Diagnostic accuracy of B-Mode ultrasound and Hepatorenal Index for graduation of hepatic steatosis in patients with chronic liver disease

Pancreatic Enzyme Replacement Leads to Increased Vitamin D Uptake in Patients Undergoing Sleeve-gastrectomy - A Prospective, Monocentric Trial

PURPOSE

Metabolic and bariatric surgery (MBS) is often considered to be associated with macro- and micronutrient deficiency. A possible treatment option can be the implementation of pancreatic enzyme replacement (PERT) and may lead to better outcomes. We designed a prospective trial investigating the possible impact of PERT in patients undergoing MBS at a high-volume center.

MATERIALS AND METHODS

A prospective two-arm randomized controlled trial was conducted on patients who underwent either sleeve gastrectomy or gastric bypass procedures at a high-volume center. Patients underwent bariatric surgery and follow-up examinations at 3, 6, and 12 months after surgery. Patients were stratified either to the treatment group with PERT or to the control group. The primary endpoint of the study was a change in BMI. Lab testing was carried out to measure secondary endpoints, including albumin and vitamin D levels.

RESULTS

Overall, 204 patients were enrolled. Due to missing follow-ups, surgical complications, and side effects due to Kreon medication, 65 were excluded. Analysis of primary endpoints indicates that PERT does not lead to slower weight loss or BMI reduction. Analysis of secondary endpoints showed significantly better vitamin D levels in patients undergoing MBS and PERT. No statistical difference was seen regarding albumin. In both arms, fatty liver disease improved. Quality of life is positively judged as comparable by patients in both groups.

CONCLUSION

Herein, we show an association between PERT and higher vitamin D levels in patients undergoing MBS. An optimized enzymatic environment due to PERT may therefore result in higher vitamin D levels and may improve clinical outcomes in patients undergoing MBS.

Pathophysiologic Mapping of Chronic Liver Diseases With Longitudinal Multiparametric MRI in Animal Models

OBJECTIVES

Chronic liver diseases (CLDs) have diverse etiologies. To better classify CLDs, we explored the ability of longitudinal multiparametric MRI (magnetic resonance imaging) in depicting alterations in liver morphology, inflammation, and hepatocyte and macrophage activity in murine high-fat diet (HFD)- and carbon tetrachloride (CCl 4 )-induced CLD models.

MATERIALS AND METHODS

Mice were either untreated, fed an HFD for 24 weeks, or injected with CCl 4 for 8 weeks. Longitudinal multiparametric MRI was performed every 4 weeks using a 7 T MRI scanner, including T1/T2 relaxometry, morphological T1/T2-weighted imaging, and fat-selective imaging. Diffusion-weighted imaging was applied to assess fibrotic remodeling and T1-weighted and T2*-weighted dynamic contrast-enhanced MRI and dynamic susceptibility contrast MRI using gadoxetic acid and ferucarbotran to target hepatocytes and the mononuclear phagocyte system, respectively. Imaging data were associated with histopathological and serological analyses. Principal component analysis and clustering were used to reveal underlying disease patterns.

RESULTS

The MRI parameters significantly correlated with histologically confirmed steatosis, fibrosis, and liver damage, with varying importance. No single MRI parameter exclusively correlated with 1 pathophysiological feature, underscoring the necessity for using parameter patterns. Clustering revealed early-stage, model-specific patterns. Although the HFD model exhibited pronounced liver fat content and fibrosis, the CCl 4 model indicated reduced liver fat content and impaired hepatocyte and macrophage function. In both models, MRI biomarkers of inflammation were elevated.

CONCLUSIONS

Multiparametric MRI patterns can be assigned to pathophysiological processes and used for murine CLD classification and progression tracking. These MRI biomarker patterns can directly be explored clinically to improve early CLD detection and differentiation and to refine treatments.

Revisiting the Hepatorenal Index in the Quantification of Hepatic Steatosis: How it is done and the utility

METHODS

Twenty-three peer-reviewed articles on HRI measurements published between 2018 through 2023 were reviewed, and 11 were selected based on common subjects. The search terms included "hepatorenal index," "HRI," "HRI ultrasound," "hepatorenal ultrasound index," and "HRI ultrasound measurement."Three common subject areas were identified in the literature and synthesized down to 11 articles. The common subjects identified were HRI technique, HRI limitations, and HRI diagnostic accuracy. The matrix provided a quick overview of the general information in each piece, aiding in the paper's overall organization. Thirteen articles were rejected as not relevant or out of date. The research question leading this review was, "What does the literature say about the value of HRI in determining moderate to severe hepatic steatosis?"

