Liver and spleen stiffness measured by acoustic radiation force impulse elastography for noninvasive assessment of liver fibrosis and esophageal varices in patients with chronic hepatitis B

Evaluation of liver and splenic stiffness by acoustic radiation force impulse for assessment of esophageal varices

BACKGROUND

In routine clinical practice, assessment of portal hypertension (PHT) among patients with liver cirrhosis is done by a upper gastrointestinal endoscopy (UGIE); however, its invasive nature limits its use. Recent advances in ultrasound imaging make it possible to evaluate the tissue stiffness of the liver and spleen reflecting the severity of underlying fibrosis. Liver stiffness and spleen stiffness can be used to predict the presence of esophageal varices/PHT among cirrhotic patients.

AIM

To predict the presence or absence of esophageal varices by measuring the stiffness of the liver and spleen by ultrasonography (USG)-based acoustic radiation force impulse (ARFI).

METHODS

This cross-sectional study included 90 subjects with liver cirrhosis. Liver and splenic stiffness were measured along with the USG abdomen, UGIE and aspartate aminotransferase to platelet ratio index (APRI).

RESULTS

Liver and spleen stiffness were significantly higher in cirrhotic patients compared to chronic hepatitis B. The best cut-off value of liver stiffness (LS) obtained by the receiver operating characteristic (ROC) curve was 2.16 m/s for predicting esophageal varices (AUROC 0.78, p 0.0002). The best cut-off value of splenic stiffness (SS) obtained by the ROC curve was 3.04 m/s for predicting esophageal varices (AUROC 0.698, p 0.0274). When both LS and SS were taken together, the accuracy in predicting esophageal varices increased to 92.22%. An equation to predict "esophageal varices = (0.225 LS + 0.377SS) - 0.555" was derived.

CONCLUSION

LS and SS values of ≥ 2.16 m/s and 3.04 m/s, respectively, predict esophageal varices independently; however, combined assessment is better with 92% accuracy.

Point-shear wave elastography generated by acoustic radiation force impulse in chronic pancreatitis

BACKGROUND

Transcutaneous point-shear wave elastography (p-SWE) performed using an acoustic radiation force impulse can be used to quantify pancreatic stiffness in chronic pancreatitis (CP). We aimed to evaluate its usefulness to diagnose and monitor CP.

METHODS

175 participants were included in this prospective study including patients with CP (n = 65), liver cirrhosis (LC; n = 60), alcohol abuse (n = 10) and healthy controls (n = 40). Point-shear wave elastography of the pancreas was performed and quantified as median shear wave velocity (SWV). In the same way, p-SWE of the spleen served as a marker of portal hypertension. The M-ANNHEIM Severity score was used as global marker for disease activity in CP.

RESULTS

Compared to healthy controls, pancreatic SWV was significantly elevated in CP (1.38 vs. 0.96 m/s; p < 0.0001, MWU-test). Pancreatic SWV was increased in alcoholic CP but not in hereditary CP. Receiver operating characteristic analysis revealed 1.2 m/s as the optimal cut-off to identify non-heredity-CP subjects (90% specificity; 81% sensitivity; 92% positive predictive value). Pancreatic SWV correlated significantly with the M-ANNHEIM Severity score, severity of CP-typical complications (both p < 0.05, linear regression analysis), morphological changes of the pancreas and need for hospital treatment (both p < 0.05, MWU-test) but not with exocrine or endocrine insufficiency. Pancreatic SWV >1.7 m/s was identified to predict M-ANNHEIM Severity score ≥11 points. Pancreatic SWV was also elevated in LC (1.42 m/s; p < 0.001), correlating with increased splenic SWV.

CONCLUSION

Transcutaneous pancreatic p-SWE represents a bedside, cost-effective and non-invasive tool which adds valuable information to the process of diagnosing and monitoring CP. By portal hypertension, an increased pancreatic SWV must be expected.

Investigating the role of ultrasound-based shear wave elastography in kidney transplanted patients: correlation between non-invasive fibrosis detection, kidney dysfunction and biopsy results-a systematic review and meta-analysis

INTRODUCTION

Interstitial fibrosis and tubular atrophy are leading causes of renal allograft failure. Shear wave elastography could be a promising noninvasive method for providing information on the state of the kidney, with specific regard to fibrosis but currently available data in the literature are controversial. Our study aimed to analyze the correlation between shear wave elastography and various kidney dysfunction measures.

METHODS

This review was registered on PROSPERO (CRD42021283152). We systematically searched three major databases (MEDLINE, Embase, and CENTRAL) for articles concerning renal transplant recipients, shear wave elastography, fibrosis, and kidney dysfunction. Meta-analytical calculations for pooled Pearson and Spearman correlation coefficients (r) were interpreted with 95% confidence intervals (CIs). Heterogeneity was tested with Cochran's Q test. I2 statistic and 95% CI were reported as a measurement of between-study heterogeneity. Study quality was assessed with the QUADAS2 tool.

RESULTS

In total, 16 studies were included in our meta-analysis. Results showed a moderate correlation between kidney stiffness and interstitial fibrosis and tubular atrophy, graded according to BANFF classification, on biopsy findings for pooled Pearson (r = 0.48; CI: 0.20, 0.69; I2 = 84%) and Spearman correlations (r = 0.57; CI: 0.35, 0.72; I2 = 74%). When compared to kidney dysfunction parameters, we found a moderate correlation between shear wave elastography and resistive index (r = 0.34 CI: 0.13, 0.51; I2 = 67%) and between shear wave elastography and estimated Glomerular Filtration Rate (eGFR) (r = -0.65; CI: - 0.81, - 0.40; I2 = 73%). All our outcomes had marked heterogeneity.

CONCLUSION

Our results showed a moderate correlation between kidney stiffness measured by shear wave elastography and biopsy results. While noninvasive assessment of kidney fibrosis after transplantation is an important clinical goal, there is insufficient evidence to support the use of elastography over the performance of a kidney biopsy.

Point Shear Wave Elastography for Splenic Assessment: A Comparative Study of Splenomegaly and Normal Spleens

Background The spleen, a key immunological organ, plays a crucial role in filtering aged or damaged red blood cells. Splenomegaly, an enlargement of the spleen, can arise from a variety of physiological and pathological conditions, including hematological disorders, hepatic diseases, and infections. Accurate diagnosis and evaluation of splenomegaly are essential for effective treatment. Objectives The objective of this study was to evaluate splenic stiffness in patients with splenomegaly using point shear wave elastography (pSWE) and compare the findings with those of individuals with normal spleen. Materials and methods This hospital-based observational study was conducted at Dr. D. Y. Patil Medical College, Hospital and Research Centre, Pune, India, from October 2022 to December 2023. The study included 56 participants, divided into two groups: 28 patients with splenomegaly and 28 healthy controls. Spleen stiffness was measured using a Samsung HS70A ultrasound machine (Samsung Electronics Pvt. Ltd., Seoul, South Korea), and pSWE was performed with a curvilinear probe. Data were analyzed using IBM SPSS Statistics for Windows, Version 26.0 (Released 2019; IBM Corp., Armonk, New York, United States), and the significance of differences was assessed using an independent t-test with a p-value of <0.05, considered statistically significant. Results The mean spleen stiffness, measured in kilopascals (kPa), was significantly higher in individuals with splenomegaly (32.05 ± 12.54 kPa) compared to controls (22.9 ± 9.49 kPa) (p = 0.003). A positive correlation (rho = 0.482, p < 0.001) was observed between spleen diameter and spleen stiffness. Conclusion This study demonstrates that pSWE is an effective, non-invasive tool for assessing spleen stiffness. The higher spleen stiffness in splenomegaly patients underscores pSWE's diagnostic utility, with a positive correlation between spleen diameter and stiffness. Further multi-center studies are recommended to validate these findings, highlighting pSWE's promise in evaluating and monitoring splenic disorders.

Our experience with liver and spleen elastography in the prediction of oesophageal varices

Background

Variceal bleeding is an important cause of mortality in patients with chronic liver disease (CLD). The gold standard for detection and grading of oesophageal varices (EV) is upper gastrointestinal endoscopy. However, it is expensive, time-consuming and invasive.

Objectives

This study aimed to find any association between splenic shear wave velocity (SWV) measured by acoustic radiation force imaging (ARFI) and the presence of EV.

Method

The quasi-experimental study included 50 patients with CLD and 50 subjects without CLD as the control group. Both underwent upper abdominal ultrasonography followed by elastographic assessment on a Siemens Acuson S2000TM ultrasound system. A comparison of the findings was made between the control and patient groups.

Results

Both groups had similar hepatic size while patients with CLD had larger splenic size and area (p < 0.05). The CLD patients had higher mean hepatic and splenic SWV compared with the control group (p < 0.05). The mean splenic size and splenic SWV were higher in patients with varices than in those without varices (p < 0.05).

