Ultrasound hepatic/renal ratio and hepatic attenuation rate for quantifying liver fat content

Metabolic dysfunction-associated steatotic liver disease and increased risk of atrial fibrillation in the elderly: A longitudinal cohort study

Background

Emerging evidence suggests a link between metabolic dysfunction-associated steatotic liver disease (MASLD) and cardiac arrhythmia. This study aims to investigate the potential relationship between MASLD and atrial fibrillation (AF).

Methods

This retrospective cohort study included 8511 participants (age > 65 years) without a history of cardiovascular diseases, cancer, or severe kidney dysfunction. MASLD was diagnosed using hepatic ultrasound in the presence of at least one cardiometabolic risk factor. Poisson regression models were employed to estimate the relative risk (RR) of AF, adjusting for potential confounders.

Results

Participants were categorized into MASLD (n = 3,926) and non-MASLD (n = 4,585) groups. During a mean follow-up period of 3.65 ± 1.20 years, 307 participants with MASLD developed AF, however, the number in the non-MASLD group was 144 (incidence rate 7.82 % vs. 3.14 %). After adjusting for multiple cardiovascular risk factors, MASLD was associated with increased risk of AF (RR = 1.55, 95 %, confidence interval (CI): 1.12-2.13). Positive correlations were observed between age, body mass index (BMI), systolic and diastolic blood pressure, low-density lipoprotein levels, and AF risk. Subgroup analysis revealed a stronger association between MASLD and AF in participants with BMI < 24 kg/m2 (P < 0.01).

Conclusion

This study highlights a significant association between MASLD and an increased risk of developing AF. The elevated risk in patients with MASLD may involve mechanisms extending beyond traditional cardiometabolic factors, particularly in individuals with lower BMI. Further experimental research is warranted to elucidate the underlying pathways linking MASLD and AF.

Comparing Three Ultrasound-Based Techniques for Diagnosing and Grading Hepatic Steatosis in Metabolic Dysfunction-Associated Steatotic Liver Disease

RATIONALE AND OBJECTIVES

To compare the diagnostic accuracy and grading ability of ultrasound-derived fat fraction (UDFF), controlled attenuation parameters (CAP), and hepatic/renal ratio (HRR) for hepatic steatosis in metabolic dysfunction-associated steatotic liver disease (MASLD) using magnetic resonance imaging proton density fat fraction (PDFF) as the gold standard.

METHODS

Patients suspected of having MASLD in our hospital between October 2023 and May 2024 were divided into the MASLD group and the control group. All patients underwent UDFF, CAP, and PDFF examinations. HRR was measured during routine ultrasound examination. In statistical analysis, we initially assessed the correlation between UDFF, CAP, HRR, and general characteristics of subjects with PDFF. Subsequently, receiver operating characteristic curve were employed to evaluate and compare the diagnostic performance of UDFF, CAP, and HRR for different grades of hepatic steatosis in MASLD. Their area under the curve, optimal cut-off value, sensitivity, and specificity were also determined. Finally, predictive factors determined hepatic steatosis in MASLD (PDFF≥6%) were identified through binary logistic regression analysis.

RESULTS

115 individuals were ultimately included in the MASLD group, while 102 were included in the control group. UDFF, CAP, and HRR were all positively correlated with PDFF. Among them, UDFF exhibited the strongest correlation with PDFF (ρ = 0.91). Furthermore, in the comparison of diagnostic efficacy among different grades of hepatic steatosis, UDFF outperformed CAP and HRR (p < 0.05). However, there were no statistically significant differences in AUCs between CAP and HRR across all three grades. The AUCs for UDFF in ≥S1, ≥S2, and ≥S3 were 0.99 (95% CI 0.97 to 1.00), 0.96 (95% CI 0.93 to 0.98), and 0.97 (95% CI 0.94 to 0.99), respectively. The optimal thresholds for UDFF are determined as follows: ≥ 6% for grade S1; ≥ 15% for grade S2; and ≥ 23% for grade S3. Multivariate analysis revealed that only age, UDFF, and CAP were important influencing factors for hepatic steatosis in MASLD.

CONCLUSION

The diagnostic accuracy of UDFF surpassed that of CAP and HRR in the detection and grading of hepatic steatosis in MASLD.

Ways to overcome difficulties in diagnosing non-alcoholic fatty liver disease

The purpose of the study is to evaluate the status and capabilities of modern types of diagnostics of non-alcoholic fatty liver disease as part of a meta-analysis of scientific data. Materials and methods. The literature search was carried out in electronic databases Cochrane Library, PubMed.gov, Elsevier.com, Google Scholar. The analysis of the data obtained was focused on works published between 2010 and 2023 (the bias in the form of later studies was used in isolated cases when it came to fundamental scientometric data). Results. After reviewing 693 scientific papers for duplication and inconsistency, 38 sources were selected. Conclusions. The analysis of scientific data revealed that despite the understanding of the pathogenetic causes of non-alcoholic fatty liver disease and the complexity of this disease, liver biopsy still remains the gold standard for assessing liver health. In this regard, there is a need to introduce accessible non-imaging tools and accurate biomarkers, with the help of which it will be possible not only to make an adequate diagnosis, but also to analyze new treatments for NAFLD in clinical trials.

Prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) in a middle-aged population with overweight and normal liver enzymes, and diagnostic accuracy of noninvasive proxies

The prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing at an alarming rate. Elevated liver enzymes are a primary reason to refer patients for further testing. However, liver enzymes within the normal range do not exclude the presence of MASLD. We examined the prevalence of MASLD in a middle-aged population with overweight and normal liver enzymes. In addition, we examined the accuracy of 4 sets of noninvasive proxies for MASLD. We included 1017 participants from the Netherlands epidemiology of obesity cohort study with body mass index ≥25 kg/m2 and liver enzymes (asparate aminotransferase, alanine aminotransferase, gamma-glutamyltranspeptidase) within normal range. The diagnostic accuracy of biomarker scores (fatty liver index, liver fat score [LFS], STEATO-ELSA, and hepatic steatosis index) was determined against elevated hepatic triglyceride content measured by 1proton magnetic resonance spectroscopy. Participants (mean age 56 years, 49% women), had a median body mass index of 29.6 kg/m2 and a median hepatic triglyceride content of 4.4%. MASLD was present in 42% of participants and was more common in men than women, with respectively 47% and 36% being affected. The LFS showed the highest accuracy with an area under the curve of 0.72. We identified metabolic syndrome as the prime predictor for MASLD with an odds ratio of 2.95 (95% confidence interval 2.20-3.98). The prevalence of MASLD in middle-aged men and women with overweight and liver enzymes within the normal range is over 40%. LFS showed the highest accuracy to detect MASLD, but, overall, biomarker scores performed relatively poor. The presence of metabolic syndrome was the prime predictor of MASLD.

Evaluation of Hepatic/Renal and Splenic/Renal Echointensity Ratio Using Ultrasonography in Diabetic Nephropathy

The objective of this study is to assess the hepatic/renal and splenic/renal echointensity ratios in ultrasonography in patients with and without diabetic nephropathy. This retrospective study included patients with diabetes mellitus who underwent ultrasound examinations at our hospital between January 2023 and May 2023. Ultrasound examinations were conducted using renal cortical echogenicity and corticomedullary differentiation by using B-mode ultrasonography. The hepatic/renal and splenic/renal echo intensity ratios were compared among study groups (diabetic patients with diabetic nephropathy and without nephropathy). The diabetic nephropathy group exhibited significantly higher right renal echointensity and left renal echointensity compared to the non-nephropathic group. Additionally, the splenic/renal echointensity ratio and hepatic/renal echointensity ratio were significantly lower in the diabetic nephropathy group. Urinary microalbumin levels were significantly correlated with right renal echointensity (r = 0.65, p < 0.001) and left renal echointensity (r = 0.69, p < 0.001). There was also a significant inverse correlation between the urinary albumin and splenic/renal echointensity ratio (r = -0.58, p < 0.001). Ultrasonography, specifically the assessment of hepatic/renal and splenic/renal echointensity ratios, shows promise as a noninvasive and cost-effective method for evaluating morphological changes in the kidneys in patients with diabetic nephropathy. These findings suggest that ultrasonography can be a valuable tool for monitoring the progression of diabetic nephropathy and contributing to its early detection and management.

CX08005, a Protein Tyrosine Phosphatase 1B Inhibitor, Attenuated Hepatic Lipid Accumulation and Microcirculation Dysfunction Associated with Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is one of the common metabolic diseases characterized by hepatic lipid accumulation. Insulin resistance and microcirculation dysfunction are strongly associated with NAFLD. CX08005, an inhibitor of PTP1B with the IC₅₀ of 0.75 ± 0.07 μM, has been proven to directly enhance insulin sensitivity. The present study aimed to investigate the effects of CX08005 on hepatic lipid accumulation and microcirculation dysfunction in both KKAy mice and diet-induced obesity (DIO) mice. Hepatic lipid accumulation was evaluated by hepatic triglyceride determination and B-ultrasound analysis in KKAy mice. Insulin sensitivity and blood lipids were assessed by insulin tolerance test (ITT) and triglyceride (TG)/total cholesterol (TC) contents, respectively. In addition, the hepatic microcirculation was examined in DIO mice by in vivo microscopy. The results showed that CX08005 intervention significantly reduced the TG and echo-intensity attenuation coefficient in the livers of KKAy mice. Furthermore, we found that CX08005 treatment significantly enhanced insulin sensitivity, and decreased plasma TG and/or TC contents in KKAy and DIO mice, respectively. In addition, CX08005 treatment ameliorated hepatic microcirculation dysfunction in DIO mice, as evidenced by increased RBCs velocity and shear rate of the blood flow in central veins and in the interlobular veins, as well as enhanced rate of perfused hepatic sinusoids in central vein area. Additionally, CX08005 administration decreased the adhered leukocytes both in the center veins and in the hepatic sinusoids area. Taken together, CX08005 exhibited beneficial effects on hepatic lipid accumulation and microcirculation dysfunction associated with NAFLD, which was involved with modulating insulin sensitivity and leukocyte recruitment, as well as restoration of normal microcirculatory blood flow.

Association between triglyceride-glucose index and nonalcoholic fatty liver disease in type 2 diabetes mellitus

BACKGROUND

Lipid and glucose metabolism abnormalities are associated with nonalcoholic fatty liver disease (NAFLD). The triglyceride-glucose (TyG) index is a recently developed indicator that can identify individuals at risk for NAFLD. However, the applicability of the TyG index for identifying NAFLD in patients with type 2 diabetes mellitus (T2DM) is unclear. The aim of this study was to investigate the ability of the TyG index to identify individuals at risk for NAFLD in the T2DM population.

METHODS

A total of 2280 participants with T2DM were recruited in this cross-sectional study. The TyG index was calculated, and NAFLD was diagnosed by ultrasonography. Binary logistic regression models were used to evaluate the association of the TyG index, glycemic parameters and lipid parameters with NAFLD.

