Value of shear wave elastography for predicting hepatocellular carcinoma and esophagogastric varices in patients with chronic liver disease

Doppler hemodynamic liver index and hepatic elastic modulus: Advanced ultrasonographic techniques for non-invasive prediction of esophageal varices in cirrhosis

PURPOSE

Currently esophagoscopy is the gold standard for assessment of esophageal varices in cirrhosis. Predicting the presence of esophageal varices, varices needing treatment (VNT) and variceal grade by advanced ultrasonographic techniques using a combination of Doppler hemodynamic liver index (HDLI) (quantifying portal hypertension) and hepatic elastic modulus (quantifying hepatic fibrosis) would be a cost-effective and non-invasive alternative to routine endoscopy.

METHODS

Our cross-sectional study consisted of cirrhotic patients diagnosed using clinical features and laboratory parameters. Portal venous Doppler and liver sonoelastography were performed in selected subjects for obtaining measurements of HDLI (portal vein diameter/mean velocity) and hepatic elastic modulus respectively. Within 3 days of ultrasound, the subjects underwent upper GI endoscopy for assessment of presence, VNT and grade (F1, F2, F3) of varices. Subjects were divided into two groups (without and with varices) and data analyzed using XLSTAT.

RESULTS

A total of 60 subjects (26 without and 34 with varices) were evaluated. Mean Doppler HDLI of subjects with varices was significantly higher (0.72 vs. 0.59, p < 0.0001) with progressive increase in values with variceal grade, being highest in grade-F3 (mean 0.77). Likewise, mean hepatic elastic modulus was also higher in subjects with varices (28.9 vs. 12.6 kPa, p < 0.0001) and showed progressive increase with grade (51.1 kPa for F3). For predicting presence of varices, maximum accuracy of elastic modulus was at cut-off of 14.5 kPa (sensitivity, specificity 83% and 84.6%) and Doppler HDLI was at 0.66 (66% and 92.3%). Good inter-rater agreement was present (κ 0.66).

CONCLUSION

Combination of Doppler HDLI and hepatic elastic modulus is an excellent non-invasive method for predicting the presence, VNT, and variceal grade and may obviate need for routine endoscopic screening in cirrhosis.

Liver Elastography as a Predictor of Esophageal Varices in Patients With Cirrhosis

Introduction

Liver cirrhosis is an advanced consequence of a long-standing liver disease that can lead to portal hypertension which subsequently can manifest as life-threatening variceal bleeding. The present study aimed to determine liver stiffness by shear wave elastography (SWE) to predict esophageal varices (EV) in patients with chronic liver diseases.

Methodology

A prospective observational study was performed at the Department of Hepatogastroenterology, Sindh Institute of Urology and Transplantation, Karachi between November 2020 and July 2021. Individuals aged between 18 and 50 years, irrespective of gender, with diagnosed chronic liver disease >6 months were eligible to partake in the study. Patients with concomitant renal failure, severe ascites, severe life-threatening co-morbidities including congestive heart failure NYHA-III and IV, acute asthmatic attack, and recent myocardial infarction (MI) were excluded from the study. SWE was determined in all patients to measure liver stiffness. Esophagogastroduodenoscopy (EGD) was performed to visualize the esophageal varices. All findings were recorded. A 2 × 2 table was applied to determine the sensitivity, specificity, positive, and diagnostic accuracy for SWE by taking endoscopy as the definitive test.

Results

A total of 204 patients were included in the study. Mean age of 40.37 ± 15.20 years was observed. The mean liver size of patients was 12.38 ± 2.06 cm and the mean liver stiffness of patients was 19.97 ± 8.6. The sensitivity and specificity of liver elastography were 44.90% and 51.90%, respectively. Furthermore, the positive and negative predictive values were 53.00% and 99.39%, respectively. The diagnostic accuracy of the test was 51.86%.

Conclusion

Even though the diagnostic gold standard for the detection of varices is EGD, liver elastography provides a less invasive procedure to assess for varices in patients with cirrhotic liver disease. The present study concluded that liver elastography is a non-invasive and indirect valuable tool to predict the presence of esophageal varices with sensitivity and specificity of 44.90% and 51.90%, respectively.

Noninvasive Detection of Clinically Significant Portal Hypertension in Compensated Advanced Chronic Liver Disease

Patients with compensated advanced chronic liver disease have different prognoses depending on the presence of portal hypertension. Current non-invasive diagnostic methods allow identification of clinically significant portal hypertension. Portosystemic collaterals on imaging or liver stiffness of more than 20 to 25 kPa by using transient elastography identifies patients with clinically significant portal hypertension. Patients with liver stiffness of less than 20 kPa and platelet count of greater than 150 g/L can avoid endoscopy. This rule could be expanded using spleen stiffness. Methods to risk stratify for portal hypertension in compensated advanced chronic liver disease and successfully treated chronic hepatitis C and B are subject of research.