Conclusion

Chronic liver disease causes significant increase in liver and splenic stiffness with splenic SWV values being higher for patients with varices emphasising the role of elastography as a non-invasive predictor for the presence of EVs. Splenic SWV had the highest sensitivity and specificity, which was augmented by a combination of hepatic and splenic SWV. Thus, splenic SWV alone or in combination with hepatic SWV is a useful technique for prediction of the presence of EVs.

Contribution

This study aims to find an alternative non-invasive and cost-effective technique for screening of EV.

High correlation of hepatic shear wave velocity with esophageal varices complication rate in patients with chronic liver diseases

BACKGROUND

Histological evaluation by liver biopsy is considered the gold standard for assessing liver disease; however, it is highly invasive. Non-invasive liver stiffness measurement by shear wave elastography (SWE) is effective for evaluating the hepatic fibrosis stage and related diseases. In this study, we investigated the correlations of liver stiffness with hepatic inflammation/fibrosis, functional hepatic reserve, and related diseases in patients with chronic liver disease (CLD).

METHODS

Shear wave velocity (Vs) values were measured using point SWE in 71 patients with liver disease from 2017 to 2019. Liver biopsy specimens and serum biomarkers were collected at the same time, and splenic volume was measured using computed tomography images with the software Ziostation2. Esophageal varices (EV) were evaluated by upper gastrointestinal endoscopy.

RESULTS

Among CLD-related function and complications, Vs values were highly correlated with liver fibrosis and EV complication rates. The median Vs values for liver fibrosis grades F0, F1, F2, F3, and F4 were 1.18, 1.34, 1.39, 1.80, and 2.12 m/s, respectively. Comparison of receiver operating characteristic (ROC) curves to predict cirrhosis showed that area under the ROC (AUROC) curve for Vs values was 0.902, which was not significantly different from the AUROCs for the FIB-4 index, platelet count, hyaluronic acid, or type IV collagen 7S, while it was significantly different from the AUROC for mac-2 binding protein glycosylation isomer (M2BPGi) (P < 0.01). Comparison of ROC curves to predict EV showed that the AUROC for Vs values was 0.901, which was significantly higher than the AUROCs for FIB-4 index (P < 0.05), platelet count (P < 0.05), M2BPGi (P < 0.01), hyaluronic acid (P < 0.05), and splenic volume (P < 0.05). In patients with advanced liver fibrosis (F3 + F4), there was no difference in blood markers and splenic volume, while Vs value was significantly higher in patients with EV (P < 0.01).

CONCLUSIONS

Hepatic shear wave velocity was highly correlated with EV complication rates in chronic liver diseases as compared to blood markers and splenic volume. In advanced CLD patients, Vs values of SWE are suggested to be effective in predicting the appearance of EV noninvasively.

Liver stiffness-spleen diameter to platelet ratio score (LSPS model) predicts variceal rebleeding for cirrhotic patients

PURPOSE

The liver stiffness- spleen diameter to platelet ratio score (LSPS model) can identify a high risk of decompensated events in cirrhotic patients. We aimed to evaluate the value of the LSPS model as a risk stratification strategy in the secondary prevention for cirrhotic patients with esophageal and gastric variceal bleeding (EGVB).

METHODS

Consecutive EGVB patients who underwent liver stiffness measurement by acoustic radiation force impulse, platelet count and ultrasonography were enrolled between January 2013 and December 2019. We calculated the LSPS of all patients and followed up for over 2 years. The primary outcome was rebleeding. Transplant-free survival and overt hepatic encephalopathy (OHE) were the secondary outcomes.

RESULTS

A total of 131 patients were analyzed. The median value of the LSPS model is 0.1879. We developed risk stratification based on the LSPS model and divided the patients into two groups: the high-LSPS (LSPS > 0.1879) group and the low-LSPS (LSPS ≤ 0.1879) group. Sixty-two (47.33%) patients suffered rebleeding, in which there were 21 (31.92%) patients with low LSPS and 41 (63.08%) patients with high LSPS (hazard ratio 2.883; 95% confidence interval, 1.723-4.822, P  < 0.001). For the whole cohort, the rates of transplant-free survival and OHE were consistently similar between the two groups at 2 years.

CONCLUSION

The LSPS is a reliable, noninvasive method for the detection of a high risk of rebleeding for the secondary prevention of EGVB.

Diagnostic accuracy of magnetic resonance elastography and point-shear wave elastography for significant hepatic fibrosis screening: Systematic review and meta-analysis

The hepatic diseases are extremely common in clinical practice. The correct classification of liver fibrosis is extremely important, as it influences therapy and predicts disease outcomes. The purpose of this study is to compare the diagnostic performance of point-shear wave elastography (pSWE) and magnetic resonance elastography (MRE) in the hepatic fibrosis diagnostic. A meta-analysis was carried out based on articles published until October 2020. The articles are available at following databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Scientific Electronic Library Online, LILACS, Scopus, and CINAHL. Diagnostic performances were analyzed per METAVIR F2, using 3.5kPa as target fibrosis. Assessment of the methodological quality of the incorporated papers by the QUADAS-2 tool for pSWE and MRE. A total 2,153 studies articles were evaluated and 44 studies, comprising 6,081 patients with individual data, were included in the meta-analysis: 28 studies for pSWE and 16 studies for MRE. The pooled sensitivity and specificity were 0.86 (95%CI 0.80-0.90) and 0.88 (95%CI 0.85-0.91), respectively, for pSWE, compared with 0.94 (95%CI 0.89-0.97) and 0.95 (95%CI 0.89-0.98) respectively, for MRE. The pooled SROC curve for pSWE shows in the area under the curve (AUC) of 0.93 (95%CI 0.90-0.95), whereas the AUC for MRE was 0.98 (95%CI 0.96-0.99). The diagnostic odds ratio for pSWE and MRE were 41 (95%CI 24-72) and 293 (95%CI 86-1000), respectively. There was statistically significant heterogeneity for pSWE sensitivity (I² = 85.26, P<0.001) and specificity (I² = 89.46, P<0.001). The heterogeneity for MRE also was significant for sensitivity (I² = 73.28, P<0.001) and specificity (I² = 87.24, P<0.001). Therefore, both pSWE and MRE are suitable modalities for assessing liver fibrosis. In addition, MRE is a more accurate imaging technique than pSWE and can be used as alternative to invasive biopsy.

Liver and spleen stiffness for the diagnosis of oesophageal varices in adults with chronic liver disease

This is a protocol for a Cochrane Review (diagnostic). The objectives are as follows:

To assess the diagnostic accuracy of liver stiffness and spleen stiffness, separately or in combination, as measured by vibration‐controlled transient elastography (VCTE) in detection of any oesophageal varices in adults with chronic liver disease. We will regard a combination of tests as positive when at least one is positive.

To compare the diagnostic accuracy of individual tests (liver stiffness and spleen stiffness measured by VCTE) directly and versus the combination of both tests (considering positive when at least one is positive) in detecting any oesophageal varices.

To assess the diagnostic accuracy of liver stiffness and spleen stiffness, separately or in combination, as measured by other elastography techniques (2D‐shear wave elastography (2D‐SWE), point shear wave elastography (pSWE), magnetic resonance elastography (MRE)) in detection of any oesophageal varices in adults with chronic liver disease. We will regard a combination of tests as positive when at least one is positive.

To compare the diagnostic accuracy of liver stiffness and spleen stiffness measured by VCTE with other techniques (pSWE, 2D‐SWE, MRE) in detection of any oesophageal varices in adults with chronic liver disease.

Assessment of variceal bleeding in cirrhotic patients: accuracy of multi-detector computed tomography

Background

Esophageal variceal hemorrhage (EVH) has been shown to be a leading cause of mortality in patients with portal hypertension. Our purpose was to assess the utility of multi-detector computed tomography (MDCT) features in the assessment of esophageal varices (EVs) and esophageal variceal hemorrhage (EVH). This prospective study included 85 cirrhotic patients who underwent MDCT and Upper Gastrointestinal Tract (UGIT) endoscopy within 2 weeks. Four radiologists evaluated the presence of EVs and the presence and size of different collaterals. Multivariable logistic regression analysis was calculated to investigate the significant predictors influencing EV and EVH.

Results

Findings of EV with MDCT were the best predictor of EV or EVH. The presence (and/or size) of following collaterals had significant association with both EV and EVH: paraesophageal (p < 0.001, < 0.001), short gastric (p = 0.024, 0.010), gastric varicosities (p < 0.001, < 0.001), coronary (p < 0.001, < 0.001), and main coronary vein (MCV) (p < 0.001, = 0.011). We proposed an imaging-based model (presence of coronary collaterals, main coronary vein size > 3.5 mm, presence of short gastric collaterals, presence of gastric varicosities, size > 1.5 mm) with 97% sensitivity, 91% specificity, and 94% accuracy to predict EVs. We suggested another model (presence of paraesophageal collaterals, presence of short gastric vein (SGC), SGC size > 2.5 mm, main coronary vein size > 3.5 mm, gastric varicosities size > 1.5 mm, size of EVs > 4 mm, and Child C score) to predict EVH with 98% sensitivity, 81% specificity, and 89.5% accuracy. Inter-observer agreement was high in the detection of EVs (W. Kappa = 0.71–0.88).

