective and possible surrogate screening test for detecting hepatic steatosis in paediatric patients with obesity.

CLINICAL RELEVANCE STATEMENT

Using ATI as a quantitative tool in hepatic steatosis allows clinicians to estimate the extent of the condition and track changes over time. This is helpful for monitoring disease progression and guiding treatment decisions, especially in paediatric practice.

KEY POINTS

• Attenuation imaging is a noninvasive US-based method for the quantification of hepatic steatosis. • Attenuation imaging values were significantly higher in the OW/OB and steatosis groups than in the normal weight and no steatosis groups, respectively, with a meaningful correlation with known clinical indicators of nonalcoholic fatty liver disease. • Attenuation imaging performs better than other noninvasive predictive models used to diagnose hepatic steatosis.

Metabolic risk factors in prepubertal and pubertal patients with overweight and obesity

OBJECTIVES

Metabolic syndrome (MetS) is a cluster of conditions linked to obesity that increases cardiovascular risk. We evaluated the frequency of clinical abnormalities associated with overweight and obesity in childhood, to determine whether a diagnosis of MetS is appropriate in this population.

METHODS

Cross-sectional study with 116 pubertal and prepubertal children with a mean age (SD) of 10.9 (2.5) years, with overweight and obesity. We defined MetS using the International Diabetes Federation criteria, regardless of the age.

RESULTS

45 patients met the criteria, 20 had at least one metabolic abnormality in addition to a high waist circumference (WC), and seven with WC below percentile 90th, had at least one metabolic abnormality. The prepubertal had higher zBMI [3.1 (2.6-3.8) vs. 2.8 (2.4-3.3); p=0.037], less lean body mass (kg) [27.13 (7.3) vs. 34.13 (9.8); p=0.005] and a similar frequency of non-alcoholic fatty liver disease (NAFLD) compared to the pubertal [44.7 vs. 35.9; p=0.323]. Prepubertal with NAFLD had higher zBMI, lower HDL levels, higher TG/HDL ratios and higher fat percentages; while pubertal with NAFLD had higher WC/height, aspartate aminotransferase and oxaloacetic transaminase.

CONCLUSIONS

The diagnosis of MetS in childhood is not fundamental. Individualized management, focusing on the earliest age groups, in which we identified a more severe degree of obesity, should be done. We also recommend screening for NAFLD in all ages, due to the high prevalence observed.

Sonographic Markers Are Useful for Detection of Early Vascular Deterioration in Children with Overweight/Obesity: Effect of a 1-Year Combined Nutritional Education and Physical Exercise Program

As in adults, childhood obesity is associated with several metabolic disorders; however, there is little information regarding complex obesity-derived complications such as hepatic steatosis or endothelial dysfunction at early ages. Therefore, the objective of the present study was to analyze the effect of a nutritional and physical exercise program on obesity comorbidities in the form of subclinical atherosclerosis and non-alcoholic fatty liver in young children. A total of 148 children completed the study. For nine months (one academic year), children carried out a nutritional and physical activity program of 3 h/week. Anthropometric, clinical, liver ultrasound and carotid intima-media thickness (cIMT) parameters were evaluated. Our results showed that the program significantly improved anthropometrical parameters, especially regarding BMI and body fat (p < 0.001 and p = 0.004, respectively). The effect on metabolic parameters was limited, although a significant reduction on triglycerides was observed (p = 0.009). The education program had a great influence on the echogenic parameters, since the percentage of children with light steatosis decreased from 35% to 4% at the end of the study. In addition, cIMT also decreased significantly in both groups, although there was no statistically significant differences between groups. In conclusion, detection of early complications of obesity through sonographic parameters may allow early intervention, as in the present study, to prevent obesity co-morbidities in children.

Diagnosis of hepatic steatosis based on ultrasound attenuation imaging is not influenced by liver fibrosis

AIM

Recently, a new technique using attenuation imaging (ATI) was developed to diagnose hepatic steatosis. The aim of this study was to investigate whether ATI for the evaluation of hepatic steatosis is influenced by liver fibrosis.

METHODS

A total of 328 patients with chronic liver disease were enrolled to study the associations between histological hepatic steatosis or liver fibrosis and ATI findings. The interaction between liver fibrosis and ATI was also analyzed.

RESULTS

Median ATI values according to steatosis grade and fibrosis stage increased in line with the progression of liver steatosis (p < 0.001) and fibrosis (p < 0.05). However, in each steatosis grade, ATI values according to fibrosis stage were not significantly increased. In multiple regression analyses for assessment of the effect of their interaction, the p values for fibrosis stage, steatosis grade, and fibrosis stage × steatosis grade were 0.096, <0.001, and 0.077, respectively. Variance inflation factor values for fibrosis stage, steatosis grade, and fibrosis stage × steatosis grade were 1.079, 1.094, and 1.074, respectively.

CONCLUSION

Attenuation imaging values are not influenced by liver fibrosis.

Correlation between Transient Elastography (Fibroscan®) and Ultrasonographic and Computed Tomographic Grading in Pediatric Nonalcoholic Steatohepatitis

PURPOSE

This study aimed to examine the advantages and usefulness of transient elastography (Fibroscan^®) in diagnosing non-alcoholic steatohepatitis in children and adolescents compared to those of abdominal computed tomography and liver ultrasonography.

METHODS

Forty-six children and adolescent participants aged between 6 and 16 years who underwent transient elastography (Fibroscan^®) as well as liver ultrasonography or abdominal computed tomography were included. Thirty-nine participants underwent liver ultrasonography and 11 underwent computed tomography. The physical measurements, blood test results, presence of metabolic syndrome, and the degree of liver steatosis and liver fibrosis were analyzed, and their correlations with transient elastography (Fibroscan^®), abdominal computed tomography, and liver ultrasonography, as well as the correlations between examinations, were analyzed.

RESULTS

Thirty-six participants (78.3%) were boys, and the mean age was 12.29±2.57 years, with a mean body mass index of 27.88±4.28. In the 46 participants, the mean values for aspartate aminotransferase, alanine aminotransferase, and total bilirubin were 89.87±118.69 IU/L, 138.54±141.79 IU/L, and 0.77±0.61 mg/dL, respectively. Although transient elastography (Fibroscan^®) and abdominal computed tomography grading had a statistically significant positive correlation with aspartate aminotransferase and alanine aminotransferase values, the correlations between the results of grading performed by transient elastography (Fibroscan^®), abdominal computed tomography, and liver ultrasonography were not statistically.

CONCLUSION

We confirmed that each examination was correlated with the results of some blood tests, suggesting the usefulness and possibility of diagnosis and treatment of steatohepatitis mediated by transient elastography (Fibroscan^®) in the department of pediatrics.

SGLT2 Inhibitors as the Most Promising Influencers on the Outcome of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD), the most frequent liver disease in the Western world, is a common hepatic manifestation of metabolic syndrome (MetS). A specific cure has not yet been identified, and its treatment is currently based on risk factor therapy. Given that the initial accumulation of triglycerides in the liver parenchyma, in the presence of inflammatory processes, mitochondrial dysfunction, lipotoxicity, glucotoxicity, and oxidative stress, can evolve into non-alcoholic steatohepatitis (NASH). The main goal is to identify the factors contributing to this evolution because, once established, untreated NASH can progress through fibrosis to cirrhosis and, ultimately, be complicated by hepatocellular carcinoma (HCC). Several drugs have been tested in clinical trials for use as specific therapy for NAFLD; most of them are molecules used to cure type 2 diabetes mellitus (T2DM), which is one of the main risk factors for NAFLD. Among the most studied is pioglitazone, either alone or in combination with vitamin E, glucagon-like peptide-1 (GLP-1) receptor agonists, dipeptidyl peptidase-4 (DPP-4) inhibitors. Actually, the most promising category seems to be sodium-glucose cotransporter (SGLT2) inhibitors. Their action is carried out by inhibiting glucose reabsorption in the proximal renal tubule, leading to its increased excretion in urine and decreased levels in plasma. Experimental studies in animal models have suggested that SGLT2 inhibitors may have beneficial modulatory effects on NAFLD/NASH, and several trials in patients have proven their beneficial effects on liver enzymes, BMI, blood lipids, blood glucose, and insulin resistance in NAFLD patients, thus creating strong expectations for their possible use in preventing the evolution of liver damage in these patients. We will review the main pathogenetic mechanisms, diagnostic modalities, and recent therapies of NAFLD, with particular attention to the use of SGLT2 inhibitors.