RESULTS

The literature revealed that HRI could be valuable in determining moderate to severe hepatic steatosis. HRI could not accurately determine normal or mild steatosis and has several limitations.

CONCLUSIONS

HRI is a more objective method for determining the degree of hepatic steatosis compared with traditional B-mode ultrasound scoring and does not require additional or specialized equipment. Many studies excluded patients with various liver diseases, which may not make HRI a practical tool for clinical usefulness. Further studies should be conducted with larger patient cohorts, a greater degree of hepatic steatosis, and determine specific standardized cutoff values.

Hepatic steatosis: Qualitative and quantitative sonographic assessment in comparison to histology

Introduction

Globally, B-mode ultrasound is the most common modality used for the diagnosis of hepatic steatosis. We aimed to assess the correlation between qualitative liver ultrasound parameters, attenuation imaging (ATI) and histopathology-diagnosed steatosis grade obtained from liver biopsy. Our secondary aim was to examine the interobserver variability of qualitative ultrasound features.

Methods

A retrospective cohort study was performed which included adult patients (age ≥ 18 years) who had same-day liver ultrasound, ATI and liver biopsy for grading hepatic steatosis severity between 2018 and 2022. The qualitative US features for hepatic steatosis were independently scored by three radiologists and interobserver variability was examined. Histologic steatosis grade, ATI and qualitative ultrasound parameters were compared.

Results

Ninety patients were included; 67% female with a median age of 54 (IQR 39-65) years. The radiologist's overall impression had the highest correlation (very strongly correlated) with histologic steatosis grade (r = 0.82, P < 0.001). ATI coefficient and all qualitative ultrasound B-mode features except for liver echotexture and focal fat sparing were strongly correlated with histologic steatosis grade (r ≥ 0.70, P < 0.001). Most qualitative ultrasound features had good agreement between observers (Kappa statistic 0.61-1.0, P < 0.001), (Kendall coefficient 0.92, P < 0.001).

Conclusion

The examined qualitative ultrasound parameters and ATI had good-excellent performance for diagnosing clinically significant hepatic steatosis; however, the radiologist's overall impression had the best correlation with histologic steatosis grade. Our findings suggest an ongoing role for qualitative liver ultrasound assessment of hepatic steatosis despite the emergence of newer quantitative measures.

Early and accurate diagnosis of steatotic liver by artificial intelligence (AI)-supported ultrasonography

OBJECTIVES

Steatotic liver disease is the most frequent chronic liver disease worldwide. Ultrasonography (US) is commonly employed for the assessment and diagnosis. Few information is available on the possible use of artificial intelligence (AI) to ameliorate the diagnostic accuracy of ultrasonography.

MATERIALS AND METHODS

An AI-based algorithm was developed using a dataset of US images. We prospectively enrolled 134 patients for algorithm validation. Patients underwent abdominal US and Proton Density Fat Fraction MRI scans (MRI-PDFF), assumed as reference technique. The hepatorenal index was manually calculated (HRIM) by 4 operators. An automatic hepatorenal index (HRIA) was obtained by the algorithm. The accuracy of HRIA to discriminate steatosis grades was evaluated by ROC analysis using MRI-PDFF cut-offs.

RESULTS

Overweight was 40 % of subjects (BMI 26.4 kg/cm2). The median HRIA was 1.11 (IQR 0.32) and the average of 4 manually calculated HRIM was 1.08 (IQR 0.26), with a 15 % inter-operator variability. Both HRIA (R = 0.79, P < 0.0001) and HRIM (R = 0.69, P < 0.0001) significantly correlated with liver fat percentage (MRI-PDFF). According to MRI-PDFF, 32 % of enrolled subjects had steatosis. Discrimination capacity by AUC between patient with steatosis and patient without steatosis was better for HRIA than HRIM (AUC: 0.87 vs. 0.82, respectively). ROC analysis showed an AUC = 0.98 for HRIA with 1.64 cut-off in distinguishing between mild and moderate/severe groups.