Conclusion

MDCT is an effective modality in the diagnosis of EVs. At MDCT, the presence and/or size of various collaterals including para-esophageal, short gastric, coronary collaterals, and gastric varicosities are accurate predictors for either EVs existence or EVH. We suggested two computed tomography imaging-based models with high reproducibility and acceptable accuracy for the prediction of EV and EVH. With cirrhotic patients, we recommend that radiologists report collaterals in their daily practice.

Diagnostic Performance of Acoustic Radiation Force Impulse Imaging in Evaluating Liver Fibrosis in Patients with Chronic Hepatitis B Infection: A Cross-Sectional Study

Background  Acoustic radiation force impulse point shear wave elastography (ARFI-pSWE), measuring shear-wave velocity (SWV), has been utilized to examine the liver stiffness caused by different etiologies. However, information on its reliability in staging liver fibrosis in chronic hepatitis B (CHB) patients is scarce.

Purpose  The aim of the study is to examine the diagnostic performance of ARFI-pSWE and determine the optimal SWV cut-off values to predict significant fibrosis ( F ≥2) and cirrhosis (F4) in CHB patients.

Material and Methods  All 114 adult CHB patients visiting the University Medical Center, Ho Chi Minh City, Vietnam between February 2019 and March 2021 underwent liver stiffness measurement using ARFI-pSWE and FibroScan. SWV results were tested against FibroScan for sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The area under the receiver operating characteristic (AUROC) curve was used to identify the optimal SWV cut-off values.

Results  There was a strong agreement between ARFI-pSWE and FibroScan ( r  = 0.92, p <0.001). The optimal SWV cut-off value for detecting significant fibrosis was 1.37 m/s with an AUROC of 0.975, sensitivity of 83.3%, specificity of 100%, PPV of 100%, and NPV of 81%. The optimal cut-off value for predicting cirrhosis was 1.70 m/s with an AUROC of 0.986, sensitivity of 97%, specificity of 93%, PPV of 95%, and NPV of 96%.

Conclusion  ARFI-pSWE could be an effective technique for evaluating liver fibrosis in CHB patients. SWV cut-off values of 1.37 and 1.70 m/s could be used to diagnose significant fibrosis and cirrhosis, respectively.

Prediction of high-risk esophageal varices in patients with chronic liver disease with point and 2D shear wave elastography: a systematic review and meta-analysis

OBJECTIVE

To assess the diagnostic performance of liver stiffness (LS) and spleen stiffness (SS) measured by point shear wave elastography (pSWE) and 2D shear wave elastography (2D-SWE) in the detection of high-risk esophageal varices (HREV) and to compare their diagnostic accuracy.

METHODS

Through systematic search of PubMed, Embase, and Web of Science databases, we included 17 articles reporting the diagnostic performance of LS or SS measured by pSWE or 2D-SWE for HREV. We used a bivariate random-effects model to estimate pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), area under summary receiver operator characteristic curve (AUSROC), and diagnostic odds ratio (DOR).

RESULTS

For LS, there was no significant difference between the pooled sensitivity, 0.89 (95% confidence interval CI, 0.81-0.94) vs. 0.8 (95% CI, 0.72-0.86) (p = 0.13), and specificity, 0.81 (95% CI, 0.73-0.87) vs. 0.73 (95% CI, 0.65-0.79) (p = 0.07) of pSWE and 2D-SWE. The AUSROC and DOR of pSWE were higher than those of 2D-SWE: 0.92 (95% CI, 0.89-0.94) vs. 0.84 (95% CI, 0.80-0.87), p = 0.03, 33 (95% CI, 25-61) vs. 11 (95% CI, 5-22), (p < 0.01). For SS, there was no significant difference between the pooled sensitivity 0.91 (95% CI, 0.78-0.96) vs. 0.89 (95% CI, 0.80-0.94) (p = 0.43); specificity, 0.79 (95% CI, 0.72-0.84) vs. 0.72 (95% CI, 0.63-0.79) (p = 0.06); and DOR, 35 (95% CI, 13-100) vs. 20 (95% CI, 8-50) (p = 0.16) of pSWE and 2D-SWE.

CONCLUSION

LS and SS measured by pSWE and 2D-SWE have good accuracy in predicting HREV.

KEY POINTS

• There is modest difference between the diagnostic performance of LS and SS measured by pSWE and 2D-SWE. • LS and SS measured by pSWE and 2D-SWE both have high sensitivity, specificity, and AUSROC for the evaluation of HREV in patients with CLD. • pSWE and 2D-SWE are promising tools for noninvasive monitoring risk of esophageal varices bleeding of CLD patients.

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.

Spleen elastography in patients with Systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune inflammatory connective tissue disease. It is characterized by varying degrees of fibrosis of the skin and internal organs. Tissue fibrosis is the final phase of a complex biological process of immune activation and vascular damage. The spleen is one of the organs thought to be involved in a systemic fibrosing process. Yet, there is a lack of research that provides evidence about splenic involvement in patients with SSc through objective instrumental techniques. Ultrasound elastography is a modern method which detects changes in the stiffness and elasticity of different organs. To assess the elasticity and stiffness of the spleen in healthy subjects and patients with SSc, the study included 34 patients with SSc and 35 healthy volunteers. Point SWE spleen elastography was performed on all participants in the two study groups through an Esaote MyLab 9 eXP with a C1-8 iQ appleprobe transducer. The mean age in the SSc patient group was 47.35 ± 11.48 years vs. 46.20 ± 14.55 years in the healthy controls, with no significant age difference, p = 0.717. The mean Body Mass Index (BMI) in the SSc patient group was 22.42 ± 2.12 kg/m² vs. 24.23 ± 4.29 kg/m² in the healthy control group with no significant difference, p = 0.410. Among the SSc patients, 18(53%) were with dcSSc and 16 (47%) with lcSSc. The mean disease duration was 59 ± 28 months, ranging between 18 and 118 months. Spleen stiffness median was significantly higher in the SSc patient group (3.19 m/s) in comparison with the healthy controls (2.40 m/s), p < 0.001. Spleen size was normally distributed and did not differ significantly between the SSc patients (105.84 ± 7.87 mm) and the healthy controls (104.16 ± 8.99 mm), p = 0.410. A significantly higher mean of spleen stiffness was observed in the dcSSc patients (3.38 ± 0.20 m/s) in comparison with the lcSSc group (2.81 ± 0.38 m/s), p < 0.001. Spleen size did not show a significant association with the type of SSc. Spleen size in the dcSSc subgroup had a mean value of 103.45 ± 5.56 mm vs. 108.51 ± 9.30 in the lcSSc subgroup, p = 0.071. pSWE is an objective, reliable, and easy-to-implement method for detecting early fibrous changes in the spleen in patients with SSc. A good approach in patients with SSc could be the search for similar processes in other internal organs, such as the liver and thyroid gland.

Liver and spleen elastography of dogs affected by brachycephalic obstructive airway syndrome and its correlation with clinical biomarkers

The purpose of this study is to determine whether the brachycephalic obstructive airway syndrome (BOAS) is correlated to alterations in liver and spleen elasticity. Forty-eight brachycephalic and 22 mesocephalic dogs were submitted to a BOAS functional assessment, laboratory tests, abdominal ultrasound and liver and spleen Acoustic Radiation Force Impulse (ARFI) elastography. Dogs clinically affected by BOAS had higher values of liver stiffness (p < 0.001) than healthy dogs: medial lobes (1.57 ± 0.37 m/s), left and right lateral lobes (1.54 ± 0.50 m/s, 1.23 ± 0.28 m/s, respectively) and caudate lobe (1.28 ± 0.42 m/s). Compared to the mesocephalic group, the brachycephalic group (BOAS clinically affected and unaffected dogs) had higher spleen (2.51 ± 0.45 m/s; p < 0.001) and liver stiffness (p < 0.001): medial lobes (1.53 ± 0.37 m/s), left and right lateral lobes (1.47 ± 0.47 m/s, 1.20 ± 0.30 m/s, respectively) and caudate lobe (1.23 ± 0.40 m/s). Principal component analysis explained 70% of the variances composed by liver stiffness increase, erythrocytes and alanine aminotransferase reduction. Brachycephalic dogs had higher spleen and liver stiffness and a subacute inflammatory state, which represent another BOAS systemic effect. Consequently, these dogs can be at higher risk of hepatic disorders compared with mesocephalic dogs, similarly to humans affected by sleep apnea syndrome.

