Non-invasive assessment of liver fibrosis with impulse elastography: comparison of Supersonic Shear Imaging with ARFI and FibroScan®

Adipose tissue fibrosis assessed by high resolution ex vivo MRI as a hallmark of tissue alteration in morbid obesity

To determine whether magnetic resonance imaging (MRI) when used in an optimal ex vivo setting can help detecting and quantifying the 3D fibrosis fraction in human subcutaneous adipose tissue (SAT) samples, as compared to histology. This prospective observational study was approved by our institutional review board 3D MRI acquisitions were performed at 4.0 T (Bruker) on XX human SAT samples (around 1 cm3) collected from biopsy in morbidly obese patients. Such acquisitions included saturation-recovery T1 mapping (spatial resolution: 200 µm, acquisition time: ~16 minutes) and DIXON imaging (spatial resolution: 200 µm, acquisition time: ~20 minutes). After MRI, histological quantification of fibrosis was performed using picrosirius staining. T1 maps were clustered based on a k-means algorithm allowing quantification of fibrosis within the adipose tissue and percentage of fibrosis over the entire sample volume was calculated. Fat maps were computed from DIXON in-phase and out-of-phase images. The 3D MRI fibrosis percentage within the SAT samples were comprised between 6% and 15%. Excellent correlations and levels of agreement were observed between single slice MRI and histology (r=0.9, P=0.08) and between 3D MRI and histology in terms fibrosis percentages within SAT samples (r=0.9, P=0.01). High Field ex vivo MRI was able to quantify fibrosis in human SAT samples with high agreement with histology and moreover to provide 3D SAT fibrosis quantification avoiding histological sampling errors.

Quantification of Liver Fibrosis, Steatosis, and Viscosity Using Multiparametric Ultrasound in Patients with Non-Alcoholic Liver Disease: A "Real-Life" Cohort Study

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide. This study aimed to evaluate the performance of four ultrasound-based techniques for the non-invasive multiparametric (MPUS) assessment of liver fibrosis (LF), steatosis (HS), and inflammation in patients with NAFLD. We included 215 consecutive adult patients with NAFLD (mean age: 54.9 ± 11.7; 54.5% were male), in whom LF, HS, and viscosity were evaluated in the same session using four new ultrasound-based techniques embedded on the Aixplorer MACH 30 system: ShearWave Elastography (2D-SWE.PLUS), Sound Speed Plane-wave UltraSound (SSp.PLUS), Attenuation Plane-wave UltraSound (Att.PLUS), and Viscosity Plane-wave UltraSound (Vi.PLUS). Transient Elastography (TE) with Controlled Attenuation Parameter (CAP) (FibroScan) were considered as control. All elastographic measurements were performed according to guidelines. Valid liver stiffness measurements (LSM) were obtained in 98.6% of patients by TE, in 95.8% of patients by 2D-SWE.PLUS/Vi.PLUS, and in 98.1% of patients by Att.PLUS/SSp.PLUS, respectively. Therefore, 204 subjects were included in the final analysis. A strong correlation between LSMs by 2D-SWE.PLUS and TE (r = 0.89) was found. The best 2D-SWE.PLUS cut-off value for the presence of significant fibrosis (F ≥ 2) was 7 kPa. Regarding steatosis, SSp.PLUS correlated better than Att.PLUS with CAP values: (r = -0.74) vs. (r = 0.45). The best SSp.PLUS cut-off value for predicting the presence of significant steatosis was 1524 m/s. The multivariate regression analysis showed that Vi.PLUS values were associated with BMI and LSM by 2D-SWE.PLUS. In conclusion, MPUS was useful for assessing fibrosis, steatosis, and inflammation in a single examination in patients with NAFLD.

Shear wave-based sound touch elastography in liver fibrosis assessment for patients with autoimmune liver diseases

BACKGROUND

Shear wave-based ultrasonic elastography (USE) has been widely used for the assessment of liver fibrosis in patients with chronic liver diseases (CLD). However, diagnostic criteria and accuracy vary between different etiologies and specific elastography techniques. We aimed to evaluate the tissue stiffness measured by shear wave-based sound touch elastography (STE) in staging liver fibrosis in patients with autoimmune liver diseases (AILD).

METHODS

One hundred and two AILD patients who had undergone STE liver stiffness measurements (LSMs) by using a Resona 7 ultrasound system were retrospectively studied. With the Scheuer liver fibrosis staging system as the reference, we investigated the diagnostic performance and cutoff values of STE measured liver stiffness in staging liver fibrosis through receiver operating characteristic (ROC) curve analysis. Moreover, comparisons of areas under the curve (AUCs) were made between LSMs and calculated biomarker scores, including the aspartate aminotransferase (AST)-to-platelet ratio index (APRI), and fibrosis-4 (FIB-4) index.

RESULTS

Median LSMs increased with the advancing fibrosis stages with values of 6.89 kPa (1.51 m/s), 8.00 kPa (1.63 m/s), 9.60 kPa (1.79 m/s), 11.37 kPa (1.95 m/s) and 14.50 kPa (2.20 m/s), from stage 0 to stage 4 respectively. The cutoff values of STE for identifying significant fibrosis (≥ stage 2), severe fibrosis (≥ stage 3) and cirrhosis (stage 4) were 9.07 kPa (1.74 m/s), 9.97 kPa (1.82 m/s) and 10.48 kPa (1.87 m/s), respectively, with corresponding sensitivity of 79.1%, 93.3%, and 100%; specificity of 80.0%, 70.8% and 71.8%. The AUCs of LSMs in identifying fibrosis ≥ stage 2, ≥ stage 3 and stage 4 (0.82, 0.87, and 0.91, respectively) were significantly higher than that of APRI (0.67, 0.64, and 0.72, respectively) and FIB-4 (0.70, 0.68, and 0.75, respectively) (all P<0.05).

CONCLUSIONS

LSM obtained by STE exhibited its good capability to evaluate liver fibrosis stages in patients with AILD. As a noninvasive modality for liver fibrosis staging, STE is superior to APRI and FIB-4 biomarker scores.

What's New in Hepatic Steatosis

Hepatic steatosis can lead to liver cancer, cirrhosis, and portal hypertension. There are two main types, non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease. The detection and quantification of hepatic steatosis with lifestyle changes can slow the evolution from NAFLD to steatohepatitis. Currently, the gold standard for the quantification of fat in the liver is biopsy, has some limitations. Hepatic steatosis is frequently detected during cross sectional imaging. Ultrasound (US), Computed Tomography (CT), and Magnetic Resonance Imaging (MRI) provide noninvasive assessment of liver parenchyma and can detect fat infiltration in the liver. However, the non-invasive quantification of hepatic steatosis by imaging has been challenging. Recent MRI techniques show great promise in the detection and quantification of liver fat. The aim of this article is to review the utilization of non-invasive imaging modalities for the detection and quantification of hepatic steatosis, to evaluate their advantages and limitations.

Elastografía en tiempo real (Supersonic), experiencia de un centro en Bogotá

Introducción: la elastografía en tiempo real, 2D-SWE (Supersonic), es una prueba no invasiva que se utiliza para determinar la elasticidad del hígado y, de esa forma, calcular el grado de fibrosis hepática. En Colombia, la prueba se introdujo en 2016 y no existen hasta el momento estudios del comportamiento de la prueba en todos los pacientes hepáticos, solo se han publicado en pacientes sanos y cirróticos. Objetivo: analizar la experiencia de la aplicación de la elastografía en tiempo real, en sujetos atendidos en el centro de enfermedades hepáticas y digestivas de Bogotá, Colombia. Materiales y métodos: estudio descriptivo retrospectivo de una cohorte de sujetos atendidos entre marzo de 2016 y julio de 2017. Se realizó una historia clínica completa y una prueba de elastografía en tiempo real (Supersonic). Resultados: se incluyeron 654 sujetos, con una mediana de edad de 55 años (rango intercuartílico [RIC]: 45-64). La mediana de valores de fibrosis expresada en kilopascales (kPs) fue de 8,3, con un promedio de 5 mediciones. Se observó una diferencia significativa en el grado de fibrosis entre los grupos de edad y en relación con el diagnóstico final, donde se evidenció una mayor fibrosis en el grupo de enfermedades colestásicas (autoinmune, colangitis biliar primaria [CBP] y superposición autoinmune-CBP). La tasa global de fracaso fue menor al 1 %. Conclusiones: es la primera descripción del comportamiento de la prueba a nivel nacional. Los valores de rigidez hepática observados en los diferentes estadios demuestran la utilidad de la prueba para la determinación de la fibrosis hepática en pacientes con diferentes patologías.