CONCLUSIONS

The use of AI improves accuracy and speed of ultrasonography in the diagnosis of liver steatosis. Further studies should evaluate the routine use of this technique in the management of liver steatosis at high cardio-metabolic risk.

Diagnostic Performance of Greyscale Ultrasound in Detecting Fatty Liver Disease in a Type 2 Diabetes Population Using FibroScan as the Reference Standard

Introduction Brightness mode ultrasound (B-mode US) and FibroScan (Echosens, Paris, France) are the two ultrasound methods often recommended for screening non-alcoholic fatty liver disease (NAFLD) in persons with type 2 diabetes mellitus (T2DM). This study assessed the diagnostic performance of B-mode US using FibroScan as the reference standard. Methods Persons with a known history of T2DM were invited to screen for NAFLD using B-mode US and FibroScan on separate days within a one-month period. Assessors of B-mode US and FibroScan were blinded to each other's findings. Both B-mode US and FibroScan independently assessed and graded each participant for the presence of NAFLD. Using the diagnostic test findings of FibroScan as a reference standard, the sensitivity and specificity of B-mode US were analyzed. The area under the receiver operating characteristic curve (AUROC) was analyzed using Jamovi (version 2.3.21). A multinomial logistic regression of the B-mode US and FibroScan in predicting NAFLD grade was also analyzed. Results A total of 171 participants were assessed. B-mode US detected NAFLD in T2DM patients with 63.6% sensitivity, 65.6% specificity, and 0.646 AUROC. Sensitivity and specificity in overweight and obese participants were 36-43% and 76-85%, respectively. Multinomial logistic regression demonstrated an insignificant statistical relationship between FibroScan and B-mode US in predicting grade 1 steatosis (p-value = 0.397), which was significantly affected by a higher BMI (p-value = 0.034) rather than a higher liver fibrosis level (p-value = 0.941). The logistic regression further showed a significant relationship between B-mode US and FibroScan in predicting steatosis grade 2 (p-value = 0.045) and grade 3 (p-value < 0.001), which was not significantly affected by BMI (p-value = 0.091). Conclusion B-mode US can replace FibroScan for severe steatosis; however, it cannot be used to screen for NAFLD in T2DM patients due to lower sensitivity for early detection in the overweight.

Technical Acoustic Measurements Combined with Clinical Parameters for the Differential Diagnosis of Nonalcoholic Steatohepatitis

Background and aim: Diagnosing nonalcoholic steatohepatitis (NASH) is challenging. This study intended to explore the diagnostic value of multiple technical acoustic measurements in the diagnosis of NASH, and to establish a diagnostic model combining technical acoustic measurements with clinical parameters to improve the diagnostic efficacy of NASH. Methods: We consecutively enrolled 75 patients with clinically suspected nonalcoholic fatty liver disease (NAFLD) who underwent percutaneous liver biopsy in our hospital from June 2020 to December 2021. All cases underwent multiple advanced acoustic measurements for liver such as shear wave dispersion (SWD), shear wave speed (SWS), attenuation imaging (ATI), normalized local variance (NLV), and liver-kidney intensity ratio (Ratio) examination before liver biopsies. A nomogram prediction model combining the technical acoustic measurements and clinical parameters was established and the model is proposed to improve the diagnostic performance of NASH. Results: A total of 75 cases were included in this study. The classification of pathological grade for NASH was as follows: normal liver, (n = 15, 20%), nonalcoholic fatty liver (NAFL), (n = 44, 58.7%), and NASH, (n = 16, 21.3%). There were statistically significant differences in SWS (p = 0.002), acoustic coefficient (AC) (p = 0.018), NLV (p = 0.033), age (p = 0.013) and fasting blood glucose (Glu) (p = 0.049) between NASH and non-NASH. A nomogram model which includes SWS, AC, NLV, age and Glu was built to predict NASH, and the calibration curves showed good calibrations in both training and validation sets. The AUCs of the combined nomogram model for the training set and validation set were 0.8597 and 0.7794, respectively. Conclusion: There were statistically significant differences in SWS, AC, NLV, age and Glu between NASH and non-NASH. A nomogram model which includes SWS, AC, NLV, age and Glu was built to predict NASH. The predictive model has a higher diagnostic performance than a single factor model in the diagnosis of NASH and has good clinical application prospects.