RESULTS

Logistic regression analysis showed that the TyG index was significantly associated with NAFLD in subjects with T2DM, the odds ratio (OR) were 3.27 (95% confidence interval [CI], 2.03-5.27; P < 0.001) for NAFLD in the highest TyG quartile after adjustment for known confounders. In stratified analysis, an elevated TyG index were more remarkably associated with NAFLD in younger patients (< 65 years; OR, 2.35; 95% CI, 1.83-3.02; P < 0.001), females (OR, 2.69; 95% CI, 1.67-4.32; P < 0.001), patients with BMI < 25 kg/m² (OR, 2.80; 95% CI, 2.01-3.91; P < 0.0001), and with lower high-density lipoprotein cholesterol (< 1 mmol/L; OR, 2.76; 95% CI, 1.98-3.83; P < 0.001).

CONCLUSION

The TyG index is significantly associated with NAFLD and shows superior ability for identify NAFLD risk compared with other lipid and glycemic parameters in T2DM.

Triglyceride affects the association between estimated glomerular filtration rate and the onset of non-alcoholic fatty liver disease: A second analysis of a Chinese cohort study

OBJECTIVE

The role of triglyceride (TG) and estimated glomerular filtration rate (eGFR) effect modifiers on the risk of non-alcoholic fatty liver disease (NAFLD) is unknown. This study examined whether TG modifies the relationship between eGFR and incident NAFLD.

METHODS

In a Chinese hospital from January 2010 to December 2014, 15,555 non-obese subjects were collected systematically for this retrospective cohort study. The target-independent and dependent variables were eGFR measured at baseline and NAFLD appearing during follow-up. The modified variable was TG measured at baseline. The multivariate Cox proportional hazards model was used to explore eGFR and TG's association with NAFLD risk. We explored a priori interaction between eGFR and TG, and performed subgroup analyses to further assess whether the relationship between eGFR and incident NAFLD was modified by TG. We also explored the effect of TG and eGFR interaction on the risk of NAFLD.

RESULTS

The mean age was 43.09 ± 14.92 years, and 8,131 (52.27%) were males. During a median follow-up time of 35.8 months, 2,077 (13.35%) individuals developed NAFLD. In the adjusted model, eGFR was negatively associated with incident NAFLD (HR = 0.984, 95% CI: 0.982, 0.987), while TG was positively related to NAFLD (HR = 1.582, 95% CI: 1.490, 1.681). TG could modify the relationship between eGFR and incident NAFLD. A stronger association between eGFR and NAFLD could be found in the participants without hypertriglyceridemia (HTG) (HR = 0.981, 95% CI: 0.978-0.984, P for interaction = 0.0139). In contrast, the weaker association was probed in the population with HTG (HR = 0.986, 95% CI: 0.983-0.989). At the same time, we also found an interaction between eGFR and TG in influencing NAFLD risk. In participants with decreased eGFR and HTG, the risk of NAFLD was significantly increased. Further, compared to non-HTG subjects with eGFR ≥ 116.56 ml/min/1.73 m2, participants with HTG and eGFR < 82.88 ml/min/1.73 m2 had about a fourfold increase in the risk (HR = 4.852 95% CI: 3.943-5.970) of NAFLD.

CONCLUSION

eGFR and TG is independently associated with NAFLD risk. The association of eGFR with incident NAFLD is likely to be modified by TG in the Chinese non-obese population. There was an interactive effect between eGFR and TG in affecting NAFLD risk. In participants with decreased eGFR and hypertriglyceridemia, the risk of NAFLD is significantly increased.

The triglyceride glucose-body mass index: a non-invasive index that identifies non-alcoholic fatty liver disease in the general Japanese population

BACKGROUND

By identifying individuals at high risk for non-alcoholic fatty liver disease (NAFLD), interventional programs could be targeted more effectively. Some studies have demonstrated that triglyceride glucose-body mass index (TyG-BMI) showed an independent positive association with NAFLD. However, research on its diagnostic value in patients with suspected NAFLD is limited. In this study, we aimed to evaluate whether TyG-BMI was accurate in detecting NAFLD in the general Japanese population.

METHODS

A cross-sectional study of 14,280 individuals who underwent a comprehensive health examination was conducted. Standard protocols were followed to collect anthropometric measurements, lab data, and ultrasonography features. All participants were randomly stratified into the development group (n = 7118) and validation group (n = 7162). The TyG-BMI was calculated. Following this, the diagnostic value of the TyG-BMI was evaluated based on the area under the receiver-operating characteristic curve (AUROC). Two cutoff points were selected and used to rule out or rule in the NALFD, and the specificity, sensitivity, negative predictive value, and positive predictive value were explored, respectively. In order to verify the stability of the results, external verification was performed.

RESULTS

There were 1272 and 1243 NAFLD participants in the development and validation groups, respectively. The area under the ROC curve (AUC) of TyG-BMI was 0.888 (95% CI 0.876-0.896) and 0.884 (95% CI 0.875-0.894) for the training and validation group, respectively. Using the low TyG-BMI (182.2) cutoff, NAFLD could be excluded with high accuracy (negative predictive value: 96.9% in estimation and 96.9% in validation). The presence of NAFLD could effectively be determined by applying the high cutoff of TyG-BMI (224.0), as the positive predictive value of the estimation and validation groups is 70.7% and 70.1%, respectively. As a result of applying this model, 9996 (70%) of the 14,280 participants would not have undergone ultrasonography, with an accurate prediction of 9308 (93.1%). AUC was 0.874 for external validation using 183,730 Chinese non-obese participants. TyG-BMI was demonstrated to be an excellent diagnostic tool by both internal and external validation.