Liver stiffness as measured by two-dimensional shear wave elastography overestimates the stage of fibrosis in patients with chronic hepatitis B and hepatic steatosis

Two-dimensional shear wave elastography (2D-SWE) is a non-invasive technique for measuring liver stiffness (LS) and is used to assess the degree of hepatic fibrosis in patients with chronic hepatitis B (CHB). Despite its usefulness, several factors, other than hepatic fibrosis, can affect its diagnostic accuracy. Hepatic steatosis (HS) is a common lesion in CHB that has increasingly been getting attention in the field of disease development; however, its influence on the measurement of LS remains unclear. We aimed to determine whether HS affects the diagnostic accuracy of 2D-SWE in patients with CHB. Serum parameters and LS values were obtained from 161 patients with CHB. The degrees of hepatic fibrosis and inflammatory activity were estimated based on the METAVIR Cooperative Study Group criteria, and the extent of HS was defined as the percentage of hepatocytes containing fat droplets using oil red staining. We found that LS values were independently correlated with HS in the early stages of hepatic fibrosis (F0-F2 or F0-3). Furthermore, LS values in patients with significant steatosis (S≥10%) were higher than the counterpart in fibrosis stages F0-2 (6.82±1.57 vs. 7.92±1.99; p=0.010) and F0-3 (7.18±1.84 vs. 8.25±1.91; p=0.007). Therefore, false positive rates (FPRs) in the diagnosis of advanced fibrosis (16.00% vs. 37.04%, p=0.037) and cirrhosis (6.67% vs. 21.62%, p=0.030) were higher in patients with significant steatosis. In conclusion, the use of 2D-SWE in the measurement of LS overestimates the stage of hepatic fibrosis in CHB patients with HS>10%. This should be taken into consideration to combine LS results with other non-invasive parameters to improve its accuracy.

Electronic Point Spread Function Rotation Using a Three-Row Transducer for ARFI-Based Elastic Anisotropy Assessment: In Silico and Experimental Demonstration

Degree of anisotropy (DoA) of mechanical properties has been assessed as the ratio of acoustic radiation force impulse (ARFI)-induced peak displacements (PDs) achieved using spatially asymmetric point spread functions (PSFs) that are rotated 90° to each other. Such PSF rotation has been achieved by manually rotating a linear array transducer, but manual rotation is cumbersome and prone to misalignment errors and higher variability in measurements. The purpose of this work is to evaluate the feasibility of electronic PSF rotation using a three-row transducer, which will reduce variability in DoA assessment. A Siemens 9L4, with 3×192 elements, was simulated in Field II to generate spatially asymmetric ARFI PSFs that were electronically rotated 63° from each other. Then, using the finite element method (FEM), PD due to the ARFI excitation PSFs in 42 elastic, incompressible, transversely isotropic (TI) materials with shear moduli ratios of 1.0-6.0 were modeled. Finally, the ratio of PDs achieved using the two rotated PSFs was evaluated to assess elastic DoA. DoA increased with increasing shear moduli ratios and distinguished materials with 17% or greater difference in shear moduli ratios (Wilcoxon, ). Experimentally, the ratio of PDs achieved using ARFI PSF rotated 63° from each other distinguished the biceps femoris muscle from two pigs, which had median shear moduli ratios of 4.25 and 3.15 as assessed by shear wave elasticity imaging (SWEI). These results suggest that ARFI-based DoA assessment can be achieved without manual transducer rotation using a three-row transducer capable of electronically rotating PSFs by 63°. It is expected that electronic PSF rotation will facilitate data acquisitions and improve the reproducibility of elastic anisotropy assessments.

Estimation of liver elasticity using the finite element method and four-dimensional computed tomography images as a biomarker of liver fibrosis

PURPOSE

Current radiotherapy planning procedures are generally designed based on anatomical information only and use computed tomography (CT) images that do not incorporate organ-functional information. In this study, we developed a method for estimating liver elasticity using the finite element method (FEM) and four-dimensional CT (4DCT) images acquired during radiotherapy planning, and we subsequently evaluated its feasibility as a biomarker for liver fibrosis.

MATERIALS AND METHODS

Twenty patients who underwent 4DCT and ultrasound-based transient elastography (UTE) were enrolled. All patients had chronic liver disease or cirrhosis. Liver elasticity measurements of the UTE were performed on the right lobe of the patient's liver in 20 patients. The serum biomarkers of the aspartate aminotransferase (AST)-to-platelet ratio index (APRI) and fibrosis-4 index (FIB-4) were available in 18 of the 20 total patients, which were measured within 1 week after undergoing 4DCT. The displacement between the 4DCT images obtained at the endpoints of exhalation and inspiration was determined using the actual (via deformable image registration) and simulated (via FEM) respiration-induced displacement. The elasticity of each element of the liver model was optimized by minimizing the error between the actual and simulated respiration-induced displacement. Then, each patient's estimated liver elasticity was defined as the mean Young's modulus of the liver's right lobe and that of the whole liver using the estimated elasticity map. The estimated liver elasticity was evaluated for correlations with the elasticity obtained via UTE and with two serum biomarkers (APRI and FIB-4).

RESULTS

The mean ± standard deviation (SD) of the errors between the actual and simulated respiration-induced displacement in the liver model was 0.54 ± 0.33 mm. The estimated liver's right lobe elasticity was statistically significantly correlated with the UTE (r = 0.87, P < 0.001). Furthermore, the estimated whole liver elasticity was statistically significantly correlated with the UTE (r = 0.84, P < 0.001), APRI score (r = 0.62, P = 0.005), and FIB-4 score (r = 0.54, P = 0.021).

CONCLUSION

In this study, liver elasticity was estimated through FEM-based simulation and actual respiratory-induced liver displacement obtained from 4DCT images. Furthermore, we assessed that the estimated elasticity of the liver's right lobe was strongly correlated with the UTE. Therefore, the estimated elasticity has the potential to be a feasible imaging biomarker for assessing liver fibrosis using only 4DCT images without additional inspection or equipment costs. Because our results were derived from a limited sample of 20 patients, it is necessary to evaluate the accuracy of elasticity estimation for each liver segment on larger groups of biopsied patients to utilize liver elasticity information for radiotherapy planning.

Measurement of liver and spleen stiffness as complementary methods for assessment of liver fibrosis in autoimmune hepatitis

BACKGROUND AND AIMS

Liver stiffness measurements (LSM), commonly performed by transient elastography (TE) or two-dimensional shear wave elastography (2D-SWE), are used to quantify liver fibrosis. Active hepatitis, a hallmark of autoimmune hepatitis (AIH), could bias LSM. This bias might be overcome by measurement spleen 2D-SWE. Here, we compare liver and spleen 2D-SWE to TE and liver biopsy (LB) in prospectively recruited patients with AIH.

METHODS

We analysed liver and spleen 2D-SWE in relation to liver TE in 90 patients treated ≥ 6 months for AIH. Liver and spleen 2D-SWE were also compared to LB in 63 individuals with AIH. Finally, we evaluated these tools in 220 patients with AIH and during 18 months follow-up.

RESULTS

Liver 2D-SWE correlated with surrogate markers of active hepatitis (ALT and IgG, both P < .001) but there was no link between spleen 2D-SWE and ALT. Liver 2D-SWE, but not spleen 2D-SWE, was associated with histopathological inflammatory score (P < .01). When compared to LB, the optimal cut-offs for detecting cirrhosis by liver and spleen 2D-SWE were 16.1 kPa (AUROC 0.93) and 29.8 kPa (AUROC 0.95), respectively. In patients with active hepatitis the combined diagnostic approach including liver and spleen 2D-SWE had significantly better AUROC for detecting cirrhosis than liver 2D-SWE alone.

