Liver stiffness quantification in biopsy-proven nonalcoholic fatty liver disease patients using shear wave elastography in comparison with transient elastography

Ultrasound-derived fat fraction to assess liver steatosis in obese patients with polycystic ovary syndrome

This study aims to explore the characteristics and influencing factors of ultrasound-derived fat fraction (UDFF) in obese patients with polycystic ovary syndrome (PCOS). Evaluate the diagnostic value of UDFF for MAFLD. This study included 124 obese PCOS patients and 106 age- and body mass index (BMI)-matched obese women, collecting clinical data from both groups. Compare the characteristics and related factors of hepatic steatosis between two groups. A total of 124 obese PCOS patients were divided into MAFLD group (n = 64) and no MAFLD group (n = 60). Binary logistic regression was used to analyze the independent risk factors for MAFLD in obese PCOS patients, and Spearman correlation analysis was used to examine the correlation between UDFF and various variables. The MAFLD group was further divided into mild group (S1, n = 16), moderate group (S2, n = 24), and severe group (S3, n = 24). Based on the ultrasound results, draw a receiver operating characteristic curve (ROC) for diagnosing the degree of hepatic steatosis in obese PCOS patients using UDFF. MAFLD was more common in the obese PCOS group than in the simple obese group (51.61% vs. 40.57%, P < 0.05). UDFF is positively correlated with the severity of MAFLD (r = 0.603, P < 0.01). The AUC for diagnosing liver steatosis with S ≥ 1, S ≥ 2, and S = 3 using UDFF is 0.935, 0.951, and 0.916. UDFF has certain diagnostic value for metabolic-related fatty liver disease in obese PCOS patients, and UDFF levels gradually increase with the severity of MAFLD.

Performance of ultrasound-guided attenuation parameter and 2D shear wave elastography in patients with metabolic dysfunction-associated steatotic liver disease

PURPOSE

To assess the performance and the reproducibility of ultrasound-guided attenuation parameter (UGAP) and two-dimensional shear wave elastography (2D-SWE) in patients with biopsy-proven metabolic dysfunction-associated steatotic liver disease (MASLD).

METHODS

This study included consecutive adult patients with MASLD who underwent ultrasound with UGAP, 2D-SWE and percutaneous liver biopsy. The median values of 12 consecutive UGAP measurements were acquired by two independent radiologists (R1 and R2). Hepatic steatosis was graded by liver biopsy as: (0) < 5%; (1) 5-33%; (2) > 33-66%; (3) > 66%. Areas under the curve (AUCs) were calculated to determine the diagnostic performance. Inter- and intra-observer reliability was assessed with intraclass correlation coefficient (ICC).

RESULTS

A hundred patients (median age 55.0 years old) with MASLD were prospectively enrolled. At histopathology, 70 and 42 patients had grade ≥ 2 and 3 steatosis, respectively. Median UGAP was 0.78 dB/cm/MHz (IQR/Med: 5.55%). For the diagnosis of grade ≥ 2 steatosis, the AUCs of UGAP were 0.828 (95% CI: 0.739, 0.896) for R1 and 0.779 (95% CI: 0.685, 0.856) for R2. The inter- and intra-operator reliability of UGAP were excellent, with an ICC of 0.92 (95% CI: 0.87-0.95) and 0.95 (95% CI: 0.92-0.96), respectively. The median liver stiffness was 6.76 kPa (IQR/Med: 16.30%). For the diagnosis of advanced fibrosis, 2D-SWE had an AUC of 0.862 (95% CI: 0.757, 0.934), and the optimal cutoff value was > 6.75 kPa with a sensitivity of 80.6% and a specificity of 75.7%.

CONCLUSION

UGAP and 2D-SWE provide a good performance for the staging of steatosis and fibrosis in patients with MASLD with an excellent intra-operator reliability of UGAP.