CONCLUSIONS

In conclusion, the present study developed and validated a simple, non-invasive, and cost-effective tool to accurately separate participants with and without NAFLD in the Japanese population, rendering ultrasonography for identifying NAFLD unnecessary in a substantial proportion of people.

Correlation between hepatorenal index and attenuation imaging for assessing hepatic steatosis

INTRODUCTION

Hepatic steatosis screening is required to assess high-risk populations, identify those for intervention, monitor response and prevent disease progression and complications. Liver biopsy and magnetic resonance imaging proton density fat fraction are current gold standards, but are limited by biopsy risk factors, patient tolerance and cost. Non-invasive, cost-effective, semi-quantitative and quantitative ultrasound assessment exists. The aim of this study was to assess the correlation between the semi-quantitative hepatorenal index (HRI) to assess hepatic steatosis using the quantitative attenuation imaging (ATI) as a reference standard, in adults with varied suspected liver pathologies.

METHODS

Data were collected prospectively between April 2019 and March 2020 at a tertiary institution on any patient >18 years referred to US assessment of suspected liver pathology. The only exclusion criteria were absent or invalid HRI or ATI measurements. Three hundred fifty eight patients were included.

RESULTS

There was a significant weak positive correlation between HRI and ATI (r = 0.351, P < 0.001) and between HRI steatosis grade (SG) and ATI SG (r = 0.329, P < 0.001), using previously established cut-off values. With ATI as the reference standard, there was no significant correlation between HRI and hepatic steatosis within steatosis grades, nor for no (SG = 0) or any (SG > 0) hepatic steatosis.

CONCLUSIONS

Our study in a typical heterogeneous clinical population suggests the semi-quantitative HRI is of limited use in hepatic steatosis imaging. As HRI is the objective measure of the subjective brightness (B)-mode assessment, this imaging feature may not be as reliable as previously thought. Quantitative ATI may be the preferred non-invasive technique for hepatic steatosis assessment.

Conventional ultrasound for diagnosis of hepatic steatosis is better than believed

BACKGROUND

Hepatic steatosis is a condition frequently encountered in clinical practice, with potential progression towards fibrosis, cirrhosis, and hepatocellular carcinoma. Detection and staging of hepatic steatosis are of most importance in nonalcoholic fatty liver disease (NAFLD), a disease with a high prevalence of more than 1 billion individuals affected. Ultrasound (US) is one of the most used noninvasive imaging techniques used in the diagnosis of hepatic steatosis. Detection of hepatic steatosis with US relies on several conventional US parameters, which will be described. US is the first-choice imaging in adults at risk for hepatic steatosis. The use of some scoring systems may add additional accuracy especially in assessing the severity of hepatic steatosis.

SUMMARY

In the presented paper, we discuss screening and risk stratification, ultrasound features for diagnosing hepatic steatosis, B-mode criteria, focal fatty patterns and Doppler features of the hepatic vessels, and the value of the different US signs for the diagnosis of liver steatosis including classifying the severity of steatosis using different US scores. Limitations of conventional B-mode and Doppler features in the evaluation of hepatic steatosis are also discussed, including those in grading and assessing the complications of steatosis, namely fibrosis and nonalcoholic steatohepatitis.

KEY MESSAGES

Ultrasound is the first-line imaging examination for the screening and follow-up of patients with liver steatosis. The use of some scoring systems may add additional accuracy in assessing the severity of steatosis. Conventional B-mode and Doppler ultrasound have limitations in grading and assessing the complications of steatosis.

Conventional and artificial intelligence-based imaging for biomarker discovery in chronic liver disease

Chronic liver diseases, resulting from chronic injuries of various causes, lead to cirrhosis with life-threatening complications including liver failure, portal hypertension, hepatocellular carcinoma. A key unmet medical need is robust non-invasive biomarkers to predict patient outcome, stratify patients for risk of disease progression and monitor response to emerging therapies. Quantitative imaging biomarkers have already been developed, for instance, liver elastography for staging fibrosis or proton density fat fraction on magnetic resonance imaging for liver steatosis. Yet, major improvements, in the field of image acquisition and analysis, are still required to be able to accurately characterize the liver parenchyma, monitor its changes and predict any pejorative evolution across disease progression. Artificial intelligence has the potential to augment the exploitation of massive multi-parametric data to extract valuable information and achieve precision medicine. Machine learning algorithms have been developed to assess non-invasively certain histological characteristics of chronic liver diseases, including fibrosis and steatosis. Although still at an early stage of development, artificial intelligence-based imaging biomarkers provide novel opportunities to predict the risk of progression from early-stage chronic liver diseases toward cirrhosis-related complications, with the ultimate perspective of precision medicine. This review provides an overview of emerging quantitative imaging techniques and the application of artificial intelligence for biomarker discovery in chronic liver disease.

General Overview About the Current Management of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease includes a wide spectrum of manifestations from simple steatosis to nonalcoholic steatohepatitis, fibrosis, and eventually cirrhosis or even hepatocellular carcinoma. This disorder is also associated with an increased cardiovascular risk, renal involvement, oncologic processes, metabolic disturbances, and an increased risk of all-cause mortality or hepatic mortality. For this reason, nonalcoholic fatty liver disease should be considered a disorder with high morbidity and mortality that must be diagnosed appropriately as soon as possible to establish adequate treatment. Noninvasive methods based on biochemical parameters should be used as a first step in the evaluation of any patient in whom this disease is suspected. However, serum/blood levels of liver enzymes are not a good indicator of liver damage and noninvasive methods, including biochemical tests and imaging, have suboptimal accuracy or are patented prototypes that show limitations in clinical practice. There are currently no drugs specifically approved for the treatment of these liver disorders, thus the most relevant intervention for nonalcoholic fatty liver disease is lifestyle modification.