Diagnostic accuracy of spleen stiffness to evaluate portal hypertension and esophageal varices in chronic liver disease: a systematic review and meta-analysis

Objectives

To systematically review studies on the diagnostic accuracy of spleen stiffness measurement (SSM) for the detection of clinical significant portal hypertension (CSPH), severe portal hypertension (SPH), esophageal varices (EV), and high-risk esophageal varices (HREV) in patients with chronic liver diseases (CLD).

Methods

Through a systematic search, we identified 32 studies reporting the accuracy of SSM for the diagnosis of portal hypertension (PH) and/or EV in adults with CLD. A bivariate random-effects model was performed to estimate pooled sensitivity, specificity, likelihood ratio, positive predictive value (PPV), negative predictive value (NPV), and diagnostic odds ratios (DOR). The clinical utility of SSM was evaluated by Fagan plot.

Results

A total of 32 studies assessing 3952 patients were included in this meta-analysis. The pooled sensitivities of SSM were 0.85 (95% confidence interval (CI), 0.69–0.93) for CSPH; 0.84 (95% CI, 0.75–0.90) for SPH; 0.90 (95% CI, 0.83–0.94) for any EV; and 0.87 (95% CI, 0.77–0.93) for HREV. The pooled specificities of SSM were 0.86 (95% CI, 0.74–0.93) for CSPH; 0.84 (95% CI, 0.72–0.91) for SPH; 0.73 (95% CI, 0.66–0.79) for EV; and 0.66 (95% CI, 0.53–0.77) for HREV. Summary PPV and NPV of SSM for detecting HREV were 0.54 (95% CI, 0.47–0.62) and 0.88 (95% CI, 0.81–0.95), respectively.

Conclusions

Our meta-analysis suggests that SSM could be used as a helpful surveillance tool in management of CLD patients and was quite useful for ruling out the presence of HREV thereby avoiding unnecessary endoscopy.

Key Points

• SSM could be used to rule out the presence of HREV in patients with CLD thereby avoiding unnecessary endoscopy.

• SSM has significant diagnostic value for CSPH and SPH with high sensitivity and specificity in patients with CLD.

• SSM could be used as a helpful surveillance tool for clinicians managing CLD patients.

Electronic supplementary material

The online version of this article (10.1007/s00330-020-07223-8) contains supplementary material, which is available to authorized users.

Esophageal variceal hemorrhage: the role of MDCT characteristics in predicting the presence of varices and bleeding risk

PURPOSE

To investigate the associated Multi-Detector Computed Tomography (MDCT) features for esophageal varices (EVs) and esophageal variceal hemorrhage (EVH), with particular emphasis on different collateral veins.

MATERIALS AND METHODS

All cirrhotic patients who had undergone both Upper Gastrointestinal Tract (UGIT) endoscopy and contrast-enhanced MDCT within 6 months from 2013 to 2019 were included in the study. MDCT of 124 patients, 76 males and 48 females, aged between 21 and 73 years old were evaluated for presence of EV and presence and size of different collaterals. The presence and size of collaterals in patients with high-risk EVs or EVH were compared with others.

RESULTS

Findings of EV in MDCT analysis were the best predictor of EV or EVH, and presence (and/or size) of following collaterals showed a significant relationship with both EV and EVH: coronary (p = 0.006, 0.002), short gastric (SGC) (p = 0.02, < 0.001), and paraesophageal (p = 0.04, 0.01). Those presenting each aforementioned collaterals or with higher collateral size were more likely to develop the EV or EVH. Yet, other collaterals indicated no similar association: para-umbilical, omental, perisplenic, and splenorenal. Main coronary vein (p = 0.02, 0.03) and fundus (p = 0.006, 0.001) varices' sizes were also significantly higher in patients with EV or EVH. Finally, we suggested an imaging-based model (presence of SGC, SGC size > 2.5 mm, presence of EV, and coronary vein size > 3.5 mm) with 75.86% sensitivity, 76.92% specificity, and 76.36% accuracy to predict the presence of EVs according to UGIT endoscopy. Furthermore, we presented another model (presence of SGC, SGC size > 2.5 mm, presence of EV, and MELD score > 11.5 mm) to predict the occurrence of EVH with 75.86% sensitivity, 76.92% specificity, and 76.36% accuracy.

CONCLUSION

We suggested imaging characteristics for predicting EV and EVH with especial emphasis on the presence and size of various collaterals; then, we recommended reliable imaging criteria with high specificity and accuracy for predicting the EV and EVH.

The role of spleen stiffness using ARFI in predicting esophageal varices in patients with Hepatitis B and C virus-related cirrhosis

INTRODUCTION

Current guidelines recommend that all patients with cirrhosis undergo upper gastrointestinal endoscopy (UGE) screening for esophageal varices (EV). Unfortunately, UGE has a lot of disadvantages, consequently various non-invasive methods of diagnosing EV have been proposed. We evaluated if spleen stiffness (SS) measured by Acoustic Radiation Force Impulse (ARFI) is a viable technique in diagnosing EV.

METHODS

We recruited 178 patients with cirrhosis caused by Hepatitis B and C who underwent biochemical tests, abdominal ultrasound, UGE, LS and SS measurements using ARFI elastography. Based on the endoscopic results the patients were divided in 3 groups: without EV, with small EV (<5 mm) and with large EV (>5 mm).

RESULTS

ARFI SS was the only non-invasive parameter associated with the presence of EV (2.7±0.30 vs. 3.4±0.52, p<0.001) and large EV (2.91±0.36 vs. 3.86±0.37, p=0.001) after multivariate logistic regression (p<0.001). ARFI SS for predicting EV showed an AUROC of 0.872 (CI 95%: 0.799-0.944), for a cut-off value of 2.89 m/s: Sensitivity (Se) 91.4% (CI 95%: 81-97%), Specificity (Sp) 67.7% (CI 95%: 51-85%). ARFI SS for diagnosing large EV (>5mm) had better results with an AUROC 0.969 (CI 95%:0.935-0.99), and for a cut-off of 3.30 m/s: Se 96.4% (CI 95%: 82-99.9%), Sp 88.5% (CI 95%: 78-95%).

CONCLUSIONS

SS measured using ARFI is a good method of detecting EV and is an excellent method of diagnosing large EV in patients with virus-related cirrhosis.

Acoustic radiation forced impulse-based splenic prediction model using data mining for the noninvasive prediction of esophageal varices in hepatitis C virus advanced fibrosis

BACKGROUND

Esophageal varices (EV) are serious complications of hepatitis C virus (HCV) cirrhosis. Endoscopic screening is expensive, invasive, and uncomfortable. Accordingly, noninvasive methods are mandatory to avoid unnecessary endoscopy. Acoustic radiation forced impulse (ARFI) imaging using point shear wave elastography as demonstrated with virtual touch quantification is a possible noninvasive EV predictor. We aimed to validate the reliability of liver stiffness (LS) and spleen stiffness (SS) by an ARFI-based study together with other noninvasive parameters for EV prediction in HCV patients. Also, we aimed to evaluate the diagnostic performance of a new simple prediction model (incorporating SS) using data mining analysis.

PATIENTS AND METHODS

This cross-sectional study included 200 HCV patients with advanced fibrosis. Labs, endoscopic, ultrasonographic, LS, and SS data were collected. Their accuracy in diagnosing EV was assessed and a data mining analysis was carried out.

RESULTS

Ninety patients (22/46% of F3/F4 patients) had EV (39/30/18/3 patients had grade I/II/III/IV, respectively). LS and SS by ARFI showed high significance in differentiating not only patients with/without EV (P = 0.000 for both) but also correlated with the grading of varices (R = 0.31 and 0.45, respectively; P = 0.000 for both). Spleen longitudinal diameter (SD), splenic vein diameter (SVD), platelets to spleen diameter ratio, LOK index, and FIB-4 score were the best ultrasonographic and biochemical predictors for the prediction of EV [area under receiver operating characteristic (AUROC) 0.79, 0.76, 0.76, 0.74, and 0.71, respectively]. SS (using ARFI) had better diagnostic performance than LS for the prediction of EV (AUROC = 0.76 and 0.70, respectively). The diagnostic performance increased using data mining to construct a simple prediction model: high probability for EV if [(SD cm) × 0.17 + (SVD mm) × 0.06 + (SS) × 0.97] more than 6.35 with AUROC 0.85.

CONCLUSION

SS by ARFI represents a reliable noninvasive tool for the prediction of EV in HCV patients, especially when incorporated into a new data mining-based prediction model.

Spleen Stiffness as Predictor of Esophageal Varices in Cirrhosis of Different Etiologies

The purpose of this study is to determine whether esophageal varices (EV) can be identified through the evaluation of spleen stiffness (SSM) via acoustic radiation force impulse (ARFI). A total of 135 patients suffering from cirrhosis underwent a clinical exam, laboratory tests, abdominal ultrasound, liver stiffness (LSM) measurement, SSM evaluation and upper gastrointestinal endoscopy. Based on the endoscopy results, the patients were classified into three groups: those with no evident EV, those with small EV and those with varices needing treatment (VNT). Patients with EV of any grade had significantly higher average SSM values over those with no EV (3.37 m/s versus 2.79 m/s, p-value < 0.001), while patients with VNT showed an even greater difference (3.96 m/s versus 2.93 m/s, p-value < 0.001). SSM proved to be an excellent method of predicting patients with VNT.