Prospective assessment of liver stiffness by shear wave elastography in childhood obesity: a pilot study

PURPOSE

The increased incidence of childhood obesity and related non-alcoholic fatty liver disease (NAFLD) has determined the need to identify a non-invasive technique to diagnose and monitor NAFLD. Two-dimensional shear wave elastography (2D-SWE) has emerged as a reliable, non-invasive, tool to evaluate liver tissue elasticity in clinical practice. Aims of this study were to longitudinally evaluate 2D-SWE changes in relation to weight loss, metabolic profile, and body composition modifications and to investigate the correlation between 2D-SWE variation and clinical and biochemical indices of cardio-metabolic risk in obese children.

METHODS

Thirty-three children underwent anthropometric, bioimpedenziometric, fasting biochemical assessments, ultrasound, and SWE evaluations, at baseline (V0) and after a 12-months of follow-up (V12). Diet and physical activity programs have been prescribed to all patients according to European Society of Endocrinology and Pediatric Endocrine Society recommendations. Adherence to the prescribed diet and physical activity program was checked every 3 months during the 12-month of follow-up. Variation of all parameters was evaluated in intragroup and intergroup comparison analysis in children, who had not lost weight (Group A) and those who had lost weight (Group B) at V12. Study population was also analyzed dividing it into two groups with respect to 2D-SWE liver elasticity value ≤10.6 kPa or >10.6 kPa.

RESULTS

A significant reduction of mean 2D-SWE value was demonstrated both in the entire cohort (p = 0.002) and in Group B children (p = 0.004). Intragroup comparison analysis, between V0 and V12, documented a significant decrease of 2D-SWE and BMI SDS and a significant improvement of metabolic profile (decrease of HOMA-IR, HbA1c, oral glucose tolerance test 120-min glucose and insulin, triglycerides, triglycerides/HDL-ratio, transaminases, uric acid, and increase of Matsuda-index and HDL) in children of Group B but not in those of Group A. Intergroup comparison analysis showed significant differences for BMI, BMI SDS, transaminases and several parameters of glucose and lipid metabolism, between Group A and Group B children after 12-months of follow-up. No significant differences were documented with regard to clinical and biochemical variables by dividing the population in accordance with the 2D-SWE cut-off of 10.6 kPa.

CONCLUSIONS

These results suggested a relation between weight loss, metabolic profile improvement and 2D-SWE value reduction. SWE could play a significant role in the non-invasive assessment of NAFLD in children and adolescents with obesity.

Association between Hepatic Steatosis and Obstructive Sleep Apnea in Children and Adolescents with Obesity

BACKGROUND

Owing to the increasing rate of pediatric obesity, its complications such as non-alcoholic fatty liver disease (NAFLD) and obstructive sleep apnea (OSA) have become prevalent already in childhood. We aimed to assess the relationship between these two diseases in a cohort of children with obesity.

METHODS

We enrolled 153 children with obesity (mean age 10.5 ± 2.66, mean BMI 30.9 ± 5.1) showing OSA. Subjects underwent a laboratory evaluation, a cardio-respiratory polysomnography (PSG), and a liver ultrasound.

RESULTS

All subjects had a clinical diagnosis of OSA based on the AHI > 1/h (mean AHI 8.0 ± 5.9; range 2.21-19.0). Of these, 69 showed hepatic steatosis (62.3% as mild, 20.3% as moderate, and 17.4% as severe degree). A strong association between ALT and apnea/hypopnea index (AHI) was observed (p = 0.0003). This association was not confirmed after adjusting for hepatic steatosis (p = 0.53). By subdividing our population according to the presence/absence of steatosis, this association was found only in the steatosis group (p = 0.009). As the severity of steatosis increased, the significance of its association with AHI compared to the absence of steatosis became progressively stronger (all p < 0.0001).

CONCLUSIONS

Hepatic steatosis seems to drive the association between OSA and ALT levels, suggesting a potential pathogenic role of OSA in NAFLD.

The Study of Clinical and Biochemical Parameters in Assessing the Response to the Antiviral Therapy in the Chronic Viral Hepatitis B

Background and Objectives: Hepatitis B virus infection remains a major public health concern. The interaction between hepatitis B virus (HBV) hepatitis B virus and the host inflammatory response is an important contributing factor driving liver damage and diseases outcomes. The management of chronic hepatitis B virus infection is an area of massive unmet clinical need worldwide. Our primary aim for this study was to evaluate biological response rates and sustained virological response in patients with chronic hepatitis B treated with Peg-IFN α-2a/b. The second aim of the study was the identification of metabolic changes and insulin resistance. Materials and Methods: We enrolled in this study 166 patients who fulfilled all inclusion and exclusion criteria. These treatment-naive patients with chronic HBV were treated with Pegylated Interferon α-2a/b. HBV infection was defined by the presence of HBV serological markers (HBsAg, anti-HBsAb, anti-HBcAb, HBeAg, anti HBeAb) by Enzyme-Linked Immuno Sorbent Assay (ELISA) and serum HBV-DNA levels were estimated by a commercially available quantitative polymerase chain reaction (PCR) assay. Results: Patients’ recovery progress has been evaluated by determining the following: age, gender; biochemical tests; alanine aminotransferase, aspartate aminotransferase; serological assays for HBV serological markers (HBsAg, anti-HBsAc/Ab, anti-HBcAc/Ab, HBeAg, anti HBeAc/Ab); molecular tests to detect viral particles, testing for HBV DNA (PCR) to confirm the diagnosis and quantify the number of viral copies in the blood (viremia); liver ultrasound—performed through epigastric and intercostal approach (transversal and longitudinal sections). Conclusions: Our results indicated that only HOMA index values, that of fasting insulin, together with baseline HBV DNA, alanine aminotransferase values, mean blood glucose at the beginning of treatment may be predictive of the early viral response in chronic hepatitis B.

Comparison of Diagnosis Accuracy between a Backpropagation Artificial Neural Network Model and Linear Regression in Digestive Disease Patients: an Empirical Research

Introduction

A Noninvasive diagnosis model for digestive diseases is the vital issue for the current clinical research. Our systematic review is aimed at demonstrating diagnosis accuracy between the BP-ANN algorithm and linear regression in digestive disease patients, including their activation function and data structure.

Methods

We reported the systematic review according to the PRISMA guidelines. We searched related articles from seven electronic scholarly databases for comparison of the diagnosis accuracy focusing on BP-ANN and linear regression. The characteristics, patient number, input/output marker, diagnosis accuracy, and results/conclusions related to comparison were extracted independently based on inclusion criteria.

Results

Nine articles met all the criteria and were enrolled in our review. Of those enrolled articles, the publishing year ranged from 1991 to 2017. The sample size ranged from 42 to 3222 digestive disease patients, and all of the patients showed comparable biomarkers between the BP-ANN algorithm and linear regression. According to our study, 8 literature demonstrated that the BP-ANN model is superior to linear regression in predicting the disease outcome based on AUROC results. One literature reported linear regression to be superior to BP-ANN for the early diagnosis of colorectal cancer.

Conclusion

The BP-ANN algorithm and linear regression both had high capacity in fitting the diagnostic model and BP-ANN displayed more prediction accuracy for the noninvasive diagnosis model of digestive diseases. We compared the activation functions and data structure between BP-ANN and linear regression for fitting the diagnosis model, and the data suggested that BP-ANN was a comprehensive recommendation algorithm.

Performance of Ultrasound Techniques and the Potential of Artificial Intelligence in the Evaluation of Hepatocellular Carcinoma and Non-Alcoholic Fatty Liver Disease

Global statistics show an increasing percentage of patients that develop non-alcoholic fatty liver disease (NAFLD) and NAFLD-related hepatocellular carcinoma (HCC), even in the absence of cirrhosis. In the present review, we analyzed the diagnostic performance of ultrasonography (US) in the non-invasive evaluation of NAFLD and NAFLD-related HCC, as well as possibilities of optimizing US diagnosis with the help of artificial intelligence (AI) assistance. To date, US is the first-line examination recommended in the screening of patients with clinical suspicion of NAFLD, as it is readily available and leads to a better disease-specific surveillance. However, the conventional US presents limitations that significantly hamper its applicability in quantifying NAFLD and accurately characterizing a given focal liver lesion (FLL). Ultrasound contrast agents (UCAs) are an essential add-on to the conventional B-mode US and to the Doppler US that further empower this method, allowing the evaluation of the enhancement properties and the vascular architecture of FLLs, in comparison to the background parenchyma. The current paper also explores the new universe of AI and the various implications of deep learning algorithms in the evaluation of NAFLD and NAFLD-related HCC through US methods, concluding that it could potentially be a game changer for patient care.