KEY POINTS

Question How well do ultrasound-guided attenuation parameter (UGAP) and two-dimensional shear wave elastography (2D-SWE) perform for quantifying hepatic steatosis and fibrosis? Findings UGAP had a maximum AUC of 0.828 for the diagnosis of grade ≥ 2 steatosis, and 2D-SWE had an AUC of 0.862 for diagnosing advanced fibrosis. Clinical relevance UGAP and 2D-SWE allow rapid, reproducible, and accurate quantification of hepatic steatosis and fibrosis that can be used for the noninvasive assessment of patients with metabolic dysfunction-associated steatotic liver disease.

Modern ultrasound techniques for diagnosing liver steatosis and fibrosis: A systematic review with a focus on biopsy comparison

BACKGROUND

This review evaluated the diagnostic effectiveness of various ultrasound (US) methods compared to liver biopsy.

AIM

To determine the diagnostic accuracy of US techniques in assessing liver fibrosis and steatosis in adults, using the area under the receiver operating characteristic curve (AUROC) as the standard measure.

METHODS

The review included original retrospective or prospective studies published in the last three years in peer-reviewed medical journals, that reported AUROC values. Studies were identified through PubMed searches on January 3 and April 30, 2024. Quality was assessed using the QUADAS-2 tool. Results were tabulated according to the diagnostic method and the type of liver pathology.

RESULTS

The review included 52 studies. For liver fibrosis detection, 2D-shear wave elastography (SWE) AUROCs ranged from 0.54 to 0.994, showing better accuracy for advanced stages. Modifications, including 2D-SWE with propagation map guidance and supersonic imagine achieved AUROCs of 0.84 to nearly 1.0. point SWE and classical SWE had AUROCs of 0.741-0.99, and 0.507-0.995, respectively. Transient elastography (TE), visual TE, vibration-controlled TE (VCTE), and FibroTouch reported AUROCs close to 1.0. For steatosis, VCTE with controlled attenuation parameter showed AUROCs up to 0.89 (for ≥ S1), acoustic radiation force impulse ranged from 0.762 to 0.784, US attenuation parameter from 0.88 to 0.93, and normalized local variance measurement from 0.583 to 0.875. Most studies had a low risk of bias across all or most domains, but evidence was limited by variability in study quality and small sample sizes. Innovative SWE variants were evaluated in a single study.

CONCLUSION

Modern US techniques can serve as effective noninvasive diagnostic tools for liver fibrosis and steatosis, with the potential to reduce the reliance on biopsies.

Evaluation of ultrasound derived fat fraction for metabolic associated fatty liver disease in obese patients with polycystic ovary syndrome

OBJECTIVE

To explore the application of ultrasound derived fat fraction (UDFF) in evaluating metabolic associated fatty liver disease in obese polycystic ovary syndrome.

METHOD

This study included 124 obese PCOS patients and 106 age and body mass index (BMI) matched non PCOS control group women. The two groups of data were compared to determine the prevalence of metabolic associated fatty liver disease (MAFLD) in PCOS obese patients. The 124 obese PCOS patients were divided into MAFLD group (n = 64) and non MAFLD group (n = 60). Using ROC curve analysis to evaluate the diagnostic performance of UDFF and SWV values for MAFLD. The MAFLD group was divided into mild group (n = 16), moderate group (n = 24), and severe group (n = 24). Use Spearman correlation method to analyze the relationship between UDFF value, SWV value and the severity of MAFLD.

RESULT

MAFLD was more common in the obese PCOS group than in the control group (51.61 vs 27.36%) (χ2 = 13.9583, P = 0.00019). The UDFF of obese PCOS patients was higher than those of the control group, while SWV was lower than those of the control group. ROC analysis showed that the AUC of UDFF for diagnosing MAFLD was 0.935, with sensitivity, specificity, and cut-off values of 92.2, 85.0, and 4.5%, respectively. UDFF was positively correlated with the severity of MAFLD (r = 0.603, P < 0.01). The AUC of SWE for diagnosing MAFLD was 0.728, with sensitivity, specificity, and cut-off values of 51.6, 93.3%, and 1.015 m/s, respectively. SWV was negatively correlated with the severity of MAFLD (r = - 0.551, P < 0.01).