Liver Stiffness Detected by Shear Wave Elastography Predicts Esophageal Varices in Cirrhotic Patients

ABSTRACT

Ultrasound elastography has become a promising noninvasive approach for assessing liver fibrosis. The purpose of this study was to evaluate the diagnosis ability of liver stiffness detected by shear wave elastography (SWE) for predicting the presence of esophageal varices (EVs) in cirrhotic patients. Four hundred sixty-eight cirrhotic patients were enrolled consecutively. Liver stiffness and EVs were detected by SWE and endoscopy, respectively. The baseline characteristics were recorded, and areas under the receiver operating characteristic curves (AUROCs) were used to compare the diagnosis accuracy. Multivariate analysis was used to identify the risk factors for EVs in cirrhosis. The mean liver stiffness was 18.4 kPa with a range of 6.8 to 52.5 kPa. Two hundred seventy-one patients had no EVs (57.9%), 139 patients had F1 EVs (29.7%), and 58 patients had high-risk EVs (12.4%). The optimal cutoff values of SWE for predicting EVs and high-risk varices were 18.5 and 20.4 kPa, respectively. The AUROCs for predicting the incidence of EVs were 0.792 (95% confidence interval [CI], 0.884-0.842), 0.814 (95% CI, 0.658-0.875), and 0.895 (95% CI, 0.813-0.918) for platelet, platelet count-to-spleen diameter ratio, and liver stiffness, respectively. For predicting the presence of high-risk varices, liver stiffness again had the highest AUROC. Multivariate analysis identified liver stiffness and platelet count-to-spleen diameter ratio as independent predictive factors for EVs in cirrhosis. Liver stiffness measured by SWE is an effective diagnostic tool for predicting EVs with greater accuracy, and SWE value is an independent factor for predicting high-risk EVs.

Rational arrangement of measuring shear wave speed in the liver

BACKGROUND

Shear wave speed has been widely applied to quantify a degree of liver fibrosis. However, there is no standardized procedure, which makes it difficult to utilize the speed universally.

AIM

To provide procedural standardization of shear wave speed measurement.

METHODS

Point shear wave elastography (pSWE) was measured in 781 patients, and two-dimensional shear wave elastography (2dSWE) was measured on the same day in 18 cases. Regions-of-interest were placed at 12 sites, and the median and robust coefficient-of-variation (CVR) were calculated. A residual sum-of-square (Σdi 2) was computed for bootstrap values of 1000 iterations in 18 cases with each assumption of 1 to 12 measurements. The proportion of the Σdi 2 (%Σdi 2) was calculated as the ratio of Σdi 2 to pSWE after converting it based on the correlation between pSWE and 2dSWE.

RESULTS

The CVR showed a significantly broader distribution in the left lobe (P < 0.0001), and the smallest CVR in the right anterior segment that covered 95% cases was 40.4%. pSWE was significantly higher in the left lobe than in the right lobe (1.63 ± 0.78 m/s vs 1.61 ± 0.78 m/s, P = 0.0004), and the difference between the lobes became further discrete when the subjects were limited to the cases with a CVR less than 40.4% in any segment (1.76 ± 0.80 m/s vs 1.70 ± 0.82 m/s, P < 0.0001). The highest values of the CVR in every 0.1 m/s interval were plotted in convex upward along pSWE and peaked at 1.93 m/s. pSWE and 2dSWE were significantly correlated (P < 0.0001, r = 0.95). In 216000 resamples from 18 cases, the %Σdi 2 of 12 sites was 8.0% and gradually increased as the acquisition sites decreased to reach a significant difference with a %Σdi 2 of 7 sites (P = 0.027).

CONCLUSION

These data suggest that shear wave speed should be measured at 8 or more sites of spreading in both lobes.

The relationship of spleen stiffness value measured by shear wave elastography with age, gender, and spleen size in healthy volunteers

PURPOSE

The aim of this study is to evaluate spleen stiffness values with shear wave elastography (SWE) quantitatively in healthy adults and investigate the relationship of spleen stiffness with age, gender, and spleen size.

METHODS

This study included 65 healthy individuals. Spleen stiffness measurement was obtained with 2 dimensional (2-D) SWE method from the middle portion of spleen and calculated in kilopascals by taking the average of three valid measurements. Longitudinal and transverse spleen sizes were measured. The relationship of spleen stiffness with age, gender, and spleen size was investigated. The association between spleen size and age and gender was also evaluated.

RESULTS

The mean spleen stiffness value was 13.82 ± 2.91 kPa, and the spleen stiffness was not affected by age, gender, or spleen size. Longitudinal spleen size was significantly lower in females than that in males. Moreover, there was a significant negative correlation between longitudinal spleen size and age (r = 0.247, p = 0.048).

CONCLUSION

Spleen stiffness can be quantitatively measured by 2-D SWE, and the spleen stiffness is not affected by age, gender, and spleen size. The values obtained in this study can be used as normal base values in examination of different spleen pathologies.

Accuracy of liver stiffness, spleen stiffness, and LS-spleen diameter to platelet ratio score in detection of esophageal varices: Systemic review and meta-analysis

BACKGROUND AND AIM

There is increasing evidence of non-invasive measurement using elastography such liver stiffness (LS), spleen stiffness (SS), and LS-spleen diameter to platelet ratio score (LSPS) for detection of esophageal varices (EV); however, data regarding comparison between these three parameters are limited.

METHODS

We performed a systemic review and meta-analysis of studies evaluating performance of LS, SS, and LSPS for detection of EV and high risk/clinically significant EV (HREV). Pooled sensitivity, specificity, log diagnostic odd ratio (LDOR), and area under the receiver operating characteristic curve (AUC) of LS, SS, and LSPS for detection of EV and HREV were analyzed and compared. Publication bias was assessed by Deeks' funnel plot.

RESULTS

SS and LSPS were superior to LS for detection of EV with higher sensitivity (0.90 and 0.91 vs 0.85), specificity (0.73 and 0.76 vs 0.64), LDOR (3.24 and 3.35 vs 2.26), and AUC (0.899 and 0.851 vs 0.817). For HREV, SS had the highest sensitivity (0.87) followed by LS (0.85) and LSPS (0.82); however, SS had the lowest specificity (0.52), LDOR (2.09), and AUC (0.807) whereas LSPS had the highest specificity (0.77), LDOR (2.74), and AUC (0.861).

CONCLUSION

For detection of EV, we prefer using LSPS and SS over LS when available, while LS, SS, and LSPS cannot be recommended for detection of HREV due to their moderate sensitivity and specificity.

Can acoustic radiation force imaging of the liver and spleen predict the presence of gastroesophageal varices?

AIM

To determine whether acoustic radiation force imaging (ARFI) of the liver/spleen could be used in patients with cirrhosis to predict the presence of gastroesophageal varices (GOVs).

MATERIALS AND METHODS

Fifty-eight patients with cirrhosis who were undergoing 6-monthly ultrasound examinations for hepatoma surveillance and who were due to have oesophagogastroduodenoscopy (OGD) within 6 months of their ultrasound were recruited. During routine ultrasound, the patient's liver and spleen were also assessed using ARFI. Other clinical parameters (platelet count, spleen size, and transient elastography measurements) were also collected. Logistic regression was used to determine which variables were significantly associated with presence or absence of varices univariably and multivariably RESULTS: Fourteen patients (24%) had GOVs. Patients with GOVs had higher ARFI measurements in the liver and spleen than patients without GOVs (liver: 2.39 versus 2.13, spleen: 2.89 versus 2.82), but these results were not statistically significant (odds ratio=1.75, 95% confidence interval [CI]=0.82, 3.91 and odds ratio=1.12, 95% CI=0.33, 3.97, respectively). The platelet/splenic ratio, in comparison, was associated with the presence or absence of GOVs in multivariate analysis (odds ratio=0.32, 95% CI=0.008, 0.91).

CONCLUSION

Although patients with GOVs had overall higher ARFI liver and spleen results, this was not statistically significant. As such, ARFI cannot yet replace OGD in predicting GOVs in this patient group.

Measurement of splenic stiffness by 2D-shear wave elastography in patients with extrahepatic portal vein obstruction

OBJECTIVE:

To assess the accuracy of splenic stiffness (SS) measured by 2D-shear wave elastography (SWE) for predicting variceal bleeding in the patients with extrahepatic portal vein obstruction (EHPVO).