CONCLUSIONS

Liver and spleen 2D-SWE are reliable complementary methods for the diagnosis of advanced fibrosis in AIH. Spleen 2D-SWE seems to be less biased by inflammation and could facilitate fibrosis assessment in therapy-naïve patients or in the presence of active hepatitis.

A review of physical and engineering factors potentially affecting shear wave elastography

It has been recognized that tissue stiffness provides useful diagnostic information, as with palpation as a screening for diseases such as cancer. In recent years, shear wave elastography (SWE), a technique for evaluating and imaging tissue elasticity quantitatively and objectively in diagnostic imaging, has been put into practical use, and the amount of clinical knowledge about SWE has increased. In addition, some guidelines and review papers regarding technology and clinical applications have been published, and the status as a diagnostic technology is in the process of being established. However, there are still unclear points about the interpretation of shear wave speed (SWS) and converted elastic modulus in SWE. To clarify these, it is important to investigate the factors that affect the SWS and elastic modulus. Therefore, physical and engineering factors that potentially affect the SWS and elastic modulus are discussed in this review paper, based on the principles of SWE and a literature review. The physical factors include the propagation properties of shear waves, mechanical properties (viscoelasticity, nonlinearity, and anisotropy), and size and shape of target tissues. The engineering factors include the region of interest depth and signal processing. The aim of this review paper is not to provide an answer to the interpretation of SWS. It is to provide information for readers to formulate and verify the hypothesis for the interpretation. Therefore, methods to verify the hypothesis for the interpretation are also reviewed. Finally, studies on the safety of SWE are discussed.

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

Purpose

This study prospectively assessed the performance of liver stiffness measurements using point shear-wave elastography (p-SWE) in comparison with transient elastography (TE) in patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD).

Methods

Fifty-six consecutive adult patients with a histological diagnosis of NAFLD prospectively underwent TE and p-SWE on the same day. The median of 10 measurements (SWE-10), the first five (SWE-5), and the first three (SWE-3) measurements were analyzed for p-SWE. Liver biopsy was considered as the reference standard for liver fibrosis grade. Receiver operating characteristic (ROC) curves and areas under the ROC curves (AUROCs) were calculated to assess the performance of TE and p-SWE for the diagnosis of significant (F2-F4) and advanced fibrosis (F3-F4).

Results

Forty-six patients (27 men, 19 women; mean age, 54.7±9.1 years) had valid p-SWE and TE measurements. Twenty-seven patients (58.7%) had significant fibrosis and 18 (39.1%) had advanced fibrosis. For significant fibrosis, both SWE-10 (AUROC, 0.787; P=0.002) and SWE-5 (AUROC, 0.809; P=0.001) provided higher diagnostic performance than TE (AUROC, 0.719; P=0.016) and SWE-3 (AUROC, 0.714; P=0.021), albeit without statistical significance (P=0.301). For advanced fibrosis, SWE-5 showed higher diagnostic performance (AUROC, 0.809; P<0.001) than TE (AUROC, 0.799; P<0.001), SWE-10 (AUROC, 0.797; P<0.001), and SWE-3 (AUROC, 0.736; P=0.003), although the differences were not statistically significant (P=0.496). The optimal SWE-10 and SWE-5 cutoff values were ≥8.4 and ≥7.8 for significant fibrosis, and ≥9.1 and ≥8.8 for advanced fibrosis, respectively.

Conclusion

TE and p-SWE showed similar performance for the diagnosis of significant and advanced fibrosis in NAFLD patients.

[Magnetic resonance elastography of the liver : Worth knowing for clinical routine]

BACKGROUND

Magnetic resonance elastography (MRE) is a noninvasive, quantitative, MRI-based method to evaluate liver stiffness. Beside biopsy and ultrasound elastography, this imaging method plays in many places a significant role in the detection and additive characterization of chronic liver disease.

OBJECTIVES, MATERIALS AND METHODS

Based on the literature, a brief review of the underlying method and the commercially available products is given. Furthermore, the practical procedure, the analysis, and the interpretation of clinically relevant questions are illustrated and a comparison with ultrasound elastography is provided.

RESULTS

This relative "young" MRI method allows extensive evaluation of mechanical properties of the liver and is an important diagnostic tool especially in follow-up examinations. The MRE of the liver is with a maximum technical failure rate of 5.8% a robust technique with high accuracy and an excellent re-test reliability as well as intra- and interobserver reproducibility. There is a high diagnostic certainty within the framework of most important clinical indications, the quantification of fibrosis, and with a very good correlation with the "gold standard" biopsy.

CONCLUSION

Based on its rising clinical relevance and the broad usage, MRE of the liver is increasingly used in many centers and in routine liver protocols. Therefore, basic knowledge of this method is essential for every radiologist.

Development of a novel glycated protein-based fibrosis prediction score for determination of significant liver fibrosis in HCV-infected patients, a preliminary study

The current study aimed to investigate the diagnostic value of glycated albumin (GA), glycated hemoglobin (HbA1c), and a number of routine biomarkers as noninvasive indicators of liver fibrosis in patients with chronic hepatitis C (CHC). One hundred patients with CHC were subjected to full medical history and examination, in addition to ultrasound-guided liver biopsy and histopathological examination for assessment of liver fibrosis stage. GA and HbA1c values, GA/HbA1c ratio, liver function tests, complete blood count, and alpha fetoprotein (AFP) were determined. A novel noninvasive index, dubbed Fibrosis Prediction Score (FPS), was selected for predicting significant liver fibrosis based on total bilirubin, glycated albumin, platelet count, age, and AFP. A validation study for FPS was applied on archival data which include 66 diabetics' patients. The FPS had area under the curve (AUC) of 0.92 for classification of patients with significant fibrosis with 81% sensitivity and 95% specificity. The AUCs of FPS in predicting advanced fibrosis and cirrhosis were 0.86 and 0.82, respectively. Comparison of AST-to-platelet ratio index (APRI) and FIB-4 with FPS indicated increased sensitivity and specificity of FPS over APRI and FIB4 in both significant and advanced fibrosis. FPS has a good sensitivity and specificity for prediction of significant and advanced liver fibrosis in patients with CHC.

Agreement Between 2-Dimensional Shear Wave and Transient Elastography Values for Diagnosis of Advanced Chronic Liver Disease

BACKGROUND & AIMS

Inter-platform variation in liver stiffness evaluation (LSE) could hinder dissemination and clinical implementation of new ultrasound methods. We aimed to determine whether measurements of liver stiffness by bi-dimensional shear wave elastography (2D-SWE) with a Supersonic Imagine apparatus are comparable to those made by vibration-controlled transient elastography (VCTE).

METHODS

We collected data from 1219 consecutive patients with chronic liver disease who underwent LSE by VCTE and 2D-SWE (performed by blinded operators), on the same day, at a single center in France from September 2011 through June 2019. We assessed the ability of liver stiffness value distributions and 2D-SWE performances to identify patients with compensated advanced chronic liver disease (cACLD) according to the Baveno VI criteria, based on VCTE cut-off values.

RESULTS

VCTE and 2D-SWE values correlated (Pearson's correlation coefficient, 0.882; P < .0001; Lin concordance coefficient, 0.846; P < .0001). The median stiffness values were 6.7 kPa with VCTE (interquartile range, 4.8-11.6 kPa) and 7.1 kPa with 2D-SWE (interquartile range, 5.4-11.1 kPa) (P = .736). 2D-SWE values were slightly higher in the low percentiles and lower in the high percentiles; the best match with VCTE values were at approximately 7-9 kPa. The area under the curve of 2D-SWE for identifying of VCTE values below 10 was 0.964 (95% CI, 0.952-0.976) and for VCTE values above 15 kPa was 0.976 (95% CI, 0.963-0.988), with Youden index-associated cut-off values of 9.5 and 13kPa and best accuracy cut-off values of 10 kPa and 14 kPa, respectively. A 2D-SWE cut-off value of 10 kPa detected VCTE values below 10k Pa with 92% sensitivity, 87% specificity, and 91% accuracy.