Evaluation of therapeutic effect of targeting nanobubbles conjugated with NET-1 siRNA by shear wave elastography: an in vivo study of hepatocellular carcinoma bearing mice model

This study aimed at investigating the tumor stiffness of hepatocellular carcinoma (HCC) bearing mice model in vivo to evaluate the therapeutic efficacy of targeting nanobubbles (TNBS) conjugated with NET-1 siRNA (NET-1 siRNA-TNBS). Also tested whether shear wave elastography (SWE) could demonstrate the pathological tumor changes and used to monitor therapeutic efficacy as a noninvasive method. The HCC bearing mice model was established by injecting human HCC cell line (HepG2). The mice were then divided into three groups randomly, and were treated with TNBS conjugated with NET-1 siRNA, TNBS conjugated with negative control gene, and saline as control. US-SWE was performed for three times. SWE values of all the tumors in three groups were increased with tumor growth. Emax was correlated with tumor size (p < .05). NET-1 gene (treatment group) significantly delayed the growth of tumor size compared to other two groups (p < .0001), showing a significantly increased Emax (p < .05). Immunohistochemical results showed that the NET-1 protein expression was significantly lower than the negative control and blank groups. In conclusion, TNBS conjugated with NET-1 siRNA inhibited tumor growth and prolonged the life of experimental animals. SWE provided a noninvasive and real time imaging method to detect the changes in tumor development.

Liver fibrosis imaging: A clinical review of ultrasound and magnetic resonance elastography

Liver fibrosis is a histological hallmark of most chronic liver diseases, which can progress to cirrhosis and liver failure, and predisposes to hepatocellular carcinoma. Accurate diagnosis of liver fibrosis is necessary for prognosis, risk stratification, and treatment decision-making. Liver biopsy, the reference standard for assessing liver fibrosis, is invasive, costly, and impractical for surveillance and treatment response monitoring. Elastography offers a noninvasive, objective, and quantitative alternative to liver biopsy. This article discusses the need for noninvasive assessment of liver fibrosis and reviews the comparative advantages and limitations of ultrasound and magnetic resonance elastography techniques with respect to their basic concepts, acquisition, processing, and diagnostic performance. Variations in clinical contexts of use and common pitfalls associated with each technique are considered. In addition, current challenges and future directions to improve the diagnostic accuracy and clinical utility of elastography techniques are discussed. Level of Evidence: 5 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2020;51:25-42.

Liver stiffness measurement changes following hepatocellular carcinoma treatment with percutaneous microwave ablation or transarterial chemoembolization: a cohort study

BACKGROUND

Liver stiffness increases after the development of hepatocellular carcinoma (HCC). Transient elastography for liver stiffness measurement (LSM) using fibroscan is a simple noninvasive method of proven efficacy. This study aims to assess the changes in LSM following HCC treatment.

PATIENTS AND METHODS

This study included 150 patients with hepatitis C virus related HCC attending the multidisciplinary HCC clinic, Kasr Al-Ainy Hospital between March 2014 and October 2015 who underwent either transarterial chemoembolization (TACE) or microwave ablation (MWA). Baseline LSM was carried out 3 and 6 months after treatment. The response rate was calculated according to the modified Response Evaluation Criteria in Solid Tumors criteria; overall survival and LSM changes were then compared between the two procedures.

RESULTS

MWA showed higher rates of complete ablation (77.4%) than did TACE (31.7%) (P=0.004). Increase in LSM 3 and 6 months after treatment was statistically significant in the TACE group (P<0.001) but not in the MWA group (P=0.4). Patients who showed complete ablation had statistically significant lower baseline LSM than those with incomplete ablation, and their 6 months increase in LSM was also significantly lower. Logistic regression revealed that with each unit increase in baseline stiffness, 3% reduction in the odds of complete ablation is expected, and this did not change after controlling for the type of treatment. Child-Pugh class, number, and size of HCCs were our independent prognostic factors by Cox proportional analysis.

CONCLUSION

The increase in LSM is significant after TACE than after MWA. Moreover, lower pre-ablation LSM is a predictor of complete ablation.

Comparative Diagnostic Accuracy of Contrast-Enhanced Ultrasound and Shear Wave Elastography in Differentiating Benign and Malignant Lesions: A Network Meta-Analysis

Background: We performed a network meta-analysis to compare the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) and shear wave elastography (SWE) in differentiating benign and malignant lesions in different body sites.