METHODS:

52 patients with EHPVO (mean age: 22.29 years; 26 each males and females) were included in the study after obtaining approval from the institute ethics committee. All patients initially underwent upper gastrointestinal endoscopy followed by ultrasonography, including 2D-SWE on the Aixplorer Supersonic Imagine scanner. The SS was measured through the anterior abdominal wall and an average of three measurements was taken. The SS was then compared with clinical symptoms, variceal grade, and other ultrasonography (USG) parameters. USG parameters were also compared with variceal grade.

RESULTS:

The mean SS was 44.92 ± 12.35 kPa. There was no significant difference in the mean SS of patients with high grade varices (44.30 kPa; n = 25) from those with low grade varices (46.91 kPa; n = 20). The ROC analysis showed a poor area under the curve of 0.477 for the prediction of high grade varices by the SS. The SS did not show any significant correlation with other ultrasonography parameters except splenic size, with which there was a weak but significant correlation. The measurement of SS by 2D-SWE was reliable and Cronbach's alpha was 0.905.

CONCLUSION:

The SS measured by 2D-SWE is not an accurate predictor of variceal grade and thus bleeding in patients of EHPVO.

ADVANCES IN KNOWLEDGE:

EHPVO is a vascular pathology with most patients showing splenomegaly and preserved liver function. Although, elastography of spleen has been shown to be useful in patients with cirrhosis for predicting portal hypertension, it does not seem to be helpful in patients with EHPVO.

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.

Point Shear Wave Elastography of the Spleen: Its Role in Patients with Portal Hypertension

The goals of the study described here were to evaluate the feasibility and reproducibility of measuring spleen stiffness (SS) using point shear wave elastography in a series of cirrhotic patients and to investigate whether SS, liver stiffness (LS) and other non-invasive parameters are correlated with the presence of esophagogastric varices (EVs). Fifty-four cirrhotic patients with low-grade EVs or without EVs at esophago-gastro-duodenoscopy were enrolled. They underwent abdominal ultrasound and Doppler ultrasound of hepatic vessels simultaneously with p-SWE of the liver and spleen. In 42 patients, the accuracy of LS and SS, as well as of platelet count and spleen longitudinal diameter, in predicting the presence of EVs was evaluated. The technical success was 90.74% for LS (49/54 patients) and 77.78% for SS (42/54 patients). Inter-observer agreement for SS measurement was high. Both LS and SS correlated with esophago-gastro-duodenoscopy: LS had the highest accuracy in predicting the presence of EVs (area under the receiver operating characteristic curve [AUROC] = 0.913); SS had the lowest accuracy (AUROC = 0.675); platelet count and spleen diameter had intermediate accuracy (AUROC = 0.731 and 0.729, respectively). SS did not have an advantage over LS in predicting low-grade EVs and cannot be proposed as a useful tool in the diagnostic process of cirrhotic patients who require screening esophago-gastro-duodenoscopy.

Clinical applications of spleen ultrasound elastography - a review

In the last few years, notable technical progress has taken place in ultrasound elastography. Qualitative methods have been replaced by quantitative ones, such as: transient elastography, acoustic radiation force impulse and shear wave elastography. Owing to the fact that the spleen is superficially located, it is possible to obtain reliable measuring accuracy of its hardness using sonoelastography. Lately, many researchers have been investigating how spleen elasticity changes in patients infected with hepatitis B virus or hepatitis C virus and in patients suffering from liver fibrosis, portal hypertension, esophageal varices or myelofibrosis. In this article, we review the role and current status of accessible qualitative ultrasound elastography methods, including recent advances in the evaluation of spleen stiffness and its clinical utility. As study results demonstrate, spleen stiffness correlates with liver fibrosis and is helpful in determining the level of fibrosis in the METAVIR scoring system. In patients infected with hepatitis B virus or hepatitis C virus, spleen stiffness increases even when liver elasticity remains unaltered. Furthermore, it is useful in diagnosing portal hypertension or predicting existence of esophageal varices. Moreover, in patients suffering from biliary atresia after Kasai portoenterostomy, spleen sonoelastography may be helpful in selecting patients for liver transplantation as well as for choosing the best strategy for portal vein reconstruction before liver transplantation. In myelofibrosis, spleen stiffness correlates with bone marrow fibrosis and may be used to assess the response to treatment. Spleen sonoelastography is also useful in the monitoring of transjugular intrahepatic portosystemic shunt function.

Non-invasive evaluation of portal hypertension using ultrasound elastography

Portal hypertension (PH) leads to serious complications, such as bleeding from gastroesophageal varices, ascites and portosystemic encephalopathy in patients with chronic liver disease (CLD). Gold standard methods for assessing PH and its complications include the measurement of hepatic venous pressure gradient and endoscopy; however, these are invasive, expensive and not available at all centres. Therefore, non-invasive alternatives have been the subject of extensive investigation over the last 20years. The present review focuses on the role of ultrasound elastography - a novel group of non-invasive techniques used to measure stiffness in target organs. In the context of CLD these methods are used to identify the presence of PH, its severity, and the risk of PH-related complications. The rationale, accumulated evidence, advantages and limitations of liver and spleen stiffness measurements evaluated by different ultrasound elastography techniques in patients with advanced CLD is discussed. Recent data regarding the use of ultrasound elastography techniques in patients with non-cirrhotic forms of PH are also described.

Virtual Touch™ Quantification to Diagnose and Monitor Liver Fibrosis in Hepatitis B and Hepatitis C: A NICE Medical Technology Guidance

Virtual Touch™ Quantification (VTq) is a software application used with Siemens Acuson ultrasound scanners to assess the stiffness of liver tissue. The National Institute for Health and Care Excellence (NICE) Medical Technologies Advisory Committee (MTAC) selected VTq for evaluation and invited the company to submit clinical and economic evidence. King's Technology Evaluation Centre, an External Assessment Centre (EAC) commissioned by NICE, independently assessed the evidence submitted. The EAC conducted its own systematic review, meta-analysis and economic analysis to supplement the company's submitted evidence. The meta-analyses comparing VTq and transient elastography (TE) with liver biopsy (LB) provided pooled estimates of liver stiffness and stage of fibrosis for the study populations (hepatitis B, hepatitis C or combined populations). When comparing significant fibrosis (Metavir score F ≥ 2) for both hepatitis B and C, VTq had slightly higher values for both sensitivity and specificity (77 and 81 %) than TE (76 and 71 %). The overall prevalence of cirrhosis (F4, combined populations) was similar with VTq and TE (23 vs. 23 %), and significant fibrosis (F ≥ 2) was lower for VTq than for TE (55 vs. 62 %). The EAC revised the company's de novo cost model, which resulted in a cost saving of £53 (against TE) and £434 (against LB). Following public consultation, taking into account submitted comments, NICE Medical Technology Guidance MTG27 was published in September 2015. This recommended the adoption of the VTq software to diagnose and monitor liver fibrosis in patients with hepatitis B or hepatitis C.

Diagnostic accuracy of contrast-enhanced computed tomography for esophageal varices in liver cirrhosis: a retrospective observational study

BACKGROUND AND AIM

Esophageal variceal bleeding is a life-threatening complication of liver cirrhosis. Upper gastrointestinal endoscopy was the gold standard for the diagnosis of esophageal varices (EVs). The study aimed to evaluate the accuracy of contrast-enhanced computed tomography (CT) in the diagnosis of EVs and moderate-severe EVs in patients with liver cirrhosis.

METHODS

Medical records in cirrhotic patients who were admitted to our hospital between June 2012 and June 2014 were retrospectively reviewed. Two observers reviewed the contrast-enhanced CT scans to evaluate the presence and diameter of EVs. Area under curve (AUC), sensitivity, and specificity were calculated.

RESULTS

A total of 52 cirrhotic patients were included in our study. According to the endoscopic results, 13.5% of these patients did not have any EVs, 11.5% had mild EVs, and 75% had moderate-severe EVs. The AUC of contrast-enhanced CT scans for the diagnosis of EVs was 0.835. The sensitivity and specificity were 95.56% and 71.43%, respectively. The AUC of contrast-enhanced T scans for the diagnosis of moderate-severe EVs was 0.821. When the cut-off value for the diameter of EVs on contrast-enhanced CT scans was 3.9 mm, the sensitivity and specificity were 89.74% and 69.23%, respectively.

CONCLUSIONS

Contrast-enhanced CT scans had a moderate diagnostic accuracy for EVs in liver cirrhosis. It might be useful to decrease the use of upper gastrointestinal endoscopy in clinical practice.

Spleen Stiffness Is Superior to Liver Stiffness for Predicting Esophageal Varices in Chronic Liver Disease: A Meta-Analysis

Background and Aims

Liver stiffness (LS) and spleen stiffness (SS) are two most widely accessible non-invasive parameters for predicting esophageal varices (EV), but the reported accuracy of the two predictors have been inconsistent across studies. This meta-analysis aims to evaluate the diagnostic performance of LS and SS measurement for detecting EV in patients with chronic liver disease (CLD), and compare their accuracy.