CONCLUSIONS

Measurement of liver stiffness by VCTE or 2D-SWE produces comparable results. 2D-SWE accurately identifies patients with cACLD according to the Baveno VI criteria based on VCTE cut-off values. A 10 kPa 2D-SWE cut-off value can be used to rule out cACLD.

The role of elastography in alcoholic liver disease: fibrosis staging and confounding factors, a review of the current literature

INTRODUCTION

Alcohol-related liver disease (ALD) was estimated to have a prevalence of 2% among the USA population. Since severe fibrosis in compensated patients is the main predictor of long-term survival, it is of utmost importance to early detect patients with severe fibrosis before decompensation occurs. Liver elastography has been used to stage liver fibrosis. However, there is a widespread lack in guidelines for the correct use of liver stiffness (LS) in ALD.

EVIDENCE ACQUISITION

A structured search was carried out on MEDLINE/PubMed database. From the original 225 research articles identified, only 12 studies met the inclusion criteria, with 10 studies being eventually included.

EVIDENCE SYNTHESIS

According to reported data, patients with aspartate aminotransferase (AST)>100 IU/L and 50 IU/L showed significantly higher values of LS if compared to patients with the same fibrosis stage. Also, excessive alcohol consumption greatly influences elastography, leading to false fibrosis staging. When LS values >5-6 kPa are detected, several aspects should be taken into account. First of all, the patient should be asked about the current alcohol consumption (i.e. active vs. abstinence, determination of abstinence period, and quantification of alcohol intake), and if the patient is an active drinker, liver elastography can be repeated after a complete abstinence period of at least two weeks. and if the patient is an active drinker, liver elastography can be repeated after a complete abstinence period of at least two weeks. Secondly, clinicians should check liver transaminases level, and if AST are above 100 IU/L, they should be aware of a possible overestimation of fibrosis. However, whether transaminases-adapted cut-off values should be used for ad-hoc decisions in patients with no time or option to withdraw from alcohol consumption is still a matter of debate.

CONCLUSIONS

We hope that our review article may serve as a reference point in the prospect of futures guidelines.

The Performance of a 2-Dimensional Shear-Wave Elastography Technique for Predicting Different Stages of Liver Fibrosis Using Transient Elastography as the Control Method

The aim was to evaluate the performance of 2-dimensional (2D) shear-wave elastography from general electric (2D SWE-GE), implemented on the new LOGIQ S8 system, for the noninvasive assessment of liver fibrosis, and to identify liver stiffness (LS) cutoff values for predicting different stages of fibrosis using transient elastography (TE) as the control method. We included 179 consecutive subjects, with or without chronic hepatopathies, in whom LS was evaluated in the same session using 2 elastographic techniques: TE (FibroScan, EchoSens) and 2D SWE-GE (LOGIQ S8; GE Healthcare, Chalfont St Giles, United Kingdom). Reliable LS measurements were defined for TE: the median value of 10 measurements with a success rate of 60% or greater and an interquartile range/median ratio (IQR/M) < 0.30; for 2D SWE-GE: the median value of 10 measurements acquired in a homogenous area and IQR/M < 0.30. To discriminate between fibrosis stages by TE, we used the following cutoffs: F2-7; F3-9.5 and F4-12 kPa. Reliable LS measurements were obtained in 97.2% subjects by 2D SWE-GE and in 98.3% by TE (P = 0.72), so that 171 subjects were included for the final analysis. A good correlation was found between the LS values obtained by the 2 methods (r = 0.72, P < 0.0001). The best 2D SWE-GE cutoff value for F ≥ 2 was 6.9 kPa (areas under receiver operating characteristic [AUROC], 0.93; sensitivity, 85.8%; specificity, 90.2%), for F of 3 or greater, it was 8.2 kPa (AUROC, 0.93; sensitivity, 87.5%; specificity, 86.8%) and for F value of 4, it was 9.3 kPa (AUROC, 0.91; sensitivity, 85.7%; specificity, 81.2%). In conclusion, the best 2D SWE-GE (S8) cutoff values for predicting F2, F ≥ 3 and F = 4 were 6.9, 8.2, and 9.3 kPa.

Diagnostic Performance of Ultrasound Elastography and Serologic Fibrosis Indices for Evaluation of Hepatic Involvement in Wilson Disease

OBJECTIVES

To investigate the diagnostic value of transient elastography (TE), 2-dimensional (2D) shear wave elastography (SWE), and the serologic fibrosis indices aspartate transaminase-to-platelet ratio index (APRI) and Fibrosis-4 (FIB-4) score for Wilson disease (WD).

METHODS

We retrospectively identified patients with a diagnosis of WD who underwent TE and 2D SWE on the same day. Their APRI and FIB-4 scores were calculated. Hepatic involvement was classified into 5 clinical categories (I-V) based on the laboratory findings, hepatic morphologic characteristics on ultrasound (US) imaging, and clinical symptoms of cirrhosis: I, normal (n = 17); II, only biochemical abnormality (n = 15); III, altered hepatic morphologic characteristics (n = 10); IV, compensated liver cirrhosis (n = 3); and V, decompensated liver cirrhosis (n = 0). We compared the area under the receiver operating characteristic curve (AUROC) data for TE, 2D SWE, the APRI, and the FIB-4 score. A combined assessment of the serologic markers and US elastography was performed, and the AUROCs of the combinations were compared.

RESULTS

Forty-five patients were included in the study (median age, 16.0 years; range, 3-35 years). Transient elastography, 2D SWE, and APRI were comparable in distinguishing the clinical categories (AUROC, 0.799-0.928). The FIB-4 score showed lower diagnostic value in distinguishing clinical category I from the other categories (AUROC, 0.647). Combining the serologic markers and US elastography significantly increased the AUROC value of the FIB-4 score (with TE and 2D SWE, P = .01 and .02).

CONCLUSIONS

Transient elastography and 2D SWE showed excellent diagnostic accuracy for differentiating the clinical categories of hepatic involvement. The APRI showed better diagnostic performance than the FIB-4 score. The assessment of hepatic manifestations in WD can be improved by combining US elastography with serologic indices.

Ultrasound-based liver elastography: current results and future perspectives

Chronic liver disease affects 185 million population worldwide. It encompasses a heterogenous disease spectrum, but all can lead to the development of liver fibrosis. The degree of liver fibrosis is not only a prognosticator, but has also been used to guide the treatment strategy and to evaluate treatment response. Traditionally, staging of liver fibrosis is determined on histological analysis using samples obtained from an invasive liver biopsy. Ultrasound-based liver elastography is a non-invasive method of assessing diffuse liver disease in patients with known chronic liver disease. The use of liver elastography has led to a significant reduction in the number of liver biopsies performed to assess the severity of liver fibrosis and a liver biopsy is now reserved for only select sub-groups of patients. The aim of this review article is to discuss the key findings and current evidence for ultrasound-based elastography in diffuse liver disease as well as the technical challenges and to evaluate the potential research direction.

Shear wave elastography may be sensitive and more precise than transient elastography in predicting significant fibrosis

BACKGROUND

Noninvasive measurements including transient elastography (TE) and two-dimensional shear wave elastography (SWE) have been used clinically instead of liver biopsy for regular assessment of liver fibrosis in chronic hepatitis B (CHB) patients.

AIM

To investigate the diagnostic efficiency of SWE compared to TE by assessing independent influencing factors and performance for diagnosing significant fibrosis based on our cohort of treatment-naive CHB patients.

METHODS

Fifty-four treatment-naive CHB patients who underwent liver biopsy to determine whether to initiate antiviral therapy were enrolled. SWE, TE, serum tests and liver biopsy were performed for all participants. The fibrosis-4 and aspartate aminotransferase to platelet ratio index scores were also calculated. Potential independent influencing factors on SWE and TE values were analyzed. Based on liver pathology results, the agreement and correlation were determined, and a comparison of the two methods was performed.