Evaluation of Artificial Intelligence-Calculated Hepatorenal Index for Diagnosing Mild and Moderate Hepatic Steatosis in Non-Alcoholic Fatty Liver Disease

Background and Objectives: This study aims to evaluate artificial intelligence-calculated hepatorenal index (AI-HRI) as a diagnostic method for hepatic steatosis. Materials and Methods: We prospectively enrolled 102 patients with clinically suspected non-alcoholic fatty liver disease (NAFLD). All patients had a quantitative ultrasound (QUS), including AI-HRI, ultrasound attenuation coefficient (AC,) and ultrasound backscatter-distribution coefficient (SC) measurements. The ultrasonographic fatty liver indicator (US-FLI) score was also calculated. The magnetic resonance imaging fat fraction (MRI-PDFF) was the reference to classify patients into four grades of steatosis: none < 5%, mild 5–10%, moderate 10–20%, and severe ≥ 20%. We compared AI-HRI between steatosis grades and calculated Spearman’s correlation (rs) between the methods. We determined the agreement between AI-HRI by two examiners using the intraclass correlation coefficient (ICC) of 68 cases. We performed a receiver operating characteristics (ROC) analysis to estimate the area under the curve (AUC) for AI-HRI. Results: The mean AI-HRI was 2.27 (standard deviation, ±0.96) in the patient cohort. The AI-HRI was significantly different between groups without (1.480 ± 0.607, p < 0.003) and with mild steatosis (2.155 ± 0.776), as well as between mild and moderate steatosis (2.777 ± 0.923, p < 0.018). AI-HRI showed moderate correlation with AC (rs = 0.597), SC (rs = 0.473), US-FLI (rs = 0.5), and MRI-PDFF (rs = 0.528). The agreement in AI-HRI was good between the two examiners (ICC = 0.635, 95% confidence interval (CI) = 0.411–0.774, p < 0.001). The AI-HRI could detect mild steatosis (AUC = 0.758, 95% CI = 0.621–0.894) with fair and moderate/severe steatosis (AUC = 0.803, 95% CI = 0.721–0.885) with good accuracy. However, the performance of AI-HRI was not significantly different (p < 0.578) between the two diagnostic tasks. Conclusions: AI-HRI is an easy-to-use, reproducible, and accurate QUS method for diagnosing mild and moderate hepatic steatosis.

Improving diagnostic accuracy of ultrasound texture features in detecting and quantifying hepatic steatosis using various beamforming sound speeds

Objective.While ultrasound image texture has been utilized to detect and quantify hepatic steatosis, the texture features extracted using a single (conventionally 1540 m s-1) beamforming speed of sound (SoS) failed to achieve reliable diagnostic performance. This study aimed to investigate if the texture features extracted using various beamforming SoSs can improve the accuracy of hepatic steatosis detection and quantification.Approach.Patients with suspected non-alcoholic fatty liver disease underwent liver biopsy or MRI proton density fat fraction (PDFF) as part of standard of care, were prospectively enrolled. The radio-frequency data from subjects' right and left liver lobes were collected using 6 beamforming SoSs: 1300, 1350, 1400, 1450, 1500 and 1540 m s-1and analyzed offline. The texture features, i.e. Contrast, Correlation, Energy and Homogeneity from gray-level co-occurrence matrix of normalized envelope were obtained from a region of interest in the liver parenchyma.Main results.Forty-three subjects (67.2%) were diagnosed with steatosis while 21 had no steatosis. Homogeneity showed the area under the curve (AUC) of 0.75-0.82 and 0.58-0.81 for left and right lobes, respectively with varying beamforming SoSs. The combined Homogeneity value over 1300-1540 m s-1from left and right lobes showed the AUC of 0.90 and 0.81, respectively. Furthermore, the combined Homogeneity values from left and right lobes over 1300-1540 m s-1improved the AUC to 0.94. The correlation between texture features and steatosis severity was improved by using the images from various beamforming SoSs. The combined Contrast values over 1300-1540 m s-1from left and right lobes demonstrated the highest correlation (r= 0.90) with the MRI PDFF while the combined Homogeneity values over 1300-1540 m s-1from left and right lobes showed the highest correlation with the biopsy grades (r= -0.81).Significance.The diagnostic accuracy of ultrasound texture features in detecting and quantifying hepatic steatosis was improved by combining its values extracted using various beamforming SoSs.