MAFLD Criteria Guide the Subtyping of Patients with Fatty Liver Disease

Background and Aims

Metabolic associated fatty liver disease (MAFLD) is diagnosed in patients with hepatic steatosis when they have the following three metabolic conditions: obesity/overweight, diabetes and metabolic dysregulation, either alone or in combination. There is no clarity whether subtypes of MAFLD diagnosed by different metabolic conditions carry different levels of risk for intra- and extra-hepatic organs. This study aims to depict the characteristics of these subtypes in a large population.

Methods

The data were retrieved from the third National Health and Nutrition Examination Surveys of the United States. The clinical and biochemical features in different MAFLD subtypes were compared. The outcome of interest was significant and advanced fibrosis.

Results

Out of 4,087 (31.24%) participants with MAFLD, 1,165 (28.51%) were diagnosed by single metabolic condition, 2,053 (50.23%) by two conditions, and 869 (21.26%) by all three metabolic conditions. With increasing numbers of metabolic conditions, participants tended to be older, were more likely to be female, and had more severe renal impairment and liver fibrosis (P<0.05). MAFLD patients with a lower number of metabolic conditions were more likely to have excessive alcohol consumption. Among MAFLD with single metabolic condition, those diagnosed by diabetes alone had the highest proportion of advanced fibrosis identified by non-invasive fibrosis models (P<0.05).

Conclusion

More metabolic conditions upon the diagnosis of MALFD indicate higher risk of fibrosis. Patients with MAFLD diagnosed by diabetes alone are more likely to have advanced hepatic fibrosis than those with other metabolic conditions alone. Individualized management is required for MAFLD with different subtypes.

The effects of zinc supplementation on metabolic profile and oxidative stress in overweight/obese patients with non-alcoholic fatty liver disease: A randomized, double-blind, placebo-controlled trial

BACKGROUND

Evidence indicates the positive effects of zinc on insulin resistance and oxidative stress in metabolic syndrome or diabetes. Non-alcoholic fatty liver disease (NAFLD) is the main hepatic manifestation of insulin resistance and metabolic syndrome. The present study is the first clinical trial that evaluated the effects of zinc supplementation on metabolic and oxidative stress status in overweight/obese patients with NAFLD undergoing calorie- restriction diet.

METHODS

Fifty six overweight/obese patients with confirmed mild to moderate NAFLD using ultrasonography were randomly allocated to receive 30 mg elemental zinc supplement (n = 29) or placebo (n = 27) along with weight loss diet for 12 weeks. Serum levels of zinc, homeostasis model of assessment-estimated insulin resistance (HOMA-IR), lipid profile, serum superoxide dismutas1 (SOD1) and malondialdhyde (MDA) levels were assessed.

RESULTS

Serum levels of insulin, SOD1, MDA and HOMA-IR were improved in the treatment group (p < 0.05). Within group comparison showed significant reduction in serum FBS, HbA_1C, TC, LDL-c and TG in the treatment group.

CONCLUSION

Zinc supplementation for three months improved insulin resistance and oxidative stress status in overweight/obese NAFLD patients with no beneficial effects on lipid profiles over weight loss diet. Registration ID in IRCT (IRCT NO: 20181005041238N1).

Use of imaging techniques for non-invasive assessment in the diagnosis and staging of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic liver disease and represent a common finding in highly prevalent metabolic disorders (i.e. type 2 diabetes, metabolic syndrome, obesity). Non-alcoholic steatohepatitis (NASH) requires liver biopsy for grading and staging the liver damage by the assessment of steatosis, inflammation and fibrosis. In parallel with the development of numerous 'liquid' biomarkers and algorithms that combine anthropometric and laboratory parameters, innovative hepatic imaging techniques have increasingly been developed to attempt to overcome the need for biopsy, both in diagnosis and staging of NAFLD, and in possible use in the follow-up of the disease. In this review, we focused on the different imaging techniques trying to highlight the strengths and disadvantages of different approaches, particularly for ultrasound techniques, in stratifying liver injury and fibrosis in patients with NAFLD / NASH.

The Effect of Zinc Supplementation on Steatosis Severity and Liver Function Enzymes in Overweight/Obese Patients with Mild to Moderate Non-alcoholic Fatty Liver Following Calorie-Restricted Diet: a Double-Blind, Randomized Placebo-Controlled Trial

The role of zinc is known in balancing the oxidant/antioxidant system and also in improving insulin resistance in many diseases. Recently, in vivo and in vitro studies revealed roles of zinc on lipophagy and suppressing hepatic lipid deposition. The present study is the first double-blind randomized clinical trial that investigated the effect of zinc supplement on clinical manifestations and anthropometric parameters of overweight/obese non-alcoholic fatty liver patients following calorie-restricted diet. Fifty-six overweight/obese subjects with confirmed non-alcoholic fatty liver disease (NAFLD) using ultrasonography were randomized to treatment (calorie-restricted diet plus 30 mg/day zinc supplement) or placebo (calorie-restricted diet and placebo) groups. Serum liver enzymes and liver steatosis were measured at the baseline and 12 weeks post-intervention. Anthropometric measurements and food recalls were collected at the beginning, weeks 6 and 12. Zinc supplementation significantly elevated serum zinc concentrations in the treatment group (p < 0.001). Treatment also reduced alanine aminotransferase and γ-glutamyl transpeptidase enzymes in the treatment group (p < 0.05). Waist circumference was also significantly lowered in the zinc group (p < 0.05). Liver steatosis and fatty liver index changes were not significant between the groups. Overall, beneficial effects of zinc supplementation were shown on serum levels of zinc and liver enzymes in overweight/obese NAFLD patients.

Quantitative Evaluation of Hepatic Steatosis Using Normalized Local Variance in a Rat Model: Comparison with Histopathology as the Reference Standard

Objective

To evaluate the diagnostic performance of the normalized local variance (NLV) ultrasound technique in the assessment of hepatic steatosis, and to identify the factors that influence the NLV value using histopathological examination as the reference standard.

Materials and Methods

Forty male Sprague-Dawley rats were fed a methionine-choline-deficient diet for variable periods (0, 2, 4, 6, 8, 10, or 12 days or 2, 3, or 4 weeks; four rats per group). At the end of each diet duration, magnetic resonance spectroscopy (MRS) and NLV examination were performed. Thereafter, the rats were sacrificed and their livers were histopathologically evaluated. Receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic capability of the NLV value in the detection of varying degrees of hepatic steatosis. Univariate and multivariate linear regressions were used to determine the factors associated with the NLV value.

Results

The areas under the ROC curve for the detection of mild, moderate, and severe hepatic steatosis were 0.953, 0.896, and 0.735, respectively. The NLV value showed comparable diagnostic performance to that of MRS in the detection of ≥ mild or ≥ moderate hepatic steatosis. Multivariate linear regression analysis revealed that the degree of hepatic steatosis was the only significant factor affecting the NLV value (p < 0.001).

Conclusion

The NLV value of ultrasound demonstrated satisfactory diagnostic performance in the assessment of varying degrees of hepatic steatosis. The degree of hepatic steatosis was the only significant factor that affected the NLV value.