RESULTS

There were 27 cases (50%) of mild fibrosis (F0-F2) and 27 (50%) cases of significant fibrosis (F3-F6); fibrosis was assessed with the Ishak scoring system. Multivariate linear regression analyses revealed that the fibrosis stage was the only factor that affected the SWE values (P < 0.001), whereas the total bilirubin level (P = 0.013) and fibrosis stage (P = 0.037) were independent factors that affected TE values. Orthogonal partial least squares discriminant analysis showed that the number of independent factors (VIP > 1) was higher for TE than SWE. Bland-Altman analysis showed satisfactory agreement between liver stiffness measurements (LSMs) of SWE and TE. Both SWE and TE could significantly discriminate significant fibrosis from mild fibrosis (P < 0.001). SWE exhibited a higher correlation with LSMs of liver fibrosis than TE (r = 0.65 and 0.50, P < 0.001). The diagnostic performance of SWE was better than that of TE for significant fibrosis (F > 2). The areas under the receiver operating characteristic curves of SWE and TE were 0.786 and 0.714, respectively. The optimal LSM cutoff values of SWE and TE were 9.05 kPa and 8.15 kPa, respectively.

CONCLUSION

Compared to the TE value, the SWE value was less affected by other factors. SWE may be more sensitive and precise than TE in predicting significant fibrosis (> F2) in CHB patients.

Benefits of prolonged-release pirfenidone plus standard of care treatment in patients with advanced liver fibrosis: PROMETEO study

BACKGROUND AND AIMS

Pirfenidone (PFD), an oral antifibrotic drug, has been authorized by the EMA and FDA for treatment of idiopathic pulmonary fibrosis. Few studies have addressed its use in advanced liver fibrosis (ALF). We evaluated a prolonged-release formulation (PR-PFD) plus standard of care on disease progression in ALF.

METHODS

281 ALF patients from 12 centers receiving PR-PFD (600 mg bid) were screened; 122 completed 1 year of treatment. Additionally, 74 patients received only standard of care regimen. Average age was 64 ± 12 years, 58% female. 43.5% had fatty liver disease (NAFLD), 22.5% viral hepatitis C (VHC), 17% autoimmune hepatitis (AIH), and 17% alcoholic liver disease (ALD). Baseline fibrosis was F4 in 74% and F3 in 26%. Antifibrotic effects were assessed by transient elastography (Fibroscan®) and Fibro Test® (FT); Cytokines and PFD plasma levels were tracked and quality of life evaluated.

RESULTS

We found a significant reduction in fibrosis in 35% of PR-PFD patients and only in 4.1% in non PR-PFD patients. Child-Pugh score improved in 29.7%. Biochemical values remained stable; 40.6% and 43.3% decreased ALT or AST, respectively. TGFβ1 (pg/mL) levels were lower in PFD-treated patients. PFD serum concentration (µg/mL) was higher (8.2 ± 1.7) in fibrosis regression profile (FRP) patients compared to fibrosis progression profile (FPP) patients (4.7 ± 0.3 µg/mL, p < 0.01). 12% reported transient burning or nausea and 7% photosensitivity. Quality of life (Euro-Qol scale) improved from 62 ± 5 to 84 ± 3 (p < 0.001) and from 32 ± 3 to 42 ± 2 (p < 0.008) (FACIT scale).

CONCLUSIONS

PR-PFD is efficacious and safe in ALF and associated with promising antifibrotic effects.

TRIAL REGISTRATION

Clinical trial number: NCT04099407.

2-D Ultrasound Shear Wave Elastography With Multi-Sphere-Source External Mechanical Vibration: Preliminary Phantom Results

Ultrasound shear wave elastography (SWE) imaging is emerging as a quantitative and non-invasive tissue characterization modality. Shear wave generation using external mechanical vibration (EMV) has received extensive research interest over acoustic radiation force impulse (ARFI) because of its low cost and potential for portability. In this paper, we propose an EMV concept with multiple spherical sources that can be easily reconfigured in three configurations to induce unique shear wave propagation patterns. We introduce two design embodiments of this concept bench test design for proof of concept and a clinically deployable design. The latter is designed to incorporate size, ergonomics, portability and power consumption considerations and constraints. Experimental validation on elasticity phantoms using both EMV designs demonstrates shear wave generation and elasticity reconstruction comparable in performance to ElastQ, a commercial ARFI-based shear elastography technology from Philips. In addition, the local displacement amplitude induced by EMV is 10 times greater than that induced by ARFI at the same given depth. Finally, the multiple configurations of the presented EMV design would allow exploration of advanced elastography methods such as tissue anisotropic elasticity.

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

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

Liver Stiffness Measurement With FibroScan: Use the Right Probe in the Right Conditions!

FibroScan's M and XL probes give significantly different results, which could lead to misevaluation of liver fibrosis if the correct probe is not chosen. According to the manufacturer, the M probe should be used when the skin–liver capsule distance (SCD) is <25 mm, and the XL probe should be used when SCD is ≥25 mm. We aimed at validating this recommendation and defining the conditions of use for FibroScan probes in clinical practice.

Liver Elastography in Primary Sclerosing Cholangitis Patients Using Three Different Scanner Systems

The aim of the study described here was to characterize three different liver elastography methods in primary sclerosing cholangitis (PSC) patients, for the first time exploring 2-D shear wave elastography (2-D-SWE) in PSC patients and its putative advantages over point shear wave elastography (pSWE). Sixty-six adult PSC patients (51 males, 77%) underwent liver elastography: Transient elastography (TE), pSWE and 2-D-SWE were applied head-to-head after B-mode ultrasonography and blood tests. Liver stiffness measurements (LSMs) by pSWE yielded lower values than those by TE; 2-D-SWE had less steep slope but was overall not significantly different from TE. Correlation between LSMs by pSWE and TE was excellent (intraclass correlation coefficient = 0.92); correlation for 2-D-SWE with either pSWE or TE was moderate but improved with exclusion of overweight individuals. LSMs correlated with the Enhanced Liver Fibrosis test (ELF) across all scanner systems. Our study indicates that LSM by different systems is feasible in PSC patients and that 2-D-SWE tends to underestimate stiffness compared with TE.

Noninvasive assessment of liver fibrosis in chronic hepatitis B carriers with sound touch elastography: study of surgical pathology specimens

PURPOSE

To evaluate the diagnostic performance of sound touch elastography (STE) for staging liver fibrosis in chronic hepatitis B (CHB) patients using pathological stage of surgical specimens as the reference standard.

METHOD

239 CHB patients were included. Liver stiffness measurements (LSMs) on STE and Supersonic shear imaging (SSI), gamma glutamyl transferase-to-platelet ratio (GPR), aspartate aminotransferase-to-platelet ratio index (APRI) and four-factor Fibrosis-4 (FIB-4) index were obtained. Areas under the receiver operating characteristic (ROC) curves (AUCs) for the diagnosis of fibrosis stage were calculated and compared.

RESULTS

The LSMs obtained by STE and SSI significantly correlated with the fibrosis stages (r = 0.757; r = 0.758, respectively, both p < 0.001). No significant differences in AUCs were observed between STE and SSI in identifying fibrosis ≥stage 1 (0.92 vs. 0.94), ≥stage 2 (0.89 vs. 0.91), ≥stage 3 (0.90 vs. 0.91) or stage 4 (0.92 vs. 0.91). Both STE and SSI had significantly higher AUCs in identifying each fibrosis stage than the GPR (0.68, 0.77, 0.76 and 0.79), APRI (0.53, 0.66, 0.74 and 0.69) and FIB-4 (0.61, 0.77, 0.79 and 0.74).

CONCLUSIONS

STE is an efficient tool for assessing liver fibrosis in CHB patients, with performance comparable to that of SSI and superior to that of biomarkers.