Hepatorenal Index by B-Mode Ratio Versus Imaging and Fatty Liver Index to Diagnose Steatosis in Alcohol-Related and Nonalcoholic Fatty Liver Disease

OBJECTIVES

We aimed to evaluate the accuracy of the hepatorenal index by B-mode ratio to diagnose hepatic steatosis, compared to ultrasound steatosis score, controlled attenuation parameter, and the fatty liver index using histology as the gold standard.

METHODS

We prospectively included participants with alcohol-related or nonalcoholic fatty liver disease for same-day noninvasive investigations and liver biopsy.

RESULTS

We included 137 participants, 72% male, median age 60 years (53-65) and body mass index 32 kg/m² (28-38). Eighty percent had steatosis (S0/S1/S2/S3 = 20/37/24/19%). B-mode ratio had moderate diagnostic accuracy for any steatosis (≥S1, area under the receiver operating characteristics curve [AUROC] = 0.79; 95% confidence interval 0.70-0.88), significant steatosis (≥S2, AUROC = 0.76; 0.66-0.85), and severe steatosis (=S3, AUROC = 0.74; 0.62-0.86), independent of disease etiology. The cutoff values to rule-out and rule-in any steatosis were 1.09 and 1.45. While B-mode ratio and controlled attenuation parameter correlated poorly, their diagnostic accuracies were comparable to each other and to ultrasound steatosis scoring. Fatty liver index did not differ from B-mode ratio in detecting any steatosis but had poor accuracy to detect higher steatosis grades. B-mode ratio measurements failed in 12% of patients, compared to 1% for ultrasound steatosis scoring and 2% for controlled attenuation parameter.

CONCLUSION

The hepatorenal index by B-mode ratio diagnose steatosis with moderate accuracy in patients with alcohol-related or nonalcoholic fatty liver disease, comparable to B-mode ultrasound steatosis scoring and controlled attenuation parameter. However, its clinical use is limited by a high failure rate.

US Backscatter for Liver Fat Quantification: An AIUM-RSNA QIBA Pulse-Echo Quantitative Ultrasound Initiative

Nonalcoholic fatty liver disease (NAFLD) is believed to affect one-third of American adults. Noninvasive methods that enable detection and monitoring of NAFLD have the potential for great public health benefits. Because of its low cost, portability, and noninvasiveness, US is an attractive alternative to both biopsy and MRI in the assessment of liver steatosis. NAFLD is qualitatively associated with enhanced B-mode US echogenicity, but visual measures of B-mode echogenicity are negatively affected by interobserver variability. Alternatively, quantitative backscatter parameters, including the hepatorenal index and backscatter coefficient, are being investigated with the goal of improving US-based characterization of NAFLD. The American Institute of Ultrasound in Medicine and Radiological Society of North America Quantitative Imaging Biomarkers Alliance are working to standardize US acquisition protocols and data analysis methods to improve the diagnostic performance of the backscatter coefficient in liver fat assessment. This review article explains the science and clinical evidence underlying backscatter for liver fat assessment. Recommendations for data collection are discussed, with the aim of minimizing potential confounding effects associated with technical and biologic variables.

Ultrasound Methods for the Assessment of Liver Steatosis: A Critical Appraisal

The prevalence of the non-alcoholic fatty liver disease has reached major proportions, being estimated to affect one-quarter of the global population. The reference techniques, which include liver biopsy and the magnetic resonance imaging proton density fat fraction, have objective practical and financial limitations to their routine use in the detection and quantification of liver steatosis. Therefore, there has been a rising necessity for the development of new inexpensive, widely applicable and reliable non-invasive diagnostic tools. The controlled attenuation parameter has been considered the point-of-care technique for the assessment of liver steatosis for a long period of time. Recently, many ultrasound (US) system manufacturers have developed proprietary software solutions for the quantification of liver steatosis. Some of these methods have already been extensively tested with very good performance results reported, while others are still under evaluation. This manuscript reviews the currently available US-based methods for diagnosing and grading liver steatosis, including their classification and performance results, with an appraisal of the importance of this armamentarium in daily clinical practice.