Multiparametric MR Index for the Diagnosis of Non-Alcoholic Steatohepatitis in Patients with Non-Alcoholic Fatty Liver Disease

Non-alcoholic steatohepatitis (NASH) is a complex disease consisting of various components including steatosis, lobular inflammation, and ballooning degeneration, with or without fibrosis. Therefore, it is difficult to diagnose NASH with only one imaging modality. This study was aimed to evaluate the feasibility of magnetic resonance imaging (MRI) for predicting NASH and to develop a non-invasive multiparametric MR index for the detection of NASH in non-alcoholic fatty liver disease (NAFLD) patients. This prospective study included 47 NAFLD patients who were scheduled to undergo or underwent ultrasound-guided liver biopsy within 2 months. Biopsy specimens were graded as NASH or non-NASH. All patients underwent non-enhanced MRI including MR spectroscopy (MRS), MR elastography (MRE), and T1 mapping. Diagnostic performances of MRS, MRE, and T1 mapping for grading steatosis, activity, and fibrosis were evaluated. A multiparametric MR index combining fat fraction (FF), liver stiffness (LS) value, and T1 relaxation time was developed using linear regression analysis. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of the newly devised MR index. Twenty NASH patients and 27 non-NASH patients were included. Using MRS, MRE, and T1 mapping, the mean areas under the curve (AUCs) for grading steatosis, fibrosis, and activity were 0.870, 0.951, and 0.664, respectively. The multiparametric MR index was determined as 0.037 × FF (%) + 1.4 × LS value (kPa) + 0.004 × T1 relaxation time (msec) −3.819. ROC curve analysis of the MR index revealed an AUC of 0.883. The cut-off value of 6 had a sensitivity of 80.0% and specificity of 85.2%. The multiparametric MR index combining FF, LS value, and T1 relaxation time showed high diagnostic performance for detecting NASH in NAFLD patients.

Utility of magnetic resonance proton density fat fraction technique in quantification of liver fat in living donors for liver transplantation

Background

Hepatic steatosis in living donors for liver transplantation causes morbidity of both donor and recipient. This study aims at evaluating magnetic resonance proton density fat fraction technique (MR PDFF) in quantitative evaluation of living donor’s hepatic steatosis compared to histopathology.

Results

The examined potential living liver donors’ liver biopsies revealed hepatic steatosis < 5% (grade 0) in 40 donors and 5–10% (grade 1) in 7 donors. MR PDFF technique with IDEAL sequence showed excellent results for prediction and quantitative evaluation of liver fat with sensitivity, specificity, and accuracy of 85.7%, 97.5%, and 95.7%, respectively, compared to histopathology (95% confidence interval 0.98–1.01). There was an excellent inter-reader agreement between both readers in estimation of MR liver fat fraction (r = 0.969 at 95% confidence interval 0.946–0.983).

Conclusion

Noninvasive hepatic MR PDFF technique with IDEAL sequence is a precise reliable technique for pre-operative quantitative assessment of hepatic steatosis in potential living liver donors.

Acoustic Radiation Force Impulse and Conventional Ultrasound in the Prediction of Cirrhosis Complicating Fatty Liver: Does Body Mass Index Independently Alter the Results?

We investigated whether ultrasound (US) could quantify steatosis and fibrosis in non-alcoholic fatty liver disease (NAFLD). Estimates of fat by gray-scale, hepatorenal index (HRI) and fibrosis by acoustic radiation force impulse (ARFI) were made using the interquartile range (IQR)/median for ARFI quality. Biopsy was the gold standard. US fat assessment correlated with histologic grade and predicted steatosis. HRI predicted steatosis but did not improve accuracy. ARFI of good quality was highly sensitive toward severe fibrosis. The median ARFI value depended linearly on body mass index (BMI). Poor quality ARFI data had higher histologic steatosis, leading to higher mean steatosis grades in rejected data (p = 0.018). The ARFI quality cut with IQR/median >0.15 or >0.3 excluded many more patients with severe steatosis versus normal, influenced by increasing BMI. By combining the baseline US with ARFI, patients can be concurrently diagnosed for steatosis and fibrosis, two of the key pathologies of NAFLD and non-alcoholic steatohepatitis (NASH). However, severe steatosis and high BMI may falsely alter ARFI results.

Ultrasound-based techniques for the diagnosis of liver steatosis

Non-alcoholic fatty liver disease (NAFLD) is the leading cause of diffuse liver disease. An accurate estimate of the fat in the liver is important in the diagnostic work-up of patients with NAFLD because the degree of liver steatosis is linked to the metabolic syndrome and the cardiovascular risk. Ultrasound (US) B-mode imaging allows to subjectively estimate the fatty infiltration in the liver; however, it has a low performance for the detection of mild steatosis. Quantitative US is based on the analysis of the radiofrequency echoes detected by an US system, and it allows to calculate a backscatter coefficient or an attenuation coefficient or the sound speed. The estimation of the backscatter coefficient is rather cumbersome and requires the use of a phantom for addressing all sources of variability. Controlled attenuation parameter (CAP) available on the FibroScan^® system (Echosens, France) measures the attenuation of the US beam. CAP is accurate in grading fatty infiltration-even though there is an overlap between consecutive grade of liver steatosis-and the values are not influenced by liver fibrosis. Several US manufacturers are developing or have already developed software for quantifying the attenuation of the US beam. Preliminary results show that proprietary technologies implemented in US systems seem more accurate than CAP for grading liver steatosis. Another available method for quantifying liver steatosis is based on the computation of the sound speed and the initial results appear promising.

Non-invasive monitoring of hepatic steatosis via acoustic structure quantification of ultrasonography with MR spectroscopy as the reference standard

Purpose

The purpose of this study was to prospectively evaluate whether monitoring hepatic steatosis by ultrasonography with acoustic structure quantification (ASQ) is feasible, using magnetic resonance spectroscopy (MRS) as the reference standard.

Methods

Thirty-six patients with suspected fatty liver disease underwent both untrasonography with ASQ and MRS on the same day. After a mean follow-up period of 11.4±2.5 months, follow-up ultrasonography with ASQ and MRS were performed on 27 patients to evaluate whether hepatic steatosis had improved. The focal disturbance (FD) ratio, as calculated using ASQ, and the hepatic fat fraction (HFF), estimated by MRS, were obtained at both initial and follow-up examinations. Pearson correlation coefficients were calculated to assess the correlations between ordinal values.

Results

The FD ratio showed a strong, negative linear correlation with the HFF after logarithmic transformation of both variables from the initial examinations of 36 patients (ρ=-0.888, P<0.001) and the follow-up examinations of 27 patients (ρ=-0.920, P<0.001). There was also a significant, negative linear correlation between the change in the logarithm of the FD ratio and the change in the logarithm of the HFF by MRS over the follow-up period (ρ=-0.645, P<0.001). In 16 patients with an increased FD ratio on follow-up, the HFF on follow-up MRS significantly decreased, and high-density lipoprotein levels significantly increased, whereas low-density lipoprotein levels tended to decrease.

Conclusion

The FD ratio was significantly correlated with the HFF at both the initial and follow-up examinations, and there was also a significant correlation between changes in the FD ratio and changes in the HFF over the follow-up period.

Steato-Score: Non-Invasive Quantitative Assessment of Liver Fat by Ultrasound Imaging

Non-alcoholic fatty liver disease is becoming a global epidemic. The aim of this study was to develop a system for assessing liver fat content based on ultrasound images. Magnetic resonance spectroscopy measurements were obtained in 61 patients and the controlled attenuation parameter in 54. Ultrasound images were acquired for all 115 participants and used to calculate the hepatic/renal ratio, hepatic/portal vein ratio, attenuation rate, diaphragm visualization and portal vein wall visualization. The Steato-score was obtained by combining these five parameters. Magnetic resonance spectroscopy measurements were significantly correlated with hepatic/renal ratio, hepatic/portal vein ratio, attenuation rate, diaphragm visualization and portal vein wall visualization; Steato-score was dependent on hepatic/renal ratio, attenuation rate and diaphragm visualization. Area under the receiver operating characteristic curve was equal to 0.98, with 89% sensitivity and 94% specificity. Controlled attenuation parameter values were significantly correlated with hepatic/renal ratio, attenuation rate, diaphragm visualization and Steato-score; the area under the curve was 0.79. This system could be a valid alternative as a non-invasive, simple and inexpensive assessment of intrahepatic fat.

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.