Methods

Pubmed/Medline, Embase, Cochrane Library and Ovid were searched for all studies assessing SS and LS simultaneously in EV diagnosis. A total of 16 studies including 1892 patients were included in this meta-analysis, and the pooled statistical parameters were calculated using the bivariate mixed effects models.

Results

In detection of any EV, for LS measurement, the summary sensitivity was 0.83 (95% confidence interval [CI]: 0.78–0.87), and the specificity was 0.66 (95% CI: 0.60–0.72). While for SS measurement, the pooled sensitivity and specificity was 0.88 (95% CI: 0.83–0.92) and 0.78 (95% CI: 0.73–0.83). The summary receiver operating characteristic (SROC) curve values of LS and SS were 0.81 (95% CI: 0.77–0.84) and 0.88 (95% CI: 0.85–0.91) respectively, and the results had statistical significance (P<0.01). The diagnostic odds ratio (DOR) of SS (25.73) was significantly higher than that of LS (9.54), with the relative DOR value was 2.48 (95%CI: 1.10–5.60), P<0.05.

Conclusions

Under current techniques, SS is significantly superior to LS for identifying the presence of EV in patients with CLD. SS measurement may help to select patients for endoscopic screening.

ARFI: from basic principles to clinical applications in diffuse chronic disease-a review

Abstract

The many factors influencing the shear wave velocity (SWV) measured with Acoustic Radiation Force Impulse (ARFI) are examined in order to define the most correct examination technique. In particular, attention is given to the information achieved by experimental models, such as phantoms and animal studies. This review targets the clinical applications of ARFI in the evaluation of chronic diffuse disease, especially of liver and kidneys. The contribution of ARFI to the clinical workout of these patients and some possible perspectives are described.

Teaching Points

• Stiffness significantly varies among normal and abnormal biological tissues.

• In clinical applications physical, geometrical, anatomical and physiological factors influence the SWV.

• Elastographic techniques can quantify fibrosis, which is directly related to stiffness.

• ARFI can be useful in chronic diffuse disease of liver and kidney.

Measuring spleen stiffness to predict varices in chronic hepatitis B cirrhotic patients with or without receiving non-selective beta-blockers

OBJECTIVES

we aimed to investigate the accuracy of liver (LSM) spleen stiffness measurement (SSM) with transient elastography (TE) to predict varices in the presence of non-selective beta-blockers (NSBB).

METHODS

In this cross-sectional study of consecutive patients with chronic hepatitis B (CHB) and cirrhosis, all patients underwent TE and upper endoscopic examinations. LSM and SSM in predicting varices in patients receiving and not receiving NSBB were evaluated.

RESULTS

Altogether 144 CHB patients (29 receiving NSBB; 35 with any varices, 31 and 11 with esophageal and gastric varices, respectively) were recruited. Their mean LSM and SSM were 13.3 ± 9.0 kPa and 32.8 ± 19.2 kPa, respectively. The correlation between LSM and SSM was better in the NSBB subgroup (r = 0.525, P = 0.003) than its counterpart (r = 0.329, P  < 0.001). The area under receiver operating characteristic curve (AUROC) of LSM and SSM for any varices was 0.675 and 0.685 (P = 0.002 and 0.001), respectively. SSM of 18.9 kPa had a negative predictive value of 92.1% and negative likelihood ratio of 0.27 for ruling out any varices; and SSM of 54.9 kPa had a positive predictive value of 56.5% and a positive likelihood ratio of 4.05 to rule in varices. The AUROC of LSM for varices was 0.742 and 0.549 in patients with or without NSBB, respectively; the corresponding AUROC of SSM was 0.572 and 0.603, respectively.

CONCLUSIONS

SSM only has modest accuracy to predict varices independent of NSBB use. An SSM cutoff value of 18.9 kPa may be adopted to achieve a high negative predictive value to rule out varices.

Non-invasive assessment of liver fibrosis in patients with alcoholic liver disease using acoustic radiation force impulse elastography

OBJECTIVES

To investigate the diagnostic performance of the acoustic radiation force impulse (ARFI) elastography for the assessment of the liver fibrosis in alcoholic liver disease (ALD).

METHODS

We included 112 patients with ALD in whom liver biopsy, ARFI elastography, and aspartate-to-platelet ratio index (APRI) measurements were performed.

RESULTS

ARFI elastography correlated significantly with histological fibrosis (r = 0.685, P < 0.001) in patients with ALD. The diagnostic accuracies expressed as areas under receiver operating characteristic (AUROC) curves for ARFI elastography and APRI were 0.846 and 0.763 for the diagnosis of significant fibrosis (S ≥ 2), 0.875 and 0.688 for the diagnosis of severe fibrosis (S ≥ 3), and 0.893 and 0.648 for the diagnosis of liver cirrhosis, respectively. The AUROC values of ARFI elastography were significantly better than those of APRI for predicting severe fibrosis (P = 0.02) and cirrhosis (P = 0.04). The optimum cutoff values for ARFI elastography were 1.33 m/s for S ≥ 2, 1.40 m/s for S ≥ 3, and 1.65 m/s for S = 4 in patients with elevated alanine aminotransferase (ALT) levels; these decreased to 1.24 m/s for S ≥ 2, 1.27 m/s for S ≥ 3, and 1.41 m/s for S = 4 in patients with normal ALT.

CONCLUSION

ARFI elastography is an acceptable method for predicting the severity of fibrosis in patients with ALD. ARFI elastography is influenced by elevated aminotransferase levels in ALD.

Acoustic radiation force impulse quantification of spleen elasticity for assessing liver fibrosis

PURPOSE

The purpose of this study is to assess the correlation between liver fibrosis and spleen stiffness measured by ARFI in patients with chronic viral hepatitis (B or C) and to explore the possible complementary role of spleen and liver ARFI in grading liver fibrosis.

METHODS

84 subjects (51 patients, 33 healthy volunteers) were enrolled. ARFI of the spleen and the liver was performed. Patients subsequently underwent liver biopsy for grading liver fibrosis according to Knodell scoring system. Multivariate logistic regression and decision tree analysis were adopted to test the relationship between spleen and liver stiffness (independent variables) and liver fibrosis (F1< vs. ≥F3). Leave-One-Out Cross-Validation was used for validating the predictive classification models. Area under the ROC curve (AUROCC) was used as accuracy metric.

RESULTS

Spleen ARFI was able to discriminate early (F1) from severe (≥F3) liver fibrosis with an optimal cut-off of 3.05 m/s: AUROCC 0.807, cross-validated AUROCC 0.614. Liver ARFI was superior to spleen ARFI, using a cut-off of 2.11 m/s: AUROCC 0.879, cross-validated AUROCC 0.672. Neither spleen nor liver ARFI was able to differentiate healthy volunteers from F1 patients. Odds ratios derived from logistic regression were 23.1 and 9.9 for liver and spleen ARFI, respectively; resulting AUROCC was 0.905 (cross-validated 0.848). A decision tree considering the sequential use of liver and spleen ARFI with cut-off of 2.14 and 3.39 m/s, respectively, resulted in AUROCC of 0.903 (cross-validated 0.7).

CONCLUSIONS

Spleen ARFI has the potential to discriminate early from severe liver fibrosis. Spleen and liver ARFI, when combined, show a better discriminative power than liver ARFI alone.

Magnetic resonance elastography and acoustic radiation force impulse for staging hepatic fibrosis: a meta-analysis

PURPOSE

Elastography is a non-invasive method to quantify fibrosis based on tissue mechanical properties. We performed a meta-analysis to assess the diagnostic accuracy of two such techniques: Acoustic Radiation Force Impulse Imaging (ARFI) or Magnetic Resonance Elastography (MRE) for staging hepatic fibrosis.

MATERIALS AND METHODS

Literature databases were searched until June 2013. Inclusion criteria were evaluation of MRE or ARFI, liver biopsy, and reported sensitivity and specificity. A random effects model was used to combine sensitivity and specificity, from which positive (LR+) and negative (LR-) likelihood ratios, diagnostic odds ratios, and area under receiver operating characteristics curve (AUROC) were derived. Differences between MRE and ARFI were compared with t tests (P < 0.05 considered significant).

RESULTS

Eleven MRE studies including 982 patients and fifteen ARFI studies including 2,128 patients were selected. AUROC for MRE staging fibrosis were 0.94, 0.97, 0.96, and 0.97 for F1-F4, respectively, whereas AUROC for ARFI staging were 0.82, 0.85, 0.94, and 0.94 for F1-F4, respectively. Significance was found in AUROC between MRE and ARFI for the diagnosis of stage 1 and 2 fibrosis.

CONCLUSION

MRE is more accurate than ARFI with a higher combination of sensitivity, specificity, LR, and AUROC particularly in diagnosing early stages of hepatic fibrosis.