Ultrasound 2020 - Diagnostics & Therapy: On the Way to Multimodal Ultrasound: Contrast-Enhanced Ultrasound (CEUS), Microvascular Doppler Techniques, Fusion Imaging, Sonoelastography, Interventional Sonography

BACKGROUND

 Ultrasound as a non-ionizing imaging procedure is one of the most important diagnostic procedures in everyday clinical practice. The technology is widely used. Due to constant technical innovations, sonographic procedures, such as contrast-enhanced ultrasound (CEUS), sonoelastography, new microvascular Doppler modalities and, as an example of interventional procedures, sonographically controlled microwave ablation (MWA), are becoming increasingly important in diagnostic imaging and interventional medicine alongside CT and MRI. However, this also requires greater expertise, specialization and qualification on the part of users.

METHOD

 This review article provides information about the range of technical innovations in ultrasound in recent years and describes the underlying technology, the clinical applications, and their diagnostic value. These are presented in the context of the current literature, explaining their advantages and disadvantages and their clinical value.

RESULTS AND CONCLUSION

 Contrast-enhanced ultrasound (CEUS), microvascular Doppler modalities, fusion imaging and elastography complement B-scan ultrasound and conventional Doppler procedures for various problems. Microwave ablation (MWA) has a firm place as an ablative procedure for local tumor therapy in different organ systems and can be performed under ultrasound guidance. Thanks to new developments, the possibilities of ultrasound are now greater than ever. Knowledge of the technology, indications, and possible applications of newer procedures is essential for adequate patient care.

KEY POINTS

  · Contrast-enhanced ultrasound (CEUS) allows an increase in sensitivity and specificity in the assessment of parenchymal lesions.. · CEUS allows the microperfusion to be visualized and quantified. For larger vessels, CEUS is an important instrument in diagnosing endoleak after stenting.. · Microvascular Doppler techniques with clutter suppression algorithms allow a more accurate representation of the smallest vessels than regular color or power Doppler.. · Elastography of the liver in diffuse hepatopathies is a noninvasive diagnostic tool to exclude higher grade fibrosis/cirrhosis.. · Microwave ablation (MWA) also offers sonographically controlled ablation of tumors..

CITATION FORMAT

· Kloth C, Kratzer W, Schmidberger J et al. Ultrasound 2020 - Diagnostics & Therapy: On the Way to Multimodal Ultrasound: Contrast-Enhanced Ultrasound (CEUS), Microvascular Doppler Techniques, Fusion Imaging, Sonoelastography, Interventional Sonography . Fortschr Röntgenstr 2021; 193: 23 - 32.

Advances in non-invasive assessment of hepatic fibrosis

Liver fibrosis should be assessed in all individuals with chronic liver disease as it predicts the risk of future liver-related morbidity and thus need for treatment, monitoring and surveillance. Non-invasive fibrosis tests (NITs) overcome many limitations of liver biopsy and are now routinely incorporated into specialist clinical practice. Simple serum-based tests (eg, Fibrosis Score 4, non-alcoholic fatty liver disease Fibrosis Score) consist of readily available biochemical surrogates and clinical risk factors for liver fibrosis (eg, age and sex). These have been extensively validated across a spectrum of chronic liver diseases, however, tend to be less accurate than more 'complex' serum tests, which incorporate direct measures of fibrogenesis or fibrolysis (eg, hyaluronic acid, N-terminal propeptide of type three collagen). Elastography methods quantify liver stiffness as a marker of fibrosis and are more accurate than simple serum NITs, however, suffer increasing rates of unreliability with increasing obesity. MR elastography appears more accurate than sonographic elastography and is not significantly impacted by obesity but is costly with limited availability. NITs are valuable for excluding advanced fibrosis or cirrhosis, however, are not sufficiently predictive when used in isolation. Combining serum and elastography techniques increases diagnostic accuracy and can be used as screening and confirmatory tests, respectively. Unfortunately, NITs have not yet been demonstrated to accurately reflect fibrosis change in response to treatment, limiting their role in disease monitoring. However, recent studies have demonstrated lipidomic, proteomic and gut microbiome profiles as well as microRNA signatures to be promising techniques for fibrosis assessment in the future.

Measurement of Liver Stiffness with 2D-Shear Wave Elastography (2D-SWE) in Bariatric Surgery Candidates Reveals Acceptable Diagnostic Yield Compared to Liver Biopsy

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is common among severely obese patients. Two-dimensional shear wave elastography (2D-SWE) has been validated as a noninvasive diagnostic tool for liver stiffness measurement. However, the technical feasibility and accuracy of this method in severely obese patients are still under debate.

OBJECTIVE

We aimed to assess the diagnostic accuracy of 2D-SWE in bariatric surgery candidates in comparison with the gold standard liver biopsy.

METHODS

Ninety severely obese candidates for bariatric surgery were included. Liver stiffness was measured using 2D-SWE 14 days before liver biopsy. Liver biopsy was taken on the day of surgery. The area under the receiver operating curve (AUROC) was calculated for the staging of liver fibrosis.

RESULTS

2D-SWE was performed in 97.3% of patients successfully. Histologic stages of fibrosis (F0-F4) were detected in 34.2%, 36%, 6.3%, 3.6%, and 0.9% of patients, respectively. The AUROC for 2D-SWE was 0.77 for F1, 0.72 for F2, 0.77 for F3, and 0.70 for F4. In univariate analysis, 2D-SWE values were correlated with BMI, waist circumference, NAFLD activity score (NAS), and steatosis, whereas these components did not affect liver stiffness in multivariate analysis.

CONCLUSION

Two-dimensional shear wave elastography of the liver can be feasible and has good accuracy in severely obese candidates for bariatric surgery. Therefore, 2D-SWE may be a good option for assessing liver fibrosis, especially in the early stages of fibrosis to lessen complications of surgery in this population. However, this method should be applied on a larger scale for late stage of fibrosis.

On the Challenges Associated with Obtaining Reproducible Measurements Using SWEI in the Median Nerve

This work discusses challenges we have encountered in acquiring reproducible measurements of shear wave speed (SWS) in the median nerve and suggests methods for improving reproducibility. First, procedural acquisition challenges are described, including nerve echogenicity, transducer pressure and transmit focal depth. Second, we present an iterative, radon sum-based algorithm that was developed specifically for measuring the SWS in median nerves. SWSs were measured using single track location shear wave elasticity imaging (SWEI) in the median nerves of six healthy volunteers and six patients diagnosed with carpal tunnel syndrome. Unsuccessful measurements were associated with several challenges including reverberation artifacts, low signal-to-noise ratio and temporal window limitations for tracking the velocity wave. To address these challenges, an iterative convergence algorithm was implemented to identify an appropriate temporal processing window that removed the reverberation artifacts while preserving shear wave signals. Algorithmically, it was important to consider the lateral regression kernel size and position and the temporal window. Procedurally, both nerve echogenicity and transducer compression were determined to impact the measured SWS. Shear waves were successfully measured in the median nerve proximal to the carpal tunnel, but SWEI measurements were significantly compromised within the carpal tunnel itself. The velocity-based SWSs were statistically significantly higher than the displacement SWSs (p < 0.0001), demonstrating for the first time dispersion in the median nerve in vivo using SWEI.

Why Are Viscosity and Nonlinearity Bound to Make an Impact in Clinical Elastographic Diagnosis?

The adoption of multiscale approaches by the biomechanical community has caused a major improvement in quality in the mechanical characterization of soft tissues. The recent developments in elastography techniques are enabling in vivo and non-invasive quantification of tissues' mechanical properties. Elastic changes in a tissue are associated with a broad spectrum of pathologies, which stems from the tissue microstructure, histology and biochemistry. This knowledge is combined with research evidence to provide a powerful diagnostic range of highly prevalent pathologies, from birth and labor disorders (prematurity, induction failures, etc.), to solid tumors (e.g., prostate, cervix, breast, melanoma) and liver fibrosis, just to name a few. This review aims to elucidate the potential of viscous and nonlinear elastic parameters as conceivable diagnostic mechanical biomarkers. First, by providing an insight into the classic role of soft tissue microstructure in linear elasticity; secondly, by understanding how viscosity and nonlinearity could enhance the current diagnosis in elastography; and finally, by compounding preliminary investigations of those elastography parameters within different technologies. In conclusion, evidence of the diagnostic capability of elastic parameters beyond linear stiffness is gaining momentum as a result of the technological and imaging developments in the field of biomechanics.