Role of Ultrasound Methods for the Assessment of NAFLD

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease worldwide. The prevalence in patients with type 2 diabetes mellitus is between 55–80%. The spectrum of NALFD ranges from simple steatosis to aggressive steatohepatitis with potentially progressive liver fibrosis up to cirrhosis and hepatocellular carcinoma. In clinical practice, there are two important aims: First to make the diagnosis of NAFLD, and second, to identify patients with advanced fibrosis, because extent of fibrosis is strongly associated with overall mortality, cardiovascular disease, hepatocellular carcinoma, and extrahepatic malignancy. Histology by liver biopsy can deliver this information, but it is an invasive procedure with rare, but potentially severe, complications. Therefore, non-invasive techniques were developed to stage fibrosis. Ultrasound is the primary imaging modality in the assessment of patients with confirmed or suspected NAFLD. This narrative review focus on different ultrasound methods to detect and graduate hepatic steatosis and to determine grade of fibrosis using elastography-methods, such as transient elastography and 2-dimensional shear wave elastography in patients with NAFLD. Particular attention is paid to the application and limitations in overweight patients in clinical practice. Finally, the role of B-mode ultrasound in NAFLD patients to screen for hepatocellular carcinoma is outlined.

Steatosis Grading Comparison Between Qualitative Ultrasonography and Magnetic Resonance Spectroscopy in Patients With Nonalcoholic Fatty Liver Disease

Objective:

Assess the correlation between the qualitative sonographic score for detecting hepatic steatosis (HS) and liver fat quantification, using proton magnetic resonance spectroscopy (MRS).

Materials and Methods:

Sixty-six patients with known or suspected nonalcoholic fatty liver disease (NAFLD) underwent ultrasonography (US) and magnetic resonance imaging (MRI). The qualitative sonographic score and fat quantification, measured by MRS, were the techniques used. A Kappa coefficient was used for agreement calculation, and a Fisher test was used to assess the normality of the variables. The MRS results were the gold standard for US quality assessment.

Results:

The agreement between MRS and US was 50% (Kappa 0.35). Ultrasonography results were more severe in 42.4% of the cases, and 66.7% of the patients had a body mass index greater than 30 ( P = .017). For diagnosis of HS, US presented 100% sensitivity, 30.8% to 60% specificity, 61.7% to 72.7% accuracy, 40% to 69.2% false-positive rate, 0% false-negative rate, 53.8% positive predictive value, and 100% negative predictive value.

Conclusion:

Ultrasonography is a reliable exam for detecting HS, although not for grading purposes. Therefore, US is not a good predictor of HS severity for the management and follow-up of NAFLD.

Efficacy of B-mode ultrasound-based attenuation for the diagnosis of hepatic steatosis: a systematic review/meta-analysis

The accuracy of attenuation coefficients and B-mode ultrasound for distinguishing between S0 (healthy, < 5% fat) and S1-3 (steatosis ≥ 5%) livers compared to a controlled attenuation parameter is unclear. This meta-analysis aimed to comprehensively assess the diagnostic performance of B-mode ultrasound imaging for evaluating steatosis of ≥ 5%. We searched the PubMed, Embase, and Web of Science databases for studies on the accuracy of B-mode ultrasound for differentiating S0 from S1-3 in adults with chronic liver disease. A bivariate random-effects model was performed to estimate the pooled sensitivity, specificity, positive (PLR) and negative likelihood ratios (NLR), and diagnostic odds ratios (DORs). Subgroup analyses by attenuation coefficient, conventional B-mode ultrasound findings, and B-mode ultrasound findings without semi-quantification methods were performed. Liver steatosis was scored as follows: S0, < 5%; S1, 5-33%; S2, 33-66%; and S3, > 66%. Nineteen studies involving 3240 patients were analyzed. The pooled sensitivity and specificity of B-mode ultrasound for detecting S1 were 0.70 (95% confidence interval [CI], 0.63-0.77) and 0.86 (95% CI 0.82-0.89), respectively. The pooled PLR, NLR, and DOR were 4.90 (95% CI 3.69-6.51), 0.35 (95% CI 0.27- 0.44), and 14.1 (95% CI 8.7-23.0), respectively. The diagnostic accuracy was better in patients with attenuation coefficients (area under the curve [AUC], 0.89; sensitivity, 0.75; specificity, 0.86) than in those with conventional B-mode findings (AUC, 0.80; sensitivity, 0.59; specificity, 0.83). In particular, the diagnostic value was better when the attenuation coefficient guided by B-mode ultrasound was utilized. To screen patients with steatosis of ≥ 5%, attenuation coefficient should be used.