CONCLUSION

The prevalence of MAFLD is significantly higher in obese PCOS patients, and UDFF technology can detect and quantitatively analyze liver fat infiltration in obese PCOS patients early. At the same time, auto-pSWE also has diagnostic significance for the progression of liver disease.

Comparison of the diagnostic accuracy of shear wave elastography with transient elastography in adult nonalcoholic fatty liver disease: a systematic review and network meta-analysis of diagnostic test accuracy

PURPOSE

To compare the diagnostic test accuracy (DTA) of shear wave elastography (SWE) to that of transient elastography (TE) for liver fibrosis grade assessment in nonalcoholic fatty liver disease adults.

METHODS

MEDLINE, The Cochrane Library, and Web of Science were searched. Inclusion criteria were primary studies examining DTA of TE, point SWE (pSWE), two-dimensional SWE (2D-SWE), or magnetic resonance elastography (MRE) with liver biopsy. Network meta-analysis was conducted using a Bayesian bivariate mixed-effects model.

RESULTS

For fibrosis grade 2 or higher, 15 studies with 25 observations (16 observations for TE, 1 for MRE, 4 for pSWE and 2D-SWE; 2,066 patients) were included; the pooled sensitivity and specificity were 0.79 (95% credible interval (CrI) 0.70-0.86; 95% prediction interval (PI) 0.36-0.96) and 0.73 (95% CrI 0.62-0.82; 95% PI 0.23-0.96) for TE, 0.68 (95% CrI 0.48-0.83; 95% PI 0.23-0.94) and 0.75 (95% CrI 0.53-0.88; 95% PI 0.24-0.97) for pSWE, 0.85 (95% CrI 0.70-0.93; 95% PI 0.40-0.98) and 0.72 (95% CrI 0.49-0.86; 95% PI 0.20-0.96) for 2D-SWE, respectively. The proportion of studies classified as unclear in QUADAS-2 was high, and the results were heterogeneous.

CONCLUSION

2D-SWE could be recommended as TE is for liver fibrosis assessment. The protocol of this systematic review and network meta-analysis has been registered in PROSPERO (CRD42022327249). All included primary papers have already been published and the information and data can be used freely.

Optimal cut-offs of vibration-controlled transient elastography and magnetic resonance elastography in diagnosing advanced liver fibrosis in patients with nonalcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND/AIMS

Opinions differ regarding vibration-controlled transient elastography and magnetic resonance elastography (VCTE/MRE) cut-offs for diagnosing advanced fibrosis (AF) in patients with non-alcoholic fatty liver disease (NAFLD). We investigated the diagnostic performance and optimal cut-off values of VCTE and MRE for diagnosing AF.

METHODS

Literature databases, including Medline, EMBASE, Cochrane Library, and KoreaMed, were used to identify relevant studies published up to June 13, 2023. We selected studies evaluating VCTE and MRE regarding the degree of liver fibrosis using liver biopsy as the reference. The sensitivity, specificity, and area under receiver operating characteristics curves (AUCs) of the pooled data for VCTE and MRE for each fibrosis stage and optimal cut-offs for AF were investigated.

RESULTS

A total of 19,199 patients from 63 studies using VCTE showed diagnostic AUC of 0.83 (95% confidence interval: 0.80-0.86), 0.83 (0.80-0.86), 0.87 (0.84-0.90), and 0.94 (0.91-0.96) for ≥F1, ≥F2, ≥F3, and F4 stages, respectively. Similarly, 1,484 patients from 14 studies using MRE showed diagnostic AUC of 0.89 (0.86-0.92), 0.92 (0.89-0.94), 0.89 (0.86-0.92), and 0.94 (0.91-0.96) for ≥F1, ≥F2, ≥F3, and F4 stages, respectively. The diagnostic AUC for AF using VCTE was highest at 0.90 with a cut-off of 7.1-7.9 kPa, and that of MRE was highest at 0.94 with a cut-off of 3.62-3.8 kPa.