Effects of Different Scan Projections on the Quantitative Ultrasound-Based Evaluation of Hepatic Steatosis

Non-alcoholic fatty liver disease (NAFLD) is becoming a global public health issue and the identification of the steatosis severity is very important for the patients' health. Ultrasound (US) images of 214 patients were acquired in two different scan views (subcostal and intercostal). A classification of the level of steatosis was made by a qualitative evaluation of the liver ultrasound images. Furthermore, an US image processing algorithm provided quantitative parameters (hepatic-renal ratio (HR) and Steato-score) designed to quantifying the fatty liver content. The aim of the study is to evaluate the differences in the assessment of hepatic steatosis acquiring and processing different US scan views. No significant differences were obtained calculating the HR and the Steato-score parameters, not even with the classification of patients on the basis of body mass index (BMI) and of different classes of steatosis severity. Significant differences between the two parameters were found only for patients with absence or mild level of steatosis. These results show that the two different scan projections do not greatly affect HR and the Steato-score assessment. Accordingly, the US-based steatosis assessment is independent from the view of the acquisitions, thus making the subcostal and intercostal scans interchangeable, especially for patients with moderate and severe steatosis.

Effects of Lipid Deposition on Viscoelastic Response in Human Hepatic Cell Line HepG2

Hepatic steatosis is associated with various liver diseases. The main pathological feature of steatosis is the excessive lipid accumulation. Ultrasound has been extensively used for the diagnosis of hepatic steatosis. However, most ultrasound-based non-invasive methods are still not accurate enough for cases with light lipid infiltration. One important reason is that the extent to which lipid infiltration may affect mechanical properties of hepatocytes remains unknown. In this work, we used atomic force microscope and in vitro dose-dependent lipid deposition model to detect the quantitative changes of mechanical properties under different degrees of steatosis in a single-cell level. The results show that hepatic cells with lipid deposition can be treated as linear viscoelastic materials with the power law creep compliance and relaxation modulus. Further analysis showed that even slight accumulation of lipid can lead to measurable decrease of stiffness and increased fluidity in liver cells. The accurate detection of viscoelastic properties of hepatocytes and the analysis methods may provide novel insights into hepatic steatosis grading, especially in the very early stage with reversible liver lesion. The application of viscoelasticity index for grading fat deposition might be a new detection indicator in future clinical diagnosis.

Relationship between Quantitative Sonographic Measurements and Serum Biochemical Parameters in Childhood Obesity

PURPOSE

We investigated the relationship between sonographic measurements of fatty liver and body mass index standard deviation score (BMI-Z score), abdominal wall fat thickness (AWFT), and serum biochemical parameters in childhood obesity.

METHODS

Anthropometric, laboratory, and ultrasonography data were obtained from 174 children with BMI-Z score >1. After the qualitative grading of hepatosteatosis (grades 0-3), the quantitative liver-kidney echogenicity ratio (LKER) was calculated using a software tool. Groups according to sex, age (AG-I to AG-III), BMI-Z score (BMG-I to BMG-III), and hepatosteatosis degree (HS-I and HS-II) were formed. The differences and distributions of the variables were statistically analyzed and compared among the groups.

RESULTS

Serum transaminase and glucose levels showed a positive correlation with LKER, whereas the HDL level showed a negative correlation. BMI-Z score and AWFT showed a positive correlation with fasting insulin level and HOMA-IR value. LKER was significantly higher in girls than in boys (p=0.008). In the AG-I group (age 3-8.9 years), the BMI-Z score was significantly higher, whereas AWFT was significantly lower than in the other age groups (p<0.001). The cutoff point of LKER for predicting grade 2 or higher steatosis (HS-II group) was determined to be 1.83. Cardiovascular disease risk was significantly higher in the HS-II group (p=0.035).

CONCLUSION

As a valuable quantitative measurement tool, LKER can be used for the sonographic screening of fatty liver. AWFT, on the basis of its correlation with fasting insulin level and HOMA-IR value, may be a useful sonographic parameter in the management of childhood obesity.

Current and Emerging Biomarkers and Imaging Modalities for Nonalcoholic Fatty Liver Disease: Clinical and Research Applications

PURPOSE

Nonalcoholic fatty liver disease (NAFLD) is a metabolic disorder that frequently coexists with obesity, metabolic syndrome, and type 2 diabetes. The NAFLD spectrum, ranging from hepatic steatosis to nonalcoholic steatohepatitis, fibrosis, and cirrhosis, can be associated with long-term hepatic (hepatic decompensation and hepatocellular carcinoma) and extrahepatic complications. Diagnosis of NAFLD requires detection of liver steatosis with exclusion of other causes of chronic liver disease. Screening for NAFLD and identification of individuals at risk of end-stage liver disease represent substantial challenges that have yet to be met. NAFLD affects up to 25% of adults, yet only a small proportion will progress beyond steatosis to develop advanced disease (steatohepatitis and fibrosis) associated with increased morbidity and mortality. Identification of this cohort has required the gold standard liver biopsy, which is both invasive and expensive. The use of serum biomarkers and noninvasive imaging techniques is an area of significant clinical relevance. This narrative review outlines current and emerging technologies for the diagnosis of NAFLD, nonalcoholic steatohepatitis, and hepatic fibrosis.

METHODS

We reviewed the literature using PubMed and reviewed national and international guidelines and conference proceedings to provide a comprehensive overview of the evidence.