Methods: A computerized literature search of Medline, Embase, SCOPUS, and Web of Science was performed using relevant keywords. Following data extraction, we calculated sensitivity, specificity, positive likelihood ratio (LR), negative LR, and diagnostic odds ratio (DOR) for CEUS, and SWE compared to histopathology as a reference standard. Statistical analyses were conducted by MetaDiSc (version 1.4) and R software (version 3.4.3).

Results: One hundred and fourteen studies (15,926 patients) were pooled in the final analyses. Network meta-analysis showed that CEUS had significantly higher DOR than SWE (DOR = 27.14, 95%CI [2.30, 51.97]) in breast cancer detection. However, there were no significant differences between CEUS and SWE in hepatic (DOR = −6.67, 95%CI [−15.08, 1.74]) and thyroid cancer detection (DOR = 3.79, 95%CI [−3.10, 10.68]). Interestingly, ranking analysis showed that CEUS achieved higher DOR in detecting breast and thyroid cancer, while SWE achieved higher DOR in detecting hepatic cancer. The overall DOR for CEUS in detecting renal cancer was 53.44, 95%CI [29.89, 95.56] with an AUROC of 0.95, while the overall DOR for SWE in detecting prostate cancer was 25.35, 95%CI [7.15, 89.89] with an AUROC of 0.89.

Conclusion: Both diagnostic tests showed relatively high sensitivity and specificity in detecting malignant tumors in different organs. Network meta-analysis showed that CEUS had higher diagnostic accuracy than SWE in detecting breast and thyroid cancer, while SWE had higher accuracy in detecting hepatic cancer. However, the results were not statistically significant in hepatic and thyroid malignancies. Further head-to-head comparisons are needed to confirm the optimal imaging technique to differentiate each cancer type.

Elastography-based screening for esophageal varices in patients with advanced chronic liver disease

Elastography-based liver stiffness measurement (LSM) is a non-invasive tool for estimating liver fibrosis but also provides an estimate for the severity of portal hypertension in patients with advanced chronic liver disease (ACLD). The presence of varices and especially of varices needing treatment (VNT) indicates distinct prognostic stages in patients with compensated ACLD (cACLD). The Baveno VI guidelines suggested a simple algorithm based on LSM < 20 kPa (by transient elastography, TE) and platelet count > 150 G/L for ruling-out VNT in patients with cACLD. These (and other) TE-based LSM cut-offs have been evaluated for VNT screening in different liver disease etiologies. Novel point shear-wave elastography (pSWE) and two-dimensional shear wave elastography (2D-SWE) methodologies for LSM have also been evaluated for their ability to screen for “any” varices and for VNT. Finally, the measurement of spleen stiffness (SSM) by elastography (mainly by pSWE and 2D-SWE) may represent another valuable screening tool for varices. Here, we summarize the current literature on elastography-based prediction of “any” varices and VNT. Finally, we have summarized the published LSM and SSM cut-offs in clinically useful scale cards.

VTIQ evaluates antitumor effects of NET-1 siRNA by UTMD in HCC xenograft models

The present study used a virtual touch tissue imaging and quantification (VTIQ) method to investigate the change in elasticity in xenograft tumor tissue models following silencing of the neuroepithelial-transforming protein 1 (NET-1) gene by ultrasound-targeted microbubble destruction (UTMD). A total of 24 xenograft models were established by subcutaneous injection of human hepatocellular carcinoma SMMC-7721 cells in BALB/c female nude mice. Then, NET-1 small interfering RNA (siRNA)-conjugated nanobubbles and a glypican-3 antibody were synthesized. The mean and maximum shear wave speed (SWS_mean and SWS_max) in the tumor tissue were measured prior to, during, and following therapy using VTIQ. The growth of the tumor size and survival time were recorded. The levels of NET-1 protein were evaluated by immunohistochemical staining. In addition, tumor, liver and kidney tissues of the nude mice were collected to confirm whether gene transfection treatment was toxic in vivo. In the UTMD delivery gene group, SWS_mean was correlated with the maximum diameter of the tumor (r=0.9806, P=0.0194). The immunohistochemical staining data indicated that the level of NET-1 protein in the treated groups was significantly decreased compared with those in the control groups. Additionally, no structural damage was observed in the nude mice liver and kidney tissues following treatment. Therefore, VTIQ measurement identified potential changes in the elastic properties of the tumors, which in turn may be associated with the stages of tumor development. The delivery method, UTMD, improves the antitumor effects of NET-1 siRNA and supports gene transfection as a promising therapeutic strategy.