CONCLUSION

VCTE (7.1-7.9 kPa) and MRE (3.62-3.8 kPa) with the suggested cut-offs showed favorable accuracy for diagnosing AF in patients with NAFLD. This result will serve as a basis for clinical guidelines for non-invasive tests and differential diagnosis of AF.

New microvascular ultrasound techniques: abdominal applications

Microvascular ultrasound (MVUS) is a new ultrasound technique that allows the detection of slow-velocity flow, providing the visualization of the blood flow in small vessels without the need of intravenous contrast agent administration. This technology has been integrated in the most recent ultrasound equipment and applied for the assessment of vascularization. Compared to conventional color Doppler and power Doppler imaging, MVUS provides higher capability to detect intralesional flow. A growing number of studies explored the potential applications in hepatobiliary, genitourinary, and vascular pathologies. Different flow patterns can be observed in hepatic and renal focal lesions providing information on tumor vascularity and improving the differential diagnosis. This article aims to provide a detailed review on the current evidences and applications of MVUS in abdominal imaging.

Liver Ultrasound Elastography in Non-Alcoholic Fatty Liver Disease: A State-of-the-Art Summary

Non-alcoholic fatty liver disease (NAFLD) is a chronic disease which is currently the most common hepatic disorder affecting up to 38% of the general population with differences according to age, country, ethnicity and sex. Both genetic and acquired risk factors such as a high-calorie diet or high intake of saturated fats have been associated with obesity, diabetes and, finally, NAFLD. A liver biopsy has always been considered essential for the diagnosis of NAFLD; however, due to several limitations such as the potential occurrence of major complications, sampling variability and the poor repeatability in clinical practice, it is considered an imperfect option for the evaluation of liver fibrosis over time. For these reasons, a non-invasive assessment by serum biomarkers and the quantification of liver stiffness is becoming the new frontier in the management of patients with NAFLD and liver fibrosis. We present a state-of-the-art summary addressing the methods for the non-invasive evaluation of liver fibrosis in NAFLD patients, particularly the ultrasound-based techniques (transient elastography, ARFI techniques and strain elastography) and their optimal cut-off values for the staging of liver fibrosis.

Accuracy of Ultrasonography vs. Elastography in Patients With Non-alcoholic Fatty Liver Disease: A Systematic Review

Ultrasonography and elastography are the most widely used imaging modalities for diagnosing non-alcoholic fatty liver disease. This study aimed to assess and compare the diagnostic accuracy in patients with non-alcoholic fatty liver disease/non-alcoholic steatohepatitis. This systematic review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search was done for the past seven years using Pubmed, Pubmed Central, Cochrane, and Google Scholar databases on Jun 29, 2022. Studies were included based on the following predefined criteria: observational studies, randomized controlled trial (RCT), comparative studies, studies using liver biopsy or MRI proton density fat fraction (MRI PDFF) as a reference standard, ultrasonography, and elastography with measures of their diagnostic accuracy like sensitivity (SN), specificity (SP), area under the receiver operating characteristic (AUROC) curve, and English language. The data were extracted on a predefined template. The final twelve eligible studies were assessed using the quality assessment of diagnostic accuracy tool (QUADS-2). Most studies focused on elastography techniques, and the remaining focused on quantitative ultrasonography methods like the controlled attenuation parameter (CAP) and attenuation coefficient (AC). Only one study was available for the evaluation of qualitative ultrasonography. MRI was generally found superior to other diagnostic tests for determining liver stiffness through magnetic resonance elastography (MRE) and steatosis through MRI PDFF. Data assessing the comparative diagnostic accuracy of the two tests were inconclusive.