FINDINGS

Significant advances have been made during the past 2 decades that have enhanced noninvasive assessment of NAFLD without the need for liver biopsy. For the detection of steatosis, abdominal ultrasonography remains the first-line investigation, although a controlled attenuation parameter using transient elastography is more sensitive. For detecting fibrosis, noninvasive serum markers of fibrosis and algorithms based on routine biochemistry are available, in addition to transient elastography. These techniques are well validated and have been incorporated into national and international screening guidelines. These approaches have facilitated more judicious use of liver biopsy but are yet to entirely replace it. Although serum biomarkers present a pragmatic and widely available screening approach for NAFLD in large population-based studies, magnetic resonance imaging techniques offer the benefit of achieving high degrees of accuracy in disease grading, tumor staging, and assessing therapeutic response.

IMPLICATIONS

This diagnostic clinical and research field is rapidly evolving; increasingly combined applications of biomarkers and transient elastography or imaging of selective (intermediate or high risk) cases are being used for clinical and research purposes. Liver biopsy remains the gold standard investigation, particularly in the context of clinical trials, but noninvasive options are emerging, using multimodality assessment, that are quicker, more tolerable, more widely available and have greater patient acceptability.

Digital image analysis of ultrasound images using machine learning to diagnose pediatric nonalcoholic fatty liver disease

PURPOSE

Prevalence of nonalcoholic fatty liver disease (NAFLD) in children is rising with the epidemic of childhood obesity. Our objective was to perform digital image analysis (DIA) of ultrasound (US) images of the liver to develop a machine learning (ML) based classification model capable of differentiating NAFLD from healthy liver tissue and compare its performance with pixel intensity-based indices.

METHODS

De-identified hepatic US images obtained as part of a cross-sectional study examining pediatric NAFLD prevalence were used to build an image database. Texture features were extracted from a representative region of interest (ROI) selected from US images of subjects with normal liver and subjects with confirmed NAFLD using ImageJ and MAZDA image analysis software. Multiple ML classification algorithms were evaluated.

RESULTS

Four-hundred eighty-four ROIs from images in 93 normal subjects and 260 ROIs from images in 39 subjects with NAFLD with 28 texture features extracted from each ROI were used to develop, train, and internally validate the model. An ensembled ML model comprising Support Vector Machine, Neural Net, and Extreme Gradient Boost algorithms was accurate in differentiating NAFLD from normal when tested in an external validation cohort of 211 ROIs from images in 42 children. The texture-based ML model was also superior in predictive accuracy to ML models developed using the intensity-based indices (hepatic-renal index and the hepatic echo-intensity attenuation index).

CONCLUSION

ML-based predictive models can accurately classify NAFLD US images from normal liver images with high accuracy using texture analysis features.

Comparison of Body Mass Index and Fat Indices in Predicting the Severity of Nonalcoholic Fatty Liver Disease Among Children Who Are Overweight and Obese

Background: Information of the relationships between body mass parameters and the severity of fatty liver is deficient in pediatric nonalcoholic fatty liver disease (NAFLD). Methods: The relationships between body mass parameters (waist circumference [WC], body mass index [BMI], and abdominal subcutaneous fat thickness [ASFT]) and the severity of fatty liver were prospectively evaluated in pediatric patients who are overweight or obese, suffering from NAFLD. Ultrasonography was performed to assess fatty liver and its severity on a three-grade scale (low-grade fatty liver [LGFL], grade 1 or 2; high-grade fatty liver [HGFL], grade 3). Results: A total of 110 subjects (55 LGFL and 55 HGFL) aged 6.2-17.9 years were included. The WC, BMI, and ASFT values were significantly higher in the HGFL group compared to those in the LGFL group (p = 0.00004, 0.01, and 0.04, respectively). WC had the greatest power to predict HGFL under receiver-operating characteristic curve analyses and was positively correlated with the severity of fatty liver in subjects aged 6-12-year old and 13-17-year old (p = 0.007, and 0.0039, respectively). ASFT showed a positive correlation with the severity of fatty liver in subjects aged 13-17-year old (p = 0.04). Conclusions: WC, BMI, and ASFT are predictive of severe NAFLD among children who are overweight and obese; particularly, WC has the most predictive accuracy. Among the parameters, WC and ASFT are predictive in specific age groups.

Comparison of sonographic hepatorenal ratio and the degree of hepatic steatosis in magnetic resonance imaging-proton density fat fraction

Objectives: Conventional ultrasonography can provide only semi-quantitative assessment of hepatic steatosis. The aim of this study was to assess sonographic hepatorenal ratio to quantify the severity of fatty liver. Methods: We performed a retrospective analysis of 179 patients with various liver diseases who underwent abdominal magnetic resonance imaging and ultrasonography on the same day. The hepatorenal ratio was calculated by the ratio between the mean echo intensity in regions of interests of the liver and regions of interests of the right renal cortex. Magnetic resonance imaging-proton density fat fraction was used as standard reference for steatosis grading. The effect of fibrosis measured by magnetic resonance elastography on the degree of correlation was also assessed. Results: The hepatorenal ratio was highly correlated with magnetic resonance imaging-proton density fat fraction (Spearman’s coefficient = 0.83) (p <0.001). High correlation of hepatorenal ratio with magnetic resonance imaging-proton density fat fraction was observed in patients with less than stage 2 fibrosis (p <0.001), whereas moderate correlation of hepatorenal ratio with magnetic resonance imaging-proton density fat fraction was found in patients with ≥ stage 2 fibrosis or higher (p <0.001). The hepatorenal ratio cutoff point for prediction of grade 1 hepatic steatosis was 1.18 with sensitivity of 90.0% and specificity of 80.0%. The hepatorenal ratio cutoff point for prediction of grade 2 and grade 3 hepatic steatosis was 1.55 and 1.60, respectively, with sensitivity greater than 90% and specificity greater than 80%. Conclusions: The hepatorenal ratio could become an effective quantitative tool for hepatic steatosis alternative to magnetic resonance imaging-proton density fat fraction. Application should be careful in the group of patients with stage 2 liver fibrosis or higher.