Imaging evaluation of non-alcoholic fatty liver disease: focused on quantification

Non-alcoholic fatty liver disease (NAFLD) has been an emerging major health problem, and the most common cause of chronic liver disease in Western countries. Traditionally, liver biopsy has been gold standard method for quantification of hepatic steatosis. However, its invasive nature with potential complication as well as measurement variability are major problem. Thus, various imaging studies have been used for evaluation of hepatic steatosis. Ultrasonography provides fairly good accuracy to detect moderate-to-severe degree hepatic steatosis, but limited accuracy for mild steatosis. Operator-dependency and subjective/qualitative nature of examination are another major drawbacks of ultrasonography. Computed tomography can be considered as an unsuitable imaging modality for evaluation of NAFLD due to potential risk of radiation exposure and limited accuracy in detecting mild steatosis. Both magnetic resonance spectroscopy and magnetic resonance imaging using chemical shift technique provide highly accurate and reproducible diagnostic performance for evaluating NAFLD, and therefore, have been used in many clinical trials as a non-invasive reference of standard method.

Body frame size in school children is related to the amount of adipose tissue in different depots but not to adipose distribution

OBJECTIVES

The main aim of this study was to test the hypothesis that body frame size is related to the amount of fat in different adipose tissue depots and to fat distribution in schoolchildren.

METHODS

Children aged between 5 and 10 years were included in this cross-sectional study (n = 565). Body frame size, adiposity markers (anthropometric, skinfolds thickness, and ultrasound measures), and fat distribution indices were analyzed. Correlation coefficients adjusted by reliability were estimated and analyzed by sex; the significance of the difference between two correlation coefficients was assessed using the Fisher z-transformation.

RESULTS

The sample included primarily urban children; 58.6% were normal weight, 16.1% overweight, 19.6% obese, and the rest were underweight. Markers of subcutaneous adiposity, fat mass and fat-free mass, and preperitoneal adiposity showed higher and significant correlations with the sum of the biacromial + bitrochanteric diameter than with the elbow diameter, regardless of sex. The fat distribution conicity index presented significant but weak correlations; and visceral adipose tissue, hepatic steatosis, and the waist-for-hip ratio were not significantly correlated with body frame size measures.

CONCLUSIONS

Body frame size in school children was related to the amount of adipose tissue in different depots, but not adipose distribution. More studies are needed to confirm this relationship and its importance to predict changes in visceral fat deposition during growth.

Noninvasive assessment of liver steatosis in children: the clinical value of controlled attenuation parameter

Background

To assess the clinical validity of controlled attenuation parameter (CAP) in the diagnosis of hepatic steatosis in a series of overweight or obese children by using the imperfect gold standard methodology.

Methods

Consecutive children referred to our institution for auxological evaluation or obesity or minor elective surgery were prospectively enrolled. Anthropometric and biochemical parameters were recorded. Ultrasound (US) assessment of steatosis was carried out using ultrasound systems. CAP was obtained with the FibroScan 502 Touch device (Echosens, Paris, France). Pearson’s or Spearman’s rank correlation coefficient were used to test the association between two study variables. Optimal cutoff of CAP for detecting steatosis was 249 dB/m. The diagnostic performance of dichotomized CAP, US, body mass indexes (BMI), fatty liver index (FLI) and hepatic steatosis index (HSI) was analyzed using the imperfect gold standard methodology.

Results

Three hundred five pediatric patients were enrolled. The data of both US and CAP were available for 289 children. Steatosis was detected in 50/289 (17.3%) children by US and in 77/289 (26.6%) by CAP. A moderate to good correlation was detected between CAP and BMI (r = 0.53), FLI (r = 0.55) and HSI (r = 0.56). In obese children a moderate to good correlation between CAP and insulin levels (r = 0.54) and HOMA-IR (r = 0.54) was also found. Dichotomized CAP showed a performance of 0.70 (sensitivity, 0.72 [0.64–0.79]; specificity, 0.98 [0.97–0.98], which was better than that of US (performance, 0.37; sensitivity, 0.46 [0.42–0.50]; specificity, 0.91 [0.89–0.92]), BMI (performance, 0.22; sensitivity, 0.75 [0.73–0.77]; specificity, 0.57 [0.55–0.60]) and FLI or HSI.

Conclusions

For the evaluation of liver steatosis in children CAP performs better than US, which is the most widely used imaging technique for screening patients with a suspicion of liver steatosis. A cutoff value of CAP of 249 dB/m rules in liver steatosis with a very high specificity.

A Pilot Comparative Study of Quantitative Ultrasound, Conventional Ultrasound, and MRI for Predicting Histology-Determined Steatosis Grade in Adult Nonalcoholic Fatty Liver Disease

OBJECTIVE

The purpose of this study is to explore the diagnostic performance of two investigational quantitative ultrasound (QUS) parameters, attenuation coefficient and backscatter coefficient, in comparison with conventional ultrasound (CUS) and MRI-estimated proton density fat fraction (PDFF) for predicting histology-confirmed steatosis grade in adults with nonalcoholic fatty liver disease (NAFLD).

SUBJECTS AND METHODS

In this prospectively designed pilot study, 61 adults with histology-confirmed NAFLD were enrolled from September 2012 to February 2014. Subjects underwent QUS, CUS, and MRI examinations within 100 days of clinical-care liver biopsy. QUS parameters (attenuation coefficient and backscatter coefficient) were estimated using a reference phantom technique by two analysts independently. Three-point ordinal CUS scores intended to predict steatosis grade (1, 2, or 3) were generated independently by two radiologists on the basis of QUS features. PDFF was estimated using an advanced chemical shift-based MRI technique. Using histologic examination as the reference standard, ROC analysis was performed. Optimal attenuation coefficient, backscatter coefficient, and PDFF cutoff thresholds were identified, and the accuracy of attenuation coefficient, backscatter coefficient, PDFF, and CUS to predict steatosis grade was determined. Interobserver agreement for attenuation coefficient, backscatter coefficient, and CUS was analyzed.

RESULTS

CUS had 51.7% grading accuracy. The raw and cross-validated steatosis grading accuracies were 61.7% and 55.0%, respectively, for attenuation coefficient, 68.3% and 68.3% for backscatter coefficient, and 76.7% and 71.3% for MRI-estimated PDFF. Interobserver agreements were 53.3% for CUS (κ = 0.61), 90.0% for attenuation coefficient (κ = 0.87), and 71.7% for backscatter coefficient (κ = 0.82) (p < 0.0001 for all).

CONCLUSION

Preliminary observations suggest that QUS parameters may be more accurate and provide higher interobserver agreement than CUS for predicting hepatic steatosis grade in patients with NAFLD.

Management of Nonalcoholic Fatty Liver Disease in Patients With Type 2 Diabetes: A Call to Action

Traditionally a disease of hepatologists, nonalcoholic fatty liver disease (NAFLD) has recently become a major concern for a broad spectrum of health care providers. Endocrinologists and those caring for patients with type 2 diabetes mellitus (T2DM) are at center stage, as T2DM appears to worsen the course of NAFLD and the liver disease makes diabetes management more challenging. However, the nature of this relationship remains incompletely understood. Although the increasing prevalence of NAFLD is frequently attributed to the epidemic of obesity and is often oversimplified as the "hepatic manifestation of the metabolic syndrome," it is a much more complex disease process that may also be observed in nonobese individuals and in patients without clinical manifestations of the metabolic syndrome. It carries both metabolic and liver-specific complications that make its approach unique among medical conditions. Diabetes appears to promote the development of nonalcoholic steatohepatitis (NASH), the more severe form of the disease, and increases the risk of cirrhosis and hepatocellular carcinoma. Patients and physicians face many uncertainties, including fragmented information on the natural history of the disease, challenges in the diagnosis of NASH, and few pharmacological agents with proven efficacy. However, recent advances in diagnosis and treatment, combined with the risk of serious consequences from inaction, call for health care providers to be more proactive in the management of patients with T2DM and NASH.

Focal hepatic solid lesions incidentally detected on initial ultrasonography in 542 asymptomatic patients

PURPOSE

The purpose of this study is to evaluate the clinical significance of focal hepatic solid lesions incidentally detected on initial ultrasonography in asymptomatic patients.

METHODS

From January 2009 to December 2009, 2670 initial ultrasonographies were performed in asymptomatic population. Of these 2670 initial examinations, 681 focal hepatic solid lesions in 542 patients (mean 39.4 years, range 23-73 years) were detected. Clinical information, ultrasonography features, and the outcome of these lesions were analyzed.