Risk stratification of patients with nonalcoholic fatty liver disease using a case identification pathway in primary care: a cross-sectional study

BACKGROUND

Identification of patients with nonalcoholic fatty liver disease (NAFLD) with advanced liver fibrosis in primary care remains an unmet need. Our primary objective was to implement a pathway driven by shear wave elastography (SWE) to facilitate risk stratification of patients with NAFLD within primary care and evaluate whether SWE assessment can reduce referrals of patients with NAFLD at low risk for fibrosis to hepatology.

METHODS

A multidisciplinary NAFLD clinical care pathway was codeveloped by hepatologists, radiologists and primary care physicians in Calgary to provide access to SWE-based screening of patients with NAFLD risk factors in primary care. The study outcome measures were estimated NAFLD-related referrals to the hepatology service in Calgary after implementation of the NAFLD pathway and characteristics of patients with NAFLD at risk for advanced fibrosis. The NAFLD pathway was implemented in January 2018 and was made available to all primary care physicians in the Calgary Health Zone. Patients with NAFLD who had liver stiffness (SWE value ≥ 8.0 kPa) or an inconclusive assessment were referred to hepatology. A serum liver fibrosis score was also measured with the fibrosis-4 (FIB-4) index, and performance of an FIB-4 index score of 1.30 or greater to risk stratify patients with NAFLD was evaluated. Demographic, clinical and laboratory characteristics of study groups were compared.

RESULTS

Between March and October 2018, 2084 patients with suspected NAFLD were evaluated. Nonalcoholic fatty liver disease was confirmed by ultrasonography in 1958 (94.1%). A majority of the cohort had elevated liver enzyme values (1028 [52.5%]) and obesity (body mass index ≥ 30) (1063/1764 [60.3%]). Most patients with NAFLD (1791 [91.5%]) had an SWE value less than 8.0 kPa and were not referred to hepatology. Sixty-seven patients (3.4%) had an SWE value of 8.0 kPa or more, and 100 (5.1%) had an inconclusive SWE; these patients were referred to hepatology. Using an FIB-4 index score cut-off of 1.30 would have led to hepatology referral of 396/1251 patients (31.6%).

INTERPRETATION

Implementation of a primary care-accessible SWE pathway for patients with NAFLD facilitated fibrosis risk stratification and greatly reduced hepatology referrals. Using the FIB-4 index score alone would led to higher rates of referral of patients with NAFLD.

Comparison of point and 2-dimensional shear wave elastography for the evaluation of liver fibrosis

PURPOSE

This study aimed to assess the technical performance of ElastQ Imaging compared with ElastPQ and to investigate the correlation between liver stiffness (LS) values obtained using these two techniques.

METHODS

This retrospective study included 249 patients who underwent LS measurements using both ElastPQ and ElastQ Imaging equipped on the same machine. The applicability, repeatability (coefficient of variation [CV]), acquisition time, and LS values were compared using the chi-square or Wilcoxon signed-rank tests. In the development group, the correlation between the LS values obtained by the two techniques was assessed with Spearman correlation coefficients and linear regression analysis. In the validation group, the agreement between the estimated and real LS values was evaluated using a Bland-Altman plot.

RESULTS

ElastQ Imaging had higher applicability (94.0% vs. 78.3%, P<0.001) and higher repeatability, with a lower median CV (0.127 vs. 0.164, P<0.001) than did ElastPQ. The median acquisition time of ElastQ Imaging was significantly shorter than that of ElastPQ (45.5 seconds vs. 96.5 seconds, P<0.001). The median LS value obtained using ElastQ Imaging was significantly higher than that obtained using ElastPQ (5.60 kPa vs. 5.23 kPa, P<0.001). The LS values between the two techniques exhibited a strong positive correlation (r=0.851, P<0.001) in the development group. The mean difference and 95% limits of agreement were 0.0 kPa (-3.9 to 3.9 kPa) in the validation group.

CONCLUSION

ElastQ Imaging may be more reliable and faster than ElastPQ, with strongly correlated LS measurements.

Viscoelastic Biomarkers of Ex Vivo Liver Samples via Torsional Wave Elastography

The clinical ultrasound community demands mechanisms to obtain the viscoelastic biomarkers of soft tissue in order to quantify the tissue condition and to be able to track its consistency. Torsional Wave Elastography (TWE) is an emerging technique proposed for interrogating soft tissue mechanical viscoelastic constants. Torsional waves are a particular configuration of shear waves, which propagate asymmetrically in-depth and are radially transmitted by a disc and received by a ring. This configuration is shown to be particularly efficient in minimizing spurious p-waves components and is sensitive to mechanical constants, especially in cylinder-shaped organs. The objective of this work was to validate (TWE) technique against Shear Wave Elasticity Imaging (SWEI) technique through the determination of shear wave velocity, shear moduli, and viscosity of ex vivo chicken liver samples and tissue mimicking hydrogel phantoms. The results of shear moduli for ex vivo liver tissue vary 1.69–4.0kPa using TWE technique and 1.32–4.48kPa using SWEI technique for a range of frequencies from 200 to 800Hz. Kelvin–Voigt viscoelastic parameters reported values of μ = 1.51kPa and η = 0.54Pa·s using TWE and μ = 1.02kPa and η = 0.63Pa·s using SWEI. Preliminary results show that the proposed technique successfully allows reconstructing shear wave velocity, shear moduli, and viscosity mechanical biomarkers from the propagated torsional wave, establishing a proof of principle and warranting further studies.

Ultrasound-based liver elastography in the assessment of fibrosis

Ultrasound-based elastography has rapidly replaced the need for liver biopsy in most patients with chronic liver disease in recent years. The technique is now widely supported by many manufacturers. This review will introduce various current ultrasound-based elastography techniques, review the physics and scanning techniques, discuss potential cofounding factors as well as summarising the evidence for its use in staging liver fibrosis using shear-wave elastography among different disease aetiologies. Future challenges and directions will be also be discussed.

Transfer learning radiomics based on multimodal ultrasound imaging for staging liver fibrosis

Objectives

To propose a transfer learning (TL) radiomics model that efficiently combines the information from gray scale and elastogram ultrasound images for accurate liver fibrosis grading.

Methods

Totally 466 patients undergoing partial hepatectomy were enrolled, including 401 with chronic hepatitis B and 65 without fibrosis pathologically. All patients received elastography and got liver stiffness measurement (LSM) 2–3 days before surgery. We proposed a deep convolutional neural network by TL to analyze images of gray scale modality (GM) and elastogram modality (EM). The TL process was used for liver fibrosis classification by Inception-V3 network which pretrained on ImageNet. The diagnostic performance of TL and non-TL was compared. The value of single modalities, including GM and EM alone, and multimodalities, including GM + LSM and GM + EM, was evaluated and compared with that of LSM and serological indexes. Receiver operating characteristic curve analysis was performed to calculate the optimal area under the curve (AUC) for classifying fibrosis of S4, ≥ S3, and ≥ S2.

Results

TL in GM and EM demonstrated higher diagnostic accuracy than non-TL, with significantly higher AUCs (all p < .01). Single-modal GM and EM both performed better than LSM and serum indexes (all p < .001). Multimodal GM + EM was the most accurate prediction model (AUCs are 0.950, 0.932, and 0.930 for classifying S4, ≥ S3, and ≥ S2, respectively) compared with GM + LSM, GM and EM alone, LSM, and biomarkers (all p < .05).

Conclusions

Liver fibrosis can be staged by a transfer learning modal based on the combination of gray scale and elastogram ultrasound images, with excellent performance.

Key Points

• Transfer learning consists in applying to a specific deep learning algorithm that pretrained on another relevant problem, expected to reduce the risk of overfitting due to insufficient medical images.

• Liver fibrosis can be staged by transfer learning radiomics with excellent performance.