Non-Alcoholic Fatty Liver Disease and Hypothyroidism: Review of Clinical and Experimental Studies

Hypothyroidism is a widespread condition affecting people of different socio-economic background and geographical location. A lot of studies highlight the effect of hypothyroidism on the metabolic processes in various organs, including the liver. On the other hand, liver damage often results in the development of non-alcoholic fatty liver disease; however, the data on the impact of hypothyroidism on liver morphology, which can serve as a direct indicator and marker of liver condition and function, are limited and controversial. In this report, we reviewed the relationship between non-alcoholic fatty liver disease and hypothyroidism with an accent on morphological alteration of the liver discovered in clinical and experimental studies.

Pathological findings of liver steatosis that is difficult to evaluate with ultrasound

Although new ultrasound (US) methods able to quantitatively assess liver fat content have been recently developed, B-mode US is still the major method for detecting liver steatosis during medical checkups. However, some pathological cases yield false-positive or false-negative liver steatosis results using B-mode US. In addition, histologically, the degree of fat deposits and the size of fat droplets in the liver can affect the sensitivity and specificity of the diagnosis of liver steatosis using B-mode US. As B-mode US evaluation of fatty liver relies on operator expertise, the operator should be aware that there are some cases of liver steatosis that are difficult to evaluate with B-mode US. Here, we describe the pathological findings of liver steatosis that is difficult to evaluate with US.

Ultrasonographic grayscale findings related to fibrosis in patients with non-alcoholic fatty liver disease: comparison with transient elastography and Fib-4 index

PURPOSE

Fibrosis is a predictor of mortality in patients with non-alcoholic fatty liver disease (NAFLD). In our institution, abdominal ultrasonography has been performed based on a unified method consisting of 25 images. We investigated ultrasonographic grayscale findings related to fibrosis in patients with NAFLD.

METHODS

This retrospective study comprised 41 cases of pathologically proven fatty liver between January 2015 and September 2020. A total of 26 ultrasonographic findings were subjectively evaluated. These findings, transient elastography (TE) with M probe, and FIB-4 index were compared with fibrosis stage.

RESULTS

The frequency of roughness of the dorsal side of the surface (p < 0.001), heterogenicity of the parenchyma (p = 0.003), narrowing of the hepatic vein (p = 0.004), and splenomegaly (p < 0.001) were strongly correlated with the fibrosis stage. Logistic regression analysis for stage ≥ 3 showed narrowing of the hepatic vein (odds ratio [OR] 5.860, p = 0.031) and splenomegaly (OR 6.290, p = 0.028). Logistic regression analysis for stage 4 showed roughness of the ventral side of the surface (OR 42.0, p = 0.019). The AUROC for stage 3 and stage 4 with the number of positive ultrasonographic findings was 0.856, and 0.940, respectively. The AUROC for F3 and F4 with TE was 0.831 and 0.861, respectively. The AUROC for stage 3 and stage 4 with FIB-4 index was 0.815 and 0.806, respectively.

CONCLUSIONS

Narrowing of the hepatic vein, roughness of the dorsal side of the surface, heterogenicity of the parenchyma, and splenomegaly and their combination could predict fibrosis in patients with NAFLD.

Ultrasound-based techniques for noninvasive diagnosis of liver steatosis in nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has become a worldwide medical and social problem. Although nonalcoholic steatosis can be reversed, some patients still progress to nonalcoholic steatohepatitis, liver cirrhosis, and even liver cancer. Therefore, early diagnosis and accurate disease assessment of NAFLD have become an important basis for its intervention treatment and prognosis improvement. Although liver biopsy is the gold standard for the diagnosis of NAFLD, it is not an ideal reference standard, and MRI-PDFF is more often used in clinical research. The non-invasive examination based on ultrasound detection has also become a hot spot of NAFLD research. This paper discusses the ultrasonic diagnosis technology for liver steatosis in NAFLD, with an aim to provide a safe and practical basis for the diagnosis, disease evaluation, and treatment intervention of NAFLD.