RESULTS

Six hundred and seventy four lesions (99.0%) in 539 patients (99.4%) were benign, while seven lesions (1.0%) in three patients (0.6%) proved to be malignant. Risk factors significantly associated with malignant focal hepatic solid lesions were known history of malignancy, history of hepatitis, a positive result for the hepatitis B surface antigen, and abnormally elevated tumor markers. No malignancy was identified in patients without any one of these four risk factors. Ultrasonographic features of internal heterogeneous echotexture with peripheral hypoechoic rim showed significant associations with malignancy.

CONCLUSIONS

Focal hepatic solid lesions incidentally detected on initial ultrasonography were rarely malignant, especially in patients without these risk factors. Therefore, the knowledge of these risk factors and US features is important in order to make a differential diagnosis between benign and malignant focal hepatic lesions.

Assessment of Liver Perfusion by IntraVoxel Incoherent Motion (IVIM) Magnetic Resonance-Diffusion-Weighted Imaging: Correlation With Phase-Contrast Portal Venous Flow Measurements

OBJECTIVES

To prospectively verify, in vivo, Le Bihan's model of signal decay in magnetic resonance/diffusion-weighted imaging (intravoxel incoherent motion) in healthy liver parenchyma.

METHODS

Informed consent and institutional board approval were obtained. To measure both underfasting and postprandial conditions, apparent, slow, and fast diffusion (D*) coefficients and perfusion fraction of liver parenchyma, 40 healthy volunteers (19 women and 21 men) underwent a 3.0-T magnetic resonance imaging examination, including portal venous flow measurements by a 2-dimensional phase-contrast sequence, and multi-b diffusion-weighted imaging acquired before and 30 minutes after a 600-Kcal meal. Parameters were measured by fitting procedure with regions of interest drawn on the right liver lobe. Paired-sample t test was performed to search for any statistically significant difference between preprandial and postprandial values of each parameter and of portal flow. Pearson correlation coefficients were calculated to evaluate the relationship between portal flow increase and diffusion-weighted imaging parameter changes in postprandial conditions. Interobserver agreement for measurement of the intravoxel incoherent motion parameters was determined, both for preprandial and postprandial values.

RESULTS

Mean increase in postprandial portal flow was 98% (P < 0.0009). The t test did not show any statistically significant difference between the preprandial and postprandial values for apparent, slow diffusion coefficients and perfusion fraction (P ≥ 0.05), whereas a statistically significant postprandial increase (P < 0.01) of D* was detected. Correlation with portal venous flow increase at Pearson test was statistically significant for D* (P = 0.04) and nonsignificant for the other parameters. All the parameters showed wide variability, with a higher percent coefficient of variation for D*. Interobserver agreement was always greater than 0.70.

CONCLUSIONS

This study verifies Le Bihan's theory, confirming that in the liver, D* is influenced by perfusional changes related to portal venous flow.

Computerized analysis of calcification of thyroid nodules as visualized by ultrasonography

OBJECTIVE

The purpose of this study is to quantify computerized calcification features from ultrasonography (US) images of thyroid nodules in order to determine the ability to differentiate between malignant and benign thyroid nodules.

METHODS

We designed and implemented a computerized analysis scheme to quantitatively analyze the US features of the calcified thyroid nodules from 99 pathologically determined calcified thyroid nodules. Univariate analysis was used to identify features that were significantly associated with tumor malignancy, and neural-network analysis was performed to classify tumors as benign or malignant. The diagnostic performance of the neural network was evaluated using receiver operating characteristic (ROC) analysis, where in the area under the ROC curve (Az) summarized the diagnostic performance of specific calcification features.

RESULTS

The performance values for each calcification feature were as follows: ratio of calcification distance=0.80, number of calcifications=0.68, skewness=0.82, and maximum intensity=0.75. The combined value of the four features was 0.84.With a threshold of 0.64, the Az value of calcification features was 0.83 with a sensitivity of 83.0%, specificity of 82.4%, and accuracy of 82.8%.

CONCLUSIONS

These results support the clinical feasibility of using computerized analysis of calcification features from thyroid US for differentiating between malignant and benign nodules.

Thyroid hormone levels in obese children and adolescents with non-alcoholic fatty liver disease

OBJECTIVE

We aimed to determine the association of thyroid functions with the components of metabolic syndrome (MS) and non-alcoholic fatty liver disease (NAFLD) in pediatric obese patients.

METHODS

The study included 109 obese children (aged 9-15 years) and a control group of 44 healthy age and gender-matched children of normal weight. NAFLD was diagnosed by conventional ultrasound examination. We assessed the anthropometric data and serum biochemical parameters including lipid profile, alanine aminotransferase (ALT), fasting glucose and insulin levels and thyroid stimulating hormone (TSH), free thyroxine (fT4) and free triiodothyronine (fT3) levels. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated as a measure of IR.

RESULTS

The mean age and gender distributions in the groups were similar (p=0.23). The mean body mass index (BMI) z-scores of obese children with grade 2-3 NAFLD were significantly higher than those of the obese children without hepatic steatosis (p<0.001). Mean ALT, triglyceride (TG) and LDL cholesterol increased and HDL-cholesterol significantly decreased as the hepatic steatosis increased (p<0.05). HOMA-IR levels in obese subjects with grade 2-3 NAFLD were significantly higher than those in both obese children without NAFLD and grade 1 NADFL (p=0.05 and 0.001, respectively). In the obese subjects, TSH levels were increased significantly as the degree of steatosis increased (p=0.04) but fT3 and fT4 levels were not different. In correlation analysis, TSH was significantly correlated with ALT, BMI SDS and the degree of steatosis.

CONCLUSIONS

Obese children demonstrate an increase in TSH levels as the degree of steatosis increased.

Hepatic steatosis in living liver donor candidates: preoperative assessment by using breath-hold triple-echo MR imaging and 1H MR spectroscopy

PURPOSE

To evaluate the diagnostic performance of both breath-hold T2*-corrected triple-echo spoiled gradient-echo water-fat separation magnetic resonance (MR) imaging (triple-echo imaging) and high-speed T2-corrected multiecho hydrogen 1 ((1)H) MR spectroscopy in the assessment of macrovesicular hepatic steatosis in living liver donor candidates by using histologic assessment as a reference standard.

MATERIALS AND METHODS

The institutional review board approved this retrospective study with waiver of the need to obtain informed consent. One hundred eighty-two liver donor candidates who had undergone preoperative triple-echo imaging and single-voxel (3 × 3 × 3 cm) MR spectroscopy performed with a 3.0-T imaging unit and who had also undergone histologic evaluation of macrovesicular steatosis were included in this study. In part 1 of the study (n = 84), the Pearson correlation coefficient was calculated. Receiver operating characteristic (ROC) curve analysis was performed to detect substantial (≥10%) macrovesicular steatosis. In part 2 of the study, with a different patient group (n = 98), diagnostic performance was evaluated by using the diagnostic cutoff values determined in part 1 of the study.

RESULTS

The correlation coefficients of triple-echo MR imaging and MR spectroscopy with macrovesicular steatosis were 0.886 and 0.887, respectively. The areas under the ROC curve for detection of substantial macrovesicular steatosis were 0.959 and 0.988, with cutoff values of 4.93% and 5.79%, respectively, and without a significant difference (P = .328). In the part 2 study group, sensitivity and specificity were 90.9% (10 of 11) and 86.2% (75 of 87) for triple-echo MR imaging and 90.9% (10 of 11) and 86.2% (75 of 87) for MR spectroscopy, respectively.

CONCLUSION

Either breath-hold triple-echo MR imaging or MR spectroscopy can be used to detect substantial macrovesicular steatosis in living liver donor candidates. In the future, this may allow selective biopsy in candidates who are expected to have substantial macrovesicular steatosis on the basis of MR-based hepatic fat fraction.