Νon-invasive screening for esophageal varices in patients with liver cirrhosis

Esophageal varices are one of the main complications of liver cirrhosis. Upper gastrointestinal endoscopy is the gold standard for the detection of esophageal varices. Many less invasive methods for screening of varices have been investigated and the most recent Baveno VI guidelines suggest that endoscopy is not necessary in patients with liver stiffness <20 kPa and platelets >150,000/μL. A critical review of the literature was performed concerning non-invasive or minimally invasive methods of screening for esophageal varices. Liver and spleen elastography, imaging methods including computed tomography, magnetic resonance imaging and ultrasound, laboratory tests and capsule endoscopy are discussed. The accuracy of each method, and its advantages and limitations compared to endoscopy are analyzed. There are data to support the Baveno VI guidelines, but there is still a lack of large prospective studies and low specificity has been reported for the liver stiffness and platelet count combination. Spleen elastography has shown promising results, as there are data to support its superiority to liver elastography, but it needs further assessment. Computed tomography has shown high diagnostic accuracy and can be part of the diagnostic work up of cirrhotic patients in the future, including screening for varices.

Quantitative Elastography Methods in Liver Disease: Current Evidence and Future Directions

Chronic liver diseases often result in the development of liver fibrosis and ultimately, cirrhosis. Treatment strategies and prognosis differ greatly depending on the severity of liver fibrosis, thus liver fibrosis staging is clinically relevant. Traditionally, liver biopsy has been the method of choice for fibrosis evaluation. Because of liver biopsy limitations, noninvasive methods have become a key research interest in the field. Elastography enables the noninvasive measurement of tissue mechanical properties through observation of shear-wave propagation in the tissue of interest. Increasing fibrosis stage is associated with increased liver stiffness, providing a discriminatory feature that can be exploited by elastographic methods. Ultrasonographic (US) and magnetic resonance (MR) imaging elastographic methods are commercially available, each with their respective strengths and limitations. Here, the authors review the technical basis, acquisition techniques, and results and limitations of US- and MR-based elastography techniques. Diagnostic performance in the most common etiologies of chronic liver disease will be presented. Reliability, reproducibility, failure rate, and emerging advances will be discussed. ^© RSNA, 2018 Online supplemental material is available for this article.

Quantitative and noninvasive assessment of chronic liver diseases using two-dimensional shear wave elastography

Two-dimensional shear wave elastography (2D-SWE) is a rapid, simple and novel noninvasive method that has been proposed for assessing hepatic fibrosis in patients with chronic liver diseases (CLDs) based on measurements of liver stiffness. 2D-SWE can be performed easily at the bedside or in an outpatient clinic and yields immediate results with good reproducibility. Furthermore, 2D-SWE was an efficient method for evaluating liver fibrosis in small to moderately sized clinical trials. However, the quality criteria for the staging of liver fibrosis are not yet well defined. Liver fibrosis is the main pathological basis of liver stiffness and a key step in the progression from CLD to cirrhosis; thus, the management of CLD largely depends on the extent and progression of liver fibrosis. 2D-SWE appears to be an excellent tool for the early detection of cirrhosis and may have prognostic value in this context. Because 2D-SWE has high patient acceptance, it could be useful for monitoring fibrosis progression and regression in individual cases. However, multicenter data are needed to support its use. This study reviews the current status and future perspectives of 2D-SWE for assessments of liver fibrosis and discusses the technical advantages and limitations that impact its effective and rational clinical use.

Reliability and applicability of two-dimensional shear-wave elastography for the evaluation of liver stiffness

BACKGROUND/AIM

Two-dimensional shear-wave elastography (2D-SWE) is a new elastographic technique that is increasingly being used across several indications. We assessed the reliability and applicability of 2D-SWE in patients with various chronic liver diseases and attempted to identify parameters potentially affecting liver stiffness.

METHODS

We included all patients with chronic liver disease who underwent 2D-SWE examination over a 15-month period. Patients with acute hepatitis, active cholestatic disease, or severe heart failure were excluded. The procedures were performed by three adequately trained operators. Standard operating procedures for liver ultrasonography and elastography were followed.

RESULTS

2D-SWE was reliable in 98% of 605 patients. SD to mean liver stiffness value ratio greater than 9.14%, which was considered an indicator of reliability, was associated independently with age more than 50 years, obesity, or overweight, and use of statins for hyperlipidemia. 2D-SWE was applicable, requiring a median time of 7 min per examination and exceeding 15 min in only 5.5% of patients. Worse applicability expressed as duration more than 0.7 min per reliable measurement was associated independently with age more than 50 years and obesity. The mean and median liver stiffness values were 11.6 and 7.7 kPa, respectively. Liver stiffness more than 7.7 kPa was associated independently with age more than 50 years and increased waist circumference.

CONCLUSION

2D-SWE represents an applicable method of assessment of liver fibrosis that can provide reliable results in the vast majority of patients with chronic liver diseases. Older age and obesity may affect the reliability and applicability of the method as well as the severity of liver fibrosis.