Diagnostic Value of Ultrasound in Fatty Liver Disease

Hepatic steatosis is a commonly seen phenomenon in clinical practice and is the result of the accumulation of lipids in the hepatocytes. In most cases steatosis refers to nonalcoholic fatty liver disease (NAFLD), but it also occurs in other diseases of the liver parenchyma of a different etiology and is the result of the dysregulation of metabolic processes. Consequently, inflammatory processes can induce progressive fibrosis. Due to the high prevalence of fatty liver disease, a further increase in metabolic liver cirrhosis with corresponding complications can be expected in the near future. Due to its broad availability, ultrasound is particularly important, especially for the management of NAFLD. In addition to diagnosis and risk stratification, the monitoring of high-risk patients in NAFLD is becoming increasingly clinically important. Multimodality ultrasound includes B-mode and duplex methods, analysis of tissue stiffness (elastography), contrast-enhanced imaging (CEUS), and steatosis quantification. When using ultrasound in fatty liver disease, a standardized approach that takes into account the limitations of the method is essential.

Hepatorenal index for grading liver steatosis with concomitant fibrosis

Introduction

Ultrasonography is widely used as the first tool to evaluate fatty liver disease, and the hepatorenal index is a semi-quantitative method that improves its performance. Fibrosis can co-exist with steatosis or even replace it during disease progression. This study aimed to evaluate the influence of fibrosis on the measurement of steatosis using the hepatorenal index.

Materials and methods

This cross-sectional study included 89 patients with nonalcoholic fatty liver disease and in whom liver fibrosis was determined by ultrasound elastography. The Pearson’s correlation coefficient was used to compare between the results of the sonographic hepatorenal index and the quantification of steatosis using magnetic resonance spectroscopy as well the accuracy of detecting moderate to severe steatosis using sonography in two groups of patients: (A) without advanced fibrosis and (B) with advanced fibrosis. Advanced fibrosis was defined as a shear wave speed ≥ 1.78 m/s on ultrasound elastography. We calculated the area under the curve (AUC-ROC) to detect the ability of the hepatorenal index to differentiate light from moderate to severe steatosis in both groups. Moderate to severe steatosis was defined as a fat fraction > 15% on the magnetic resonance spectroscopy. The intra-observer variability was assessed using the Bland-Altman plot.

Results

Among patients, the mean age was 54.6 years and 59.6% were women, 50.6% had a body mass index ≥ 30 kg/m², 29.2% had moderate to severe steatosis, and 27.2% had advanced fibrosis. There was a correlation between steatosis grading by ultrasonography and magnetic resonance in group A (0.73; P < 0.001), but not in Group B (0.33; P = 0.058). The AUC-ROC for detecting a steatosis fraction ≥ 15% was 0.90 and 0.74 in group A and group B, respectively. The intra-observer variability for the hepatorenal index measurements was not significant (-0.036; P = 0.242).

Conclusion

The hepatorenal index is not appropriate for estimating steatosis in livers with advanced fibrosis.

Usefulness of Different Imaging Modalities in Evaluation of Patients with Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are becoming some of the major health problems in well-developed countries, together with the increasing prevalence of obesity, metabolic syndrome, and all of their systemic complications. As the future prognoses are even more disturbing and point toward further increase in population affected with NAFLD/NASH, there is an urgent need for widely available and reliable diagnostic methods. Consensus on a non-invasive, accurate diagnostic modality for the use in ongoing clinical trials is also required, particularly considering a current lack of any registered drug for the treatment of NAFLD/NASH. The aim of this narrative review was to present current information on methods used to assess liver steatosis and fibrosis. There are several imaging modalities for the assessment of hepatic steatosis ranging from simple density analysis by computed tomography or conventional B-mode ultrasound to magnetic resonance spectroscopy (MRS), magnetic resonance imaging proton density fat fraction (MRI-PDFF) or controlled attenuation parameter (CAP). Fibrosis stage can be assessed by magnetic resonance elastography (MRE) or different ultrasound-based techniques: transient elastography (TE), shear-wave elastography (SWE) and acoustic radiation force impulse (ARFI). Although all of these methods have been validated against liver biopsy as the reference standard and provided good accuracy, the MRS and MRI-PDFF currently outperform other methods in terms of diagnosis of steatosis, and MRE in terms of evaluation of fibrosis.