The relationship between pediatric nonalcoholic fatty liver disease and cardiovascular risk factors and increased risk of atherosclerosis in obese children

To investigate the relationship between nonalcoholic fatty liver disease and cardiovascular risk factors and increased risk of atherosclerosis in obese children. The study included 80 consecutive obese children who were stratified into group 1 [ultrasonographically diagnosed with NAFLD (n = 50)] and group 2 [not diagnosed with NAFLD (n = 30)]. The control group included 30 healthy children. The groups were compared in terms of clinical cardiovascular risk factors and carotid intimal medial thickness (CIMT) (as a marker of atherosclerosis) measured using B-mode ultrasound. Mean body mass index (BMI) and blood pressure (BP), as well as the frequency of dyslipidemia, metabolic syndrome (MetS), and insulin resistance (IR), were similar in groups 1 and 2. Mean BMI and triglyceride (TG) levels, and the frequency of IR and MetS, increased significantly as the grade of steatosis increased. Mean CIMT in group 1 was significantly greater than that in the control group (P < 0.01). There was a positive correlation between CIMT and age, BP, and BMI in groups 1 and 2. In addition, CIMT was correlated with TG, low high-density lipoprotein (HDL) cholesterol, MetS, and IR only in group 1. Linear regression analysis between CIMT and age, BP, BMI, TG level, HDL cholesterol level, IR, MetS, and grade of steatosis yielded a significant difference only for grade of steatosis. Cardiovascular risk factors are more impressive and CIMT was significantly higher in group 1 than in group 2 and the control group, indicating that they are associated with greater risk of atherosclerosis and future adverse cardiovascular events.

Sonographic hepatorenal ratio: a noninvasive method to diagnose nonalcoholic steatosis

PURPOSE

To evaluate the accuracy of the sonographic hepatorenal ratio (HRR) in the diagnosis and grading of nonalcoholic steatosis, using biopsy as the reference.

METHODS

Ultrasound (US) and liver biopsy were performed in 42 patients with nonalcoholic fatty liver disease. Forty healthy volunteers without steatosis at US and without risk factors for nonalcoholic fatty liver disease were also studied. The HRR was obtained by dividing the mean brightness level of region-of-interest pixels in hepatic parenchyma by that in renal parenchyma. Needle biopsy samples (hematoxylin-eosin stained) were classified as mild (5-33% fatty infiltration), moderate (>33-66%), or severe (>66%) steatosis. Spearman coefficient was used to evaluate the correlation between HRR and steatosis grade, analysis of variance for differences between subgroups, and receiver operating characteristic curve analysis for sensitivity and specificity.

RESULTS

Significant correlation was found between HRR and histologic steatosis (r = 0.80, p < 0.01). The HRR cutoff for predicting steatosis was ≥1.24 (sensitivity, 92.7%; specificity, 92.5%). The mean ± SD HRRs in controls and steatosis subgroups were control 1.09 ± 0.13, mild 1.46 ± 0.24, moderate 1.52 ± 0.27, severe 2.04 ± 0.3 and were significantly different from each other except between mild and moderate steatosis subgroups.

CONCLUSIONS

The HRR is a noninvasive, objective, and simple method that could be used to diagnose and grade hepatic steatosis.

Quantification of hepatic macrosteatosis in living, related liver donors using T1-independent, T2*-corrected chemical shift MRI

PURPOSE

To evaluate the diagnostic implications of the iterative decomposition of water and fat using echo-asymmetry and the least-squares estimation (IDEAL) technique to detect hepatic steatosis (HS) in potential liver donors using histopathology as the reference standard.

MATERIALS AND METHODS

Forty-nine potential liver donors (32 male, 17 female; mean age, 31.7 years) were included. All patients were imaged using the in- and out-of-phase (IOP) gradient-echo (GRE) and IDEAL techniques on a 1.5 T MR scanner. To estimate the hepatic fat fraction (FF), two reviewers performed regions-of-interest measurement in 15 areas of the liver seen on the IOP images and on the IDEAL-FF images. The magnetic resonance imaging (MRI) and pathology values of macrosteatosis were correlated using the Pearson correlation coefficient. We analyzed the diagnostic performance of IOP imaging and IDEAL for detecting HS.

RESULTS

The results of the hepatic-FF estimated on IDEAL were well correlated with the histologic degree of macrosteatosis (γ = 0.902, P < 0.001). IDEAL showed 100% sensitivity and 91% specificity for detecting HS, and IOP imaging showed 87.5% sensitivity and 97% specificity, respectively.

CONCLUSION

IDEAL is a useful tool for the preoperative diagnosis of HS in potential living liver donors; it can also help to avoid unnecessary biopsies in these patients.

Predicting the fidelity of JPEG2000 compressed CT images using DICOM header information

PURPOSE

To propose multiple logistic regression (MLR) and artificial neural network (ANN) models constructed using digital imaging and communications in medicine (DICOM) header information in predicting the fidelity of Joint Photographic Experts Group (JPEG) 2000 compressed abdomen computed tomography (CT) images.

METHODS

Our institutional review board approved this study and waived informed patient consent. Using a JPEG2000 algorithm, 360 abdomen CT images were compressed reversibly (n = 48, as negative control) or irreversibly (n = 312) to one of different compression ratios (CRs) ranging from 4:1 to 10:1. Five radiologists independently determined whether the original and compressed images were distinguishable or indistinguishable. The 312 irreversibly compressed images were divided randomly into training (n = 156) and testing (n = 156) sets. The MLR and ANN models were constructed regarding the DICOM header information as independent variables and the pooled radiologists' responses as dependent variable. As independent variables, we selected the CR (DICOM tag number: 0028, 2112), effective tube current-time product (0018, 9332), section thickness (0018, 0050), and field of view (0018, 0090) among the DICOM tags. Using the training set, an optimal subset of independent variables was determined by backward stepwise selection in a four-fold cross-validation scheme. The MLR and ANN models were constructed with the determined independent variables using the training set. The models were then evaluated on the testing set by using receiver-operating-characteristic (ROC) analysis regarding the radiologists' pooled responses as the reference standard and by measuring Spearman rank correlation between the model prediction and the number of radiologists who rated the two images as distinguishable.

RESULTS

The CR and section thickness were determined as the optimal independent variables. The areas under the ROC curve for the MLR and ANN predictions were 0.91 (95% CI; 0.86, 0.95) and 0.92 (0.87, 0.96), respectively. The correlation coefficients of the MLR and ANN predictions with the number of radiologists who responded as distinguishable were 0.76 (0.69, 0.82, p < 0.001) and 0.78 (0.71, 0.83, p < 0.001), respectively.

CONCLUSIONS

The MLR and ANN models constructed using the DICOM header information offer promise in predicting the fidelity of JPEG2000 compressed abdomen CT images.

Feasibility and accuracy of dual-source dual-energy CT for noninvasive determination of hepatic iron accumulation

PURPOSE

To retrospectively assess feasibility of dual-source dual-energy (DSDE) computed tomography (CT) for evaluation of hepatic iron accumulation in a liver phantom and liver transplantation candidates and to compare its accuracy with that of 3-T magnetic resonance (MR) imaging.

MATERIALS AND METHODS

This study was approved by the institutional review board; informed consent was waived. A liver agar phantom containing six tubes of iron (concentrations, 100-5000 mg of iron per 100 mL of solution) was scanned at 80 and 140 kVp with both DSDE mode and single-source dual-energy (SSDE) CT with sequential scanning mode. Difference of averaged attenuation between 80 and 140 kVp at CT (ΔH) was measured and correlated with iron concentration. Thirty-two liver transplant recipients and 55 donors who underwent DSDE CT at 80 and 140 kVp were included. Twenty-three underwent 3-T liver MR with dual-echo in-phase and opposed-phase T1-weighted and spin-echo T2-weighted imaging. Hepatic ΔH was measured at CT. On T1- and T2-weighted MR images, iron indexes were calculated. Degree of iron accumulation and macrosteatosis were determined at histologic examination (reference). Diagnostic performance of ΔH at CT and iron indexes at MR for diagnosing clinically important iron accumulation was evaluated (receiver operating characteristic [ROC] analysis).

RESULTS

For phantom study, ΔH obtained from both DSDE mode and SSDE CT with sequential scanning mode was correlated with iron concentration (correlation coefficient, 1.00 and 0.943, respectively; P = .173). ΔH (13.53) in 10 patients with clinically important (≥ 10%) iron accumulation was significantly higher than that (7.39) in 77 patients with normal or mild iron deposition (P < .001). ΔH was significantly correlated with degree of iron accumulation (correlation coefficient, 0.430; P < .001) but not with degree of hepatic macrosteatosis (P = .216). Area under the ROC curve for diagnosing clinically important iron accumulation was 0.881 and 0.897 with CT and MR, respectively (P = .851).