New horizon of ultrasound for screening and surveillance of non-alcoholic fatty liver disease spectrum

Non-alcoholic fatty liver disease (NAFLD) affects almost one quarter of adults worldwide, and its progressive subtype, non-alcoholic steatohepatitis can progress to advanced fibrosis/cirrhosis and even hepatocellular carcinoma. It is critical to screen and grade NAFLD patients for management decisions to rationalize the utilization of medical resources. Conventional ultrasound is widely applied for NAFLD screening, however, some inherent weaknesses hinder its utility. This limitation has spurred the development of acoustic parameters-based quantitative ultrasound techniques that allow a more accurate evaluation of the histological features of NAFLD (e.g. steatosis, necroinflammation, fibrosis/cirrhosis). Herein, this paper reviews the research advances in emerging ultrasound techniques for screening and surveillance across NAFLD spectrum and summarize their principles, feasibility, accuracy, reproducibility, and limitations of each technique. The challenges and future directions are also discussed to advance clinical practice.

Accuracy of controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) for assessing steatosis and fibrosis in non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease, and among the non-invasive tests, controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) have shown better diagnostic performance in NAFLD. This meta-analysis aimed to evaluate the performance of CAP and LSM for assessing steatosis and fibrosis in NAFLD.

METHODS

We searched the PubMed, Web of Science, Cochrane Library, and Embase databases for relevant articles published up to February 13^th, 2022, and selected studies that met the inclusion and exclusion criteria, and evaluated the quality of evidence. Then we pooled sensitivity (SE), specificity (SP), and area under receiver operating characteristic (AUROC) curves. A random effect model was applied regardless of heterogeneity. Meta-regression analysis and subgroup analysis were performed to explore heterogeneity, and Fagan plot analysis was used to evaluate clinical utility. This meta-analysis was completed in Nanjing, Jiangsu and registered on PROSPERO (CRD42022309965).

FINDINGS

A total of 10537 patients from 61 studies were included in our meta-analysis. The AUROC of CAP were 0·924, 0·794 and 0·778 for steatosis grades ≥ S1, ≥ S2 and = S3, respectively, and the AUROC of LSM for detecting fibrosis stages ≥ F1, ≥ F2, ≥ F3, and = F4 were 0·851, 0·830, 0·897 and 0·925, respectively. Subgroup analysis revealed that BMI ≥ 30 kg/m² had lower accuracy for diagnosing S ≥ S1, ≥ S2 than BMI<30 kg/m². For the mean cut-off values, significant differences were found in CAP values among different body mass index (BMI) populations and LSM values among different regions. For diagnosing S ≥ S1, ≥ S2 and = S3, the mean CAP cut-off values for BMI ≥ 30 kg/m² were 30·7, 28·2, and 27·9 dB/m higher than for BMI < 30 kg/m² (P = 0·001, 0·001 and 0·018, respectively). For diagnosing F ≥ F2 and = F4, the mean cut-off values of Europe and America were 0·96 and 2·03 kPa higher than Asia (P = 0·027, P = 0·034), respectively. In addition, the results did not change significantly after sensitivity analysis and the trim and fill method to correct for publication bias, proving that the conclusions are robust.

INTERPRETATION

The good performance of CAP and LSM for the diagnosis of mild steatosis (S ≥ S1), advanced liver fibrosis (F ≥ F3), and cirrhosis (F = F4) can be used to screen for NAFLD in high-risk populations. Of note, the accuracy of CAP for the detection of steatosis in patients with obesity is reduced and requires specific diagnostic values. For LSM, the same diagnostic values can be used when the appropriate probes are selected based on BMI and the automated probe selection tool. The performance of CAP and LSM in assessing steatosis in patients with obesity, moderate to severe steatosis, and low-grade fibrosis should be further validated and improved in the future.

FUNDING

The study was funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).