Portable Ultrasonography to Assess Adult Hepatosteatosis in Rural Ecuador

CONTEXT

Hepatosteatosis (HS) is prevalent worldwide and can be measured via ultrasonographic (US) hepatic-renal (H/R) echo-intensity ratio.

OBJECTIVE

To examine the incidence of HS in rural communities of the Ecuadorian Chimborazo region and to validate portable US as an effective method of disease screening in rural settings.

METHODS

Sagittal right liver/kidney B-mode US was performed in individuals from 4 villages using a portable US scanner equipped with a 3.5-MHz curvilinear probe. National Institutes of Health ImageJ software was used to computerize tissue echogenicity in both renal cortex and hepatic parenchyma offline. Regions of interest of 900 pixels were used for measuring pixel intensity of the right renal cortex and hepatic parenchyma when calculating the H/R ratio. The difference in pixel intensity between liver parenchyma and renal cortex was analyzed using an unpaired t test. The intraclass correlation coefficient was used to test intra- and interobserver reliability for computerizing the H/R ratio.

RESULTS

Forty patients were enrolled in the study (32 women and 8 men; mean age, 40 years). The mean (SD) H/R ratio of study patients was 3.61 (2.32), moderately higher than normal (normal, H/R <1.5). A significant difference was found in mean (SD) pixel value between hepatic parenchyma and renal cortex (52.82 [15.34] vs 19.93 [10.39]; P<.001). Thirty-four patients (85%) had an H/R ratio greater than 1.5. The intra- and interobserver reliability of computerizing H/R ratio was excellent (r=0.940; P<.01).

CONCLUSION

These findings suggest that HS is moderately present in persons in remote communities of Ecuador. The mean H/R ratio was greater than that in the diagnostic criteria for the disease. Portable US imaging may benefit these communities as an efficient method for the HS screening and diagnosis in rural areas.

Advances in ultrasound elastography for nonalcoholic fatty liver disease

The prevalence of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) has increased rapidly worldwide, making NAFLD/NASH an important global health problem from both a medical and socioeconomic standpoint. NAFLD is also regarded as a liver component of metabolic syndrome and is reported to be associated with the risk factors for metabolic syndrome. It has been suggested that NAFLD/NASH be recognized both as a liver-specific disease and as an early mediator of systemic diseases. Liver biopsy is recommended as the gold standard method for the diagnosis of NASH and for the staging of liver fibrosis in patients with NAFLD. However, because of its high cost, high risk, and high weightage as a healthcare resource, invasive liver biopsy is a poorly suited diagnostic test for such a highly prevalent condition. Therefore, the development of reliable noninvasive methods for the assessment of liver fibrosis has been sought to estimate the risk of progression of NASH to cirrhosis, estimate the risk of cardiovascular events, aid in the surveillance for HCC, and guide therapy in patients with NAFLD/NASH. In this review, we highlight the principles and recent advances in ultrasound elastography techniques (Real-time Tissue Elastography^®, vibration-controlled transient elastography, point shear wave elastography, and two-dimensional shear wave elastography) used to evaluate the liver fibrosis stage and steatosis grade in patients with NAFLD.

A critical appraisal of the use of ultrasound in hepatic steatosis

Introduction: Nonalcoholic fatty liver disease (NAFLD) spans steatosis through nonalcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). NAFLD carries an increased risk of cardio-metabolic and liver-related events accounting for a substantial economic burden. Given that the natural history of NAFLD is critically dependent on the stage of fibrosis, non-invasively identifying the subgroup of patients at a higher risk of progressive disease is key. Areas covered: This review highlights the recent developments in the use of ultrasound-based techniques in NAFLD and their performance in predicting metabolic derangements, cardiovascular risk, and progression of liver disease, notably including diagnosis of fibrosing NASH, identification, and treatment of HCC. Expert opinion: Our ability to identify NAFLD patients and to estimate steatofibrosis with various ultrasound-based techniques has undergone tremendous progress over the last few years. However, it is more difficult to capture the inflammatory component of NASH with such ultrasound-assisted techniques. Moreover, semi-quantitative, quantitative, elastographic, and contrast-enhanced ultrasound techniques are increasingly being appreciated and made available but not all such techniques will gain success in the clinical and research area. Therefore, further research will precisely define the role of the most innovative ultrasonographic techniques, while reducing costs and increasing feasibility.

Diagnosis and management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in Western industrialised countries. The prevalence of NAFLD is increasing in parallel with the global rise in obesity and type 2 diabetes mellitus. NAFLD represents a spectrum of liver disease severity. NAFLD begins with accumulation of triacylglycerols in the liver (steatosis), and is defined by hepatic fatty infiltration amounting to greater than 5% by liver weight or the presence of over 5% of hepatocytes loaded with large fat vacuoles. In almost a quarter of affected individuals, steatosis progresses with the development of liver inflammation to non-alcoholic steatohepatitis (NASH). NASH is a potentially progressive liver condition and with ongoing liver injury and cell death can result in fibrosis. Progressive liver fibrosis may lead to the development of cirrhosis in a small proportion of patients. With the growing prevalence of NAFLD, there is an increasing need for a robust, accurate and non-invasive approach to diagnosing the different stages of this condition. This review will focus on (1) the biochemical tests and imaging techniques used to diagnose the different stages of NAFLD; and (2) a selection of the current management approaches focusing on lifestyle interventions and pharmacological therapies for NAFLD.