CONCLUSION

DSDE CT is accurate for diagnosing clinically important hepatic iron accumulation without confounding influence of hepatic steatosis, with diagnostic performance on par with MR.

Diagnostic accuracy and reliability of ultrasonography for the detection of fatty liver: a meta-analysis

Ultrasonography is a widely accessible imaging technique for the detection of fatty liver, but the reported accuracy and reliability have been inconsistent across studies. We aimed to perform a systematic review and meta-analysis of the diagnostic accuracy and reliability of ultrasonography for the detection of fatty liver. We used MEDLINE and Embase from October 1967 to March 2010. Studies that provided cross-tabulations of ultrasonography versus histology or standard imaging techniques, or that provided reliability data for ultrasonography, were included. Study variables were independently abstracted by three reviewers and double checked by one reviewer. Forty-nine (4720 participants) studies were included for the meta-analysis of diagnostic accuracy. The overall sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of ultrasound for the detection of moderate-severe fatty liver, compared to histology (gold standard), were 84.8% (95% confidence interval: 79.5-88.9), 93.6% (87.2-97.0), 13.3 (6.4-27.6), and 0.16 (0.12-0.22), respectively. The area under the summary receiving operating characteristics curve was 0.93 (0.91-0.95). Reliability of ultrasound for the detection of fatty liver showed kappa statistics ranging from 0.54 to 0.92 for intrarater reliability and from 0.44 to 1.00 for interrater reliability. Sensitivity and specificity of ultrasound was similar to that of other imaging techniques (i.e., computed tomography or magnetic resonance imaging). Statistical heterogeneity was present even after stratification for multiple clinically relevant characteristics.

CONCLUSION

Ultrasonography allows for reliable and accurate detection of moderate-severe fatty liver, compared to histology. Because of its low cost, safety, and accessibility, ultrasound is likely the imaging technique of choice for screening for fatty liver in clinical and population settings.

Ultrasonographic quantitative estimation of hepatic steatosis in children With NAFLD

BACKGROUND AND AIMS

The diagnostic accuracy of hepatic ultrasonography (US) for detection and grading of hepatic steatosis in children with suspected nonalcoholic fatty liver disease (NAFLD) remains poorly characterized. The aim of this study was to prospectively evaluate the clinical utility of ultrasonographic quantification of hepatic steatosis.

PATIENTS AND METHODS

Our cohort consisted of 208 consecutive pediatric patients with biopsy-proven NAFLD. Hepatic US was performed within 1 month of the liver biopsy procedure. Steatosis identified by US was scored using a 0 to 3 scale based on echogenicity and visualization of vasculature, parenchyma, and diaphragm, and compared to histological features based on Brunt's classification.

RESULTS

The median age at time of first visit was 10.8 years and 64% were boys. Sixty-nine percent had moderate to severe steatosis on histology. Ultrasonographic steatosis score (USS) had an excellent correlation with histological grade of steatosis (with a Spearman's coefficient of 0.80). The area under the receiver operating characteristic curve for ultrasonographic detection of moderate-to-severe steatosis was 0.87. The USS did not correlate significantly with inflammatory activity or fibrosis stage; however, there was significant correlation with the NAFLD activity score (NAS), albeit this was in large part the result of the strong correlation with the steatosis component of NAS. Serum alanine transaminase and aspartate transaminase were not associated with histological grade of steatosis and showed no correlation with USS.

CONCLUSIONS

Our results, which represent the largest prospective pediatric study evaluating the role of hepatic US in children with biopsy-proven NAFLD, demonstrate the utility of this technique for noninvasive diagnosis and estimation of hepatic steatosis in children.

Factors associated with hepatic steatosis in obese children and adolescents

OBJECTIVES

Obesity is associated with high prevalence of hepatic steatosis. We speculate that determinant factors of susceptibility to hepatic steatosis in obesity could differ between children and adolescents.

PATIENTS AND METHODS

Blood biochemical parameters, systemic oxidative stress markers, proinflammatory cytokines, and adipokine levels were determined in 157 obese children and adolescents. The subjects were divided into 2 groups: children and adolescents, identified as such in accordance with Tanner stage and the measured level of dehydroepiandrosterone sulphate. Steatosis was evaluated by ultrasonography in 127 subjects.

RESULTS

Steatosis prevalence was 44.8%. In the "children" group, those with hepatic steatosis presented higher levels of erythrocyte oxidised glutathione (GSSG) and resistin, lower levels of high-density lipoprotein (HDL) cholesterol, and lower enzymatic activities of erythrocyte glutathione reductase (GRd) and glutathione oxidase (GPx). In the "adolescents" group, those with hepatic steatosis presented higher values for body mass index z score (BMIz), insulin, peptide C, homeostatic model assessment index (HOMA-IR), alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglycerides, GSSG, and leptin. These subjects also presented lower values for soluble leptin receptor, GRd, and GPx. In the "children" group, the only independent factor of steatosis was a decrease in GRd activity (odds ratio [OR] 0.165, 95% CI 0.03-0.84, P = 0.030). Moreover, in the "adolescent" group, the independent factors were higher for GSSG (OR 6.8, 95% CI 1.6-28.7, P = 0.010) and HOMA-IR (OR 1.9, 95% CI 1.17-3.1, P = 0.009).

CONCLUSIONS

Factors associated with hepatic steatosis differ between obese children and adolescents. Oxidative stress is seen to be the main process in children, whereas in adolescents oxidative stress and insulin resistance are significant factors for steatosis.

The diagnostic accuracy of US, CT, MRI and 1H-MRS for the evaluation of hepatic steatosis compared with liver biopsy: a meta-analysis

Objective

To meta-analyse the diagnostic accuracy of US, CT, MRI and ¹H-MRS for the evaluation of hepatic steatosis.

Methods

From a comprehensive literature search in MEDLINE, EMBASE, CINAHL and Cochrane (up to November 2009), articles were selected that investigated the diagnostic performance imaging techniques for evaluating hepatic steatosis with histopathology as the reference standard. Cut-off values for the presence of steatosis on liver biopsy were subdivided into four groups: (1) >0, >2 and >5% steatosis; (2) >10, >15 and >20%; (3) >25, >30 and >33%; (4) >50, >60 and >66%. Per group, summary estimates for sensitivity and specificity were calculated. The natural-logarithm of the diagnostic odds ratio (lnDOR) was used as a single indicator of test performance.

Results

46 articles were included. Mean sensitivity estimates for subgroups were 73.3–90.5% (US), 46.1–72.0% (CT), 82.0–97.4% (MRI) and 72.7–88.5% (¹H-MRS). Mean specificity ranges were 69.6–85.2% (US), 88.1–94.6% (CT), 76.1–95.3% (MRI) and 92.0–95.7% (¹H-MRS). Overall performance (lnDOR) of MRI and ¹H-MRS was better than that for US and CT for all subgroups, with significant differences in groups 1 and 2.

Conclusion

MRI and ¹H-MRS can be considered techniques of choice for accurate evaluation of hepatic steatosis.

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-010-1905-5) contains supplementary material, which is available to authorized users.

The value of transabdominal ultrasound for assessment of the severity of liver steatosis as compared to liver biopsy

The purpose of our paper was to evaluate the performance of ultrasound (US) for assessment of the severity of liver steatosis as compared to a pathological examination, which is presently considered to be the gold standard, in patients that have undergone liver biopsy for various reasons. We performed echo-assisted liver biopsy in 161 patients with chronic hepatitis with the US aspect of “bright liver” with “posterior attenuation”, using modified Menghini needles. Following the US examination, the severity of liver steatosis was estimated as minimal, mild, moderate. or severe according to the Hepburn classification: absent (affecting 0% to 2% of the hepatocytes), minimal (2% to 10%), mild (10% to 30%), moderate (30% to 60%), and severe (more than 60% of the hepatocytes). The results of this study showed that the sensitivity of US for the prediction of histological steatosis of at least moderate severity was 0.64, with 0.77 specificity, 0.55 positive predictive value, and 0.94 negative predictive value. The overall accuracy was 0.75. This study showed that the transabdominal ultrasound evaluation of the fatty liver is a quite good predictor, perhaps sufficient for most purposes, for the estimation of the severity of liver steatosis in the moderate to severe range.