Focal liver lesions in cirrhosis: Role of contrast-enhanced ultrasonography

Contrast-enhanced ultrasound (CEUS) represents a great innovation for the evaluation of focal liver lesions (FLLs). The main advantage of CEUS is the real-time imaging examination and the very low toxicity in patients with renal failure. Liver cirrhosis has been recognized as a major risk factor for the onset of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (ICC). HCC in liver cirrhosis develops as the last step of a complex that leads to the gradual transformation from regenerative nodule through dysplastic nodule to HCC. In patients with liver cirrhosis, a surveillance program is recommended consisting of ultrasound (US) for detecting small focal lesions. A wide spectrum of benign and malignant lesions other than HCC may be found in the cirrhotic liver and their differentiation is important to avoid errors in staging diseases that may preclude potentially curative therapies. Several published studies have explored the value of CEUS in liver cirrhosis and they have been shown to have excellent diagnostic and prognostic performances for the evaluation of non-invasive and efficient diagnosis of FLLs in patients at high risk for liver malignancies. The purpose of this article is to describe and discuss CEUS imaging findings of FLLs including HCC and ICC, all of which occur in cirrhotic livers with varying prevalence.

Comparison of superb microvascular imaging and shear wave elastography for assessing liver fibrosis in chronic hepatitis B

Purpose

The present study investigated the effectiveness and applicability of superb microvascular imaging (SMI) in determining the degree of liver fibrosis noninvasively in comparison with shear wave elastography (SWE).

Methods

Ninety-eight consecutive patients with chronic hepatitis B who underwent ultrasound (US)-guided needle biopsy were examined using US combined with SMI and SWE. The predictive performance of the two US techniques in staging liver fibrosis and inflammation was compared with reference to the histological findings obtained from liver biopsy. The intraobserver and interobserver reproducibility of SMI in vascularity scores were evaluated.

Results

SWE values and SMI vascular scores were statistically significantly different among fibrosis stages (χ²(3)=76.3, χ²(3)=81.5, P<0.001). The SWE and SMI models significantly predicted fibrosis stages separately, and SMI scores alone predicted fibrosis stages better than SWE values (50.1% for SWE, 63.5% for SMI, P<0.001). A model with both SMI scores and SWE values together explained 73.2% of variance in fibrosis stages. When other clinical and laboratory predictors were added to the model (81.5%, P<0.001), SWE values and SMI scores remained the main predictors of fibrosis stages. SWE and SMI were also applicable in predicting inflammatory grades, explaining 31% and 34% of variance, respectively, and 37.7% when used together (P<0.001).

Conclusion

Both SWE and SMI had good diagnostic performance in determining the degree of liver fibrosis in chronic hepatitis B patients. The efficacy of SMI was better than that of SWE. SMI can improve diagnostic performance for staging liver fibrosis and shows potential for estimating necroinflammation of the liver.

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.

Clinical predictive score for detecting nonalcoholic fatty liver disease with significant fibrosis in patients with metabolic syndrome

Patients with metabolic syndrome are at a higher risk of nonalcoholic fatty liver disease (NAFLD) and liver fibrosis than the general population. Still, accessibility of screening method for NAFLD with significant fibrosis, such as transient elastography (FibroScan) are limited in some settings. This study aimed to develop a simple clinical predictive score for detecting NAFLD with significant fibrosis in patients with metabolic syndrome.A cross-sectional study was designed to obtain the data from medical records of all relevant patients who underwent transient elastography between January 2011 and December 2020 at Siriraj Hospital, Thailand. A liver stiffness cutoff value of 7.0 kilopascal was used to define the presence of significant liver fibrosis. To examine potential predictors, medical history and clinical data commonly assessed in routine practice were selected by following expert opinions and univariable statistical analysis. Backward and forward stepwise logistic regression was performed to acquire a final prediction model. To simplify the model, a weighted score was assigned for each categorized predictor. In addition, eligible cutoff values of the score and their predictive performances were determined.A total of 745 medical records were reviewed. The prevalence of NAFLD with significant fibrosis in patients with metabolic syndrome was 12.6%. Most clinical characteristics of patients with NAFLD with significant fibrosis and those non-NAFLD and NAFLD with no/mild fibrosis were quite disparate. The most practical model comprised globulin, aspartate transaminase, platelet count, and type 2 diabetes. It provided a good predictive performance with an area under the receiver operating characteristic curve of 0.828 (95% confidence interval [CI]: 0.782, 0.874). At the proper cutoff value, sensitivity and specificity were 76.6% (95% CI: 66.7%, 84.7%) and 72.4% (95% CI: 68.7%, 75.8%), respectively. The likelihood ratio of testing positive for NAFLD with significant fibrosis was 2.8 (95% CI: 2.34, 3.27) among patients with scores above the cutoff value.The first score for detecting of NAFLD with significant fibrosis in patients with metabolic syndrome was developed. This practical score, providing a good predictive performance, should be useful to help clinicians prioritize needs for further investigations among high-risk patients, especially in resource-limited settings.