Liver and spleen stiffness and other noninvasive methods to assess portal hypertension in cirrhotic patients: a review of the literature

Portal hypertension (PH) is one of the most important causes of morbidity and mortality in patients with chronic liver disease. PH measurement is crucial to stage and predict the clinical outcome of liver cirrhosis. Measurement of hepatic vein pressure gradient is considered the gold standard for assessment of the degree of PH; however, it is an invasive method and has not been used widely. Thus, noninvasive methods have been proposed recently. We critically evaluated serum markers, abdominal ultrasonography, and particularly liver and spleen stiffness measurement, which represent the more promising methods to stage PH degree and to assess the presence/absence of esophageal varices (EV). A literature search was carried out on MEDLINE, EMBASE, Web of Science, and Scopus for articles and abstracts. The search terms used included 'liver cirrhosis', 'portal hypertension', 'liver stiffness', 'spleen stiffness', 'ultrasonography', and 'portal hypertension serum biomarker'. The articles cited were selected on the basis of their relevance to the objective of the review. The results of available studies indicate that individually, these methods have a mild accuracy in predicting the presence of EV, and thus they cannot substitute endoscopy to predict EV. When these tests were used in combination, their accuracy increased. In addition to the PH staging, several serum markers and spleen stiffness measurement can predict the clinical outcome of liver cirrhosis with a good accuracy, comparable to that of hepatic vein pressure gradient. In the future, noninvasive methods could be used to select patients requiring further investigations to identify the best tailored clinical management.

Normal values of spleen stiffness in healthy children assessed by acoustic radiation force impulse imaging (ARFI): comparison between two ultrasound transducers

BACKGROUND

Portal hypertension, a major complication of hepatic fibrosis, can affect the stiffness of the spleen.

OBJECTIVE

To suggest normal values of spleen stiffness determined by acoustic radiation force impulse imaging in healthy children and to compare measurements using two different US probes.

MATERIALS AND METHODS

In a prospective study, 60 healthy children between 1 day and 14 years of age were assigned to four age groups with 15 children in each. Measurements were performed using two transducers (convex 4C1 and linear 9L4), and 10 measurements were obtained in each child, 5 with each probe.

RESULTS

The mean splenic shear wave velocities were 2.17 m/s (SD 0.35, 95% CI 2.08-2.26) with the 4C1 probe and 2.15 m/s (SD 0.23, 95% CI 2.09-2.21) with the 9L4 probe (not significant).

CONCLUSION

We found normal values for spleen stiffness with no difference in the mean values obtained using two types of US transducers, but with higher variability using a convex compared to a linear transducer.

Liver and spleen elastography using supersonic shear imaging for the non-invasive diagnosis of cirrhosis severity and oesophageal varices

BACKGROUND

Elastography is a promising non-invasive approach for assessing liver fibrosis. We assessed diagnostic performances of liver and spleen stiffness using supersonic shear imaging for diagnosing cirrhosis severity and oesophageal varices.

METHODS

401 consecutive cirrhotic patients were prospectively enrolled from November 2012 to March 2014. All patients underwent liver and spleen stiffness measurement with supersonic shear imaging and Fibroscan.

RESULTS

Failures of measurement were 6.2% and 29.2% for liver and spleen stiffness (supersonic shear imaging), and 18.4% for liver stiffness (Fibroscan). Liver and spleen stiffness were correlated with severity of cirrhosis, with values increasing according to Child-Pugh subclasses and presence of complications. With a negative predictive value ≥90%, liver stiffness cut-offs for high-risk oesophageal varices, history of ascites, Child-Pugh B/C, variceal bleeding and clinical decompensation were 12.8, 19, 21.4, 30.5, and 39.4 kPa, respectively. Areas under the curve of spleen and liver stiffness (supersonic shear imaging), and liver stiffness (Fibroscan) were 0.80, 0.77 and 0.73 respectively for detection of oesophageal varices.

CONCLUSION

Liver stiffness using supersonic shear imaging is a relevant diagnostic tool for assessing cirrhosis severity and its complications. Spleen stiffness shows promising results for the detection of oesophageal varices but is not yet sufficiently robust for clinical practice owing to high failure rates.

Liver stiffness measured by acoustic radiation force impulse elastography reflects the severity of liver damage and prognosis in patients with acute liver failure

AIM

We measured liver stiffness (LS) in patients with acute liver failure (ALF) using acoustic radiation force impulse (ARFI) elastography and investigated the usefulness of measuring LS for predicting the prognosis of ALF patients.

METHODS

From April 2010 to December 2013, we evaluated 63 patients with acute liver disease. The subjects included 41 patients with acute hepatitis (AH), 16 patients with severe AH (SAH), who had no hepatic encephalopathy despite plasma prothrombin time of 40% or less, and six patients with fulminant hepatitis (FH) diagnosed according to the criteria of the Japanese Study Group. The relationships among shear wave velocity (SWV), clinical diagnosis, liver function tests and prognosis were evaluated. Receiver-operator curve (ROC) analysis was performed to investigate whether ARFI elastography exhibits potential usefulness for the prediction of FH.

RESULTS

The mean SWV on admission were 1.98 ± 0.55, 2.61 ± 0.58 and 3.66 ± 0.86 m/s in the AH, SAH and FH groups, respectively. The SWV was significantly higher in the FH group than in the other groups (P < 0.001), and in the SAH group than in the AH group (P = 0.002). The area under the ROC for predicting FH was 0.924 (sensitivity, 83.3%; specificity, 93.0%). The SWV was significantly increased in non-survivors, while remaining decreased in survivors (P = 0.002).

CONCLUSION

The SWV measured by ARFI elastography reflects severity of liver damage, and serial changes in SWV predict the prognosis of ALF patients. The SWV is an early and precise biomarker of FH.

A novel model to predict esophageal varices in patients with compensated cirrhosis using acoustic radiation force impulse elastography

BACKGROUND & AIMS

Few noninvasive methods can accurately identify esophageal varices (EVs) in patients with compensated cirrhosis. We developed and validated a novel, acoustic radiation force impulse (ARFI) elastography-based prediction model for high-risk EVs (HEVs) in patients with compensated cirrhosis.

METHODS

A total of 143 patients with compensated cirrhosis between February, 2010 and February, 2013 (training set) and 148 between June, 2010 and May, 2013 (validation set) who underwent ARFI elastography and endoscopy were prospectively recruited. Independent predictors of HEVs were used to construct a prediction model.

RESULTS

Based on multivariate analysis, we developed two new statistical models, a varices risk score and ARFI-spleen diameter-to-platelet ratio score (ASPS), the latter of which was calculated as ARFI velocity × spleen diameter/platelet count. The area under receiver operating characteristic curve (AUROC) of the varices risk score and ASPS to predict HEVs were 0.935 (95% confidence interval [CI] 0.882-0.970) and 0.946 (95% CI 0.895-0.977), respectively. When ASPS, a simpler model with a higher AUROC, was applied in the validation set, acceptable diagnostic accuracy for HEVs was observed (AUROC = 0.814 [95% CI 0.743-0.885]). To detect HEVs, a negative predictive value of 98.3% was achieved at ASPS <2.83, whereas a positive predictive value of 100% was achieved at ASPS >5.28.

CONCLUSIONS

ASPS, a novel noninvasive ARFI-based prediction model, can accurately identify HEVs in patients with compensated cirrhosis. ASPS <2.83 may safely rule out the presence of HEVs, whereas patients with ASPS >5.28 should be considered for endoscopic examinations or appropriate prophylactic treatment.

Stratification of patients with liver fibrosis using dual-energy CT

Assessing the severity of liver fibrosis has direct clinical implications for patient diagnosis and treatment. Liver biopsy, typically considered the gold standard, has limited clinical utility due to its invasiveness. Therefore, several imaging-based techniques for staging liver fibrosis have emerged, such as magnetic resonance elastography (MRE) and ultrasound elastography (USE), but they face challenges that include limited availability, high cost, poor patient compliance, low repeatability, and inaccuracy. Computed tomography (CT) can address many of these limitations, but is still hampered by inaccuracy in the presence of confounding factors, such as liver fat. Dual-energy CT (DECT), with its ability to discriminate between different tissue types, may offer a viable alternative to these methods. By combining the "multi-material decomposition" (MMD) algorithm with a biologically driven hypothesis we developed a method for assessing liver fibrosis from DECT images. On a twelve-patient cohort the method produced quantitative maps showing the spatial distribution of liver fibrosis, as well as a fibrosis score for each patient with statistically significant correlation with the severity of fibrosis across a wide range of disease severities. A preliminary comparison of the proposed algorithm against MRE showed good agreement between the two methods. Finally, the application of the algorithm to longitudinal DECT scans of the cohort produced highly repeatable results. We conclude that our algorithm can successfully stratify patients with liver fibrosis and can serve to supplement and augment current clinical practice and the role of DECT imaging in staging liver fibrosis.