• The most accurate prediction model of transfer learning by Inception-V3 network is the combination of gray scale and elastogram ultrasound images.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06595-w) contains supplementary material, which is available to authorized users.

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.

The assessment of liver fibrosis in children with obesity on two methods: transient and two dimensional shear wave elastography

The aim of this study was to assess the liver stiffness values in children with obesity versus healthy children on 2D-SWE and TE taking into account different laboratory parameters. We performed a case-control study on 287 children aged between 3 to 18 years, admitted in a Romanian Pediatric Tertiary Hospital, which we divided according to the body mass index (BMI) into two groups: the study group-77 children with obesity, and control group-210 children with normal weight. All children underwent anamnesis, clinical exam, laboratory parameters, ultrasound exam, and elastography. Children with obesity presented higher values of platelets, AST, ALT, and AAR as compared to control group (p = 0.0005/p = 0.0065/p < 0.0001/p < 0.0001). We found no significant differences for APRI between the two groups (p = 0.9827), although the values were higher in children with obesity. Significantly higher values of liver stiffness in children with obesity on both 2D-SWE and TE (p = 0.0314/p < 0.0001) were obtained. Similarly, the velocity values measured by 2D-SWE were also significantly higher in the study group (p < 0.0001). Our findings revealed significantly higher levels of platelets, transaminases, AAR, and liver stiffness values on both TE and 2D-SWE in children with obesity. 2D-SWE and TE might represent useful non-invasive methods for predicting liver impairment associated to pediatric obesity.

Metabolic Syndrome Is Associated With Advanced Liver Fibrosis Among Pediatric Patients With Non-alcoholic Fatty Liver Disease

Background: Non-alcoholic fatty liver disease (NAFLD) among children is a growing concern with potential significant outcome. This study aims to investigate the relationship between hepatic steatosis, metabolic syndrome, and liver fibrosis among children with obesity and diabetes mellitus. Methodology: Children aged 6-18 years old were recruited from pediatric obesity and diabetes clinic in University Malaya Medical Center (UMMC) between year 2016 and 2019. Data on basic demographics, anthropometric measurements and clinical components of metabolic syndrome were collected. Transient elastography was performed with hepatic steatosis and liver fibrosis assessed by controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) respectively. Mild, moderate and severe steatosis were defined as >248, >268, and >280 dB/m respectively, and LSM above 7.0 kPa for fibrosis stage F ≥ 2, 8.7 kPa for F ≥ 3, and 10.3 kPa for F4 (cirrhosis). Results: A total of 57 children (60% male) with median age of 13 years old were recruited. Fifty (87.7%) of the children are obese and 27 (54%) out of 50 are morbidly obese. Among 44 (77.2%) patients with steatosis, 40 (70.2%) had severe steatosis and 18 (40.9%) had developed liver fibrosis of stage 2 and above. Advanced fibrosis or cirrhosis was detected in 8 (18.2%) children with presence of steatosis. Twenty-three out of 57 (40.4%) was diagnosed with metabolic syndrome. Fibrosis is three times more likely to occur in the presence of metabolic syndrome (OR = 3.545, 95% CI: 1.135-11.075, p = 0.026). Waist circumference is a significant predictor of fibrosis after multiple regression analysis. Conclusion: Obese children with metabolic syndrome are more likely to have advanced liver fibrosis compared to those without metabolic syndrome. Waist circumference predicts development of liver fibrosis.

2D shear wave elastography: measurement acquisition and reliability criteria in noninvasive assessment of liver fibrosis

PURPOSE

The objective was to evaluate the accuracy of 2D shear wave elastography (SWE) in predicting stages of liver fibrosis using five individual versus grouped measurements and different reliability criteria.

MATERIALS AND METHODS

This is a prospective study of 109 patients who underwent hepatic 2D SWE (Canon Aplio 500) prior to liver biopsy for varied indications. Liver fibrosis was staged using the METAVIR scoring system (F = 0-4). Propagation mapping was used to guide ten SWE measurements from the liver parenchyma: five individual measurements and five grouped measurements. IQR/median, SD/median, and SD/mean were examined as quality criteria for patient inclusion at various thresholds (IQR/median ≤ 0.15, 0.2, 0.3, 0.4, 0.5; SD/median ≤ 0.15, 0.2, 0.3; SD/mean ≤ 0.2, 0.3, 0.5). Threshold for clinically significant fibrosis (F ≥ 2) was determined with receiver operating characteristic (ROC) analysis.

RESULTS

There was high agreement between individual and grouped measurements without statistically significant differences (intraclass correlation coefficient = 0.82; p = 0.26-0.96). When no quality criterion was used (n = 103), the optimal threshold was 11.3 kPa [AUROC 0.78, 95% CI (0.69, 0.88)] with sensitivity and specificity of 80% and 66%, respectively. All quality criteria were associated with equal or higher AUROC ranging from 0.78 to 0.87. IQR/median ≤ 0.5 (n = 88) achieved the highest sensitivity of 85% and only excluded a small subset of patients. The AUROC and specificity were 0.83 [95% CI (0.74, 0.92)] and 72%, respectively.

SIGNIFICANCE

Quality criterion IQR/median ≤ 0.5 increases sensitivity and specificity in prediction of clinically significant liver fibrosis while excluding only a small subset of patients. Grouped measurements are comparable to individual measurements and may help increase procedural efficiency.

Inter-platform reproducibility of liver stiffness measured with two different point shear wave elastography techniques and 2-dimensional shear wave elastography using the comb-push technique

PURPOSE

The purpose of this study was to compare the technical success rate and reliability of measurements made using three shear wave elastography (SWE) techniques and to assess the inter-platform reproducibility of the resultant liver stiffness measurements.

METHODS

This prospective study included 54 patients with liver disease. Liver stiffness (LS) measurements were obtained using 2-point SWE techniques (Virtual Touch Quantification and S-Shearwave) and 2-dimensional (2D) SWE, with transient elastography (TE) serving as the reference standard. The technical success rates and measurement reliability of the three techniques were compared. LS values measured using the three SWE techniques and TE were compared using Spearman correlation coefficients and 95% Bland-Altman limits of agreement. Intra-class correlation coefficients (ICC) were used to analyze the inter-platform reproducibility of LS measurements.

RESULTS

The three SWE techniques and TE showed similar technical success rates (P=0.682) but demonstrated significant differences in the reliability of LS measurements (P=0.006) and mean LS measurements (P<0.001). Despite strong correlations (r=0.73-0.94) between SWE systems, various degrees of inter-platform reproducibility (ICC, 0.58-0.92) were observed for the three SWE techniques. The best agreement was observed between S-Shearwave and TE (ICC, 0.92), and the worst agreement was observed between 2D-SWE and TE (ICC, 0.58). In the BlandAltman analysis, a tendency toward lower LS values with the three SWE techniques than with TE in patients with F3 and F4 disease was observed.

CONCLUSION

Significant inter-system variability was observed in LS measurements made using the three SWE techniques. Therefore, LS values measured using different SWE techniques should not be used interchangeably for longitudinal follow-up.

[Role of the radiologist in surgery of colorectal liver metastases : What should be removed and what must remain]

BACKGROUND

The radical resection of colorectal liver metastases is the only curative option for affected patients. If properly performed, surgery provides the chance of long-term tumor-free survival.

OBJECTIVE

Summary of the critical interaction points between radiology and surgery in the planning and performance of (complex) liver resections.

RESULTS

There are many interaction points between radiology and surgery in the treatment of patients with colorectal liver metastases. Radiology supports surgery by providing detailed information of the localization of metastases, information on liver inflow and outflow as well as basic information on liver quality and function. Perioperatively, it provides interventional treatment options for postoperative complications as well as ablation of non-resectable metastases.

CONCLUSION

Complex liver resections can only be performed properly and successfully after thorough planning by an interdisciplinary board of surgeons, radiologists and associated disciplines.

Prospective comparison of 2D-shearwave elastography in both liver lobes in healthy subjects and in patients with chronic liver disease

Background/aims: 2D-shearwave elastography is an established method for liver stiffness measurement (LSM). However, the success rate of LSM using the recommended standard technique in