Noninvasive evaluation of nonalcoholic fatty liver disease: Current evidence and practice

With the increasing number of individuals with diabetes and obesity, nonalcoholic fatty liver disease (NAFLD) is becoming increasingly prevalent, affecting one-quarter of adults worldwide. The spectrum of NAFLD ranges from simple steatosis or nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH). NAFLD, especially NASH, may progress to fibrosis, leading to cirrhosis and hepatocellular carcinoma. NAFLD can impose a severe economic burden, and patients with NAFLD-related terminal or deteriorative liver diseases have become one of the main groups receiving liver transplantation. The increasing prevalence of NAFLD and the severe outcomes of NASH make it necessary to use effective methods to identify NAFLD. Although recognized as the gold standard, biopsy is limited by its sampling bias, poor acceptability, and severe complications, such as mortality, bleeding, and pain. Therefore, noninvasive methods are urgently needed to avoid biopsy for diagnosing NAFLD. This review discusses the current noninvasive methods for assessing NAFLD, including steatosis, NASH, and NAFLD-related fibrosis, and explores the advantages and disadvantages of measurement tools. In addition, we analyze potential noninvasive biomarkers for tracking disease processes and monitoring treatment effects, and explore effective algorithms consisting of imaging and nonimaging biomarkers for diagnosing advanced fibrosis and reducing unnecessary biopsies in clinical practice.

Nonalcoholic fatty liver with a hepatic arterial buffer response strongly associated with future metabolic disease

A change in hepatic blood flow caused by the hepatic arterial buffer response (HABR) occurs as fatty liver disease progress. The aim of this longitudinal cohort study was to investigate whether fatty liver with the HABR induces metabolic disorders. In 2009 and 2010, 494 (89.5%) participants were enrolled. The median follow‐up duration was 5.0 (interquartile range, 3.9‐6.0) years. The hazard ratios of fatty liver with the HABR for incident metabolic disorders were assessed by Cox proportional hazard models. A non–fatty liver group (non‐FL group, hepatorenal echo intensity ratio <1.12), a fatty liver without portal hypertension (FL group, hepatorenal echo intensity ratio ≥1.12 and ratio of the maximal blood velocity in the right hepatic artery to maximal blood velocity in the right portal vein <3.1) group, and a fatty liver with portal hypertension (FL‐HABR group, hepatorenal echo intensity ratio ≥1.12 and ratio of the maximal blood velocity in the right hepatic artery to maximal blood velocity in the right portal vein ≥3.1) group were defined based on echo intensity and Doppler ultrasonography. Fatty liver with and without the HABR was significantly associated with the incidence of diabetes on multivariate analysis (non‐FL versus FL group, hazard ratio, 3.36; 95% confidence interval, 1.05‐12.85; FL versus FL with the HABR group, HR, 2.68; 95% confidence interval, 1.28‐6.04). With respect to the incidence of hypertension and dyslipidemia, only FL with the HABR was a significant factor (hypertension, non‐FL versus FL, P = 0.874, FL versus FL‐HABR, P = 0.016, non‐FL versus FL‐HABR, P = 0.023; dyslipidemia, non‐FL versus FL, P = 0.311, FL versus FL‐HABR, P = 0.194, non‐FL versus FL‐HABR, P = 0.038). Conclusion: Fatty liver with the HABR is a high‐risk condition for metabolic diseases. (Hepatology Communications 2017;1:623–633)

[Techniques for quantification of liver fat in risk stratification of diabetics]

CLINICAL/METHODICAL ISSUE

Fatty liver disease plays an important role in the development of type 2 diabetes. Accurate techniques for detection and quantification of liver fat are essential for clinical diagnostics.

STANDARD RADIOLOGICAL METHODS

Chemical shift-encoded magnetic resonance imaging (MRI) is a simple approach to quantify liver fat content.

METHODICAL INNOVATIONS

Liver fat quantification using chemical shift-encoded MRI is influenced by several bias factors, such as T2* decay, T1 recovery and the multispectral complexity of fat.

PERFORMANCE

The confounder corrected proton density fat fraction is a simple approach to quantify liver fat with comparable results independent of the software and hardware used.

ACHIEVEMENTS

The proton density fat fraction is an accurate biomarker for assessment of liver fat.

PRACTICAL RECOMMENDATIONS

An accurate and reproducible quantification of liver fat using chemical shift-encoded MRI requires a calculation of the proton density fat fraction.

[Non-invasive assessment of fatty liver]

As the result of various harmful effects (infectious agents, metabolic diseases, unhealthy diet, obesity, toxic agents, autoimmune processes) hepatic damage may develop, which can progress towards liver steatosis, and fibrosis as well. The most common etiological factors of liver damages are hepatitis B and C infection, alcohol consumption and non-alcoholic fatty liver disease. Liver biopsy is considered as the gold standard for the diagnosis of chronic liver diseases. Due to the dangers and complications of liver biopsy, studies are focused on non-invasive markers and radiological imaging for liver steatosis, progression of fatty liver, activity of the necroinflammation and the severity of the fibrosis. Authors review the possibilities of non-invasive assessment of liver steatosis. The statistical features of the probes (positive, negative predictive values, sensitivity, specificity) are reviewed. The role of radiological imaging is also discussed. Although the non-invasive methods discussed in this article are useful to assess liver steatosis, further studies are needed to validate to follow progression of the diseases and to control therapeutic response.