Diagnostic accuracy of two-dimensional shear wave elastography and transient elastography in nonalcoholic fatty liver disease

INTRODUCTION

Two-dimensional shear wave elastography (2D-SWE) and vibration-controlled transient elastography (VCTE) provide noninvasive assessment of hepatic fibrosis. We compared performance of 2D-SWE and VCTE for fibrosis detection in nonalcoholic fatty liver disease (NAFLD).

METHODS

We performed a prospective study of adults with NAFLD who underwent 2D-SWE, VCTE, and liver biopsy analysis (using Nonalcoholic Steatohepatitis Clinical Research Network scoring system). The primary outcome was hepatic fibrosis (stage ⩾ 1); secondary outcomes included dichotomized fibrosis stages. Area under receiver operating characteristic curve (AUROC) analyses were used to compare 2D-SWE and VCTE performance.

RESULTS

A total of 114 adults with a median BMI of 31.2 kg/m² were included. The VCTE was better than 2D-SWE for the detection of fibrosis (AUROC: 0.81 versus 0.72, p = 0.03). The VCTE detected fibrosis stage 2, 3, or 4 with AUROCs of 0.86 (95% CI, 0.80-0.93), 0.91 (95% CI, 0.82-0.99), and 0.96 (95% CI, 0.91-1.00). The 2D-SWE detected fibrosis stage 2, 3, or 4 with AUROCs of 0.84 (95% CI, 0.76-0.92), 0.88 (95% CI, 0.81-0.96), and 0.93 (95% CI, 0.86-0.99).

CONCLUSION

In a prospective study including more than 100 adults with NAFLD, we found VCTE to be more accurate than 2D-SWE in detecting fibrosis; these modalities, however, are comparable in assessing for higher stages of fibrosis.

Non-alcoholic fatty liver disease, insulin resistance, metabolic syndrome and their association with vascular risk

The prevalence of non-alcoholic fatty liver disease (NAFLD), one of the most common liver diseases, is rising. About 25% of adults worldwide are probably affected by NAFLD. Insulin resistance (IR) and fat accumulation in the liver are strongly related. The association between NAFLD, metabolic syndrome (MetS) and IR is established, but an independent impact of NAFLD on vascular risk and progression of cardiovascular (CV) disease (CVD) still needs to be confirmed. This narrative review considers the evidence regarding the link between NAFLD, IR and CVD risk. There is strong evidence for a "concomitantly rising incidence" of NAFLD, IR, MetS and CVD but there is no definitive evidence regarding whether NAFLD is, or is not, an independent and significant risk factor the development of CVD. There are also considerations that type 2 diabetes mellitus (T2DM) may be a common link between NAFLD/non-alcoholic steatohepatitis (NASH) and CVD. NAFLD may be associated with widespread abnormal peri-organ or intra-organ fat (APIFat) deposition (e.g. epicardial adipose tissue) which may further contribute to CV risk. It is clear that NAFLD patients have a greater CV risk (independent or not) which needs to be addressed in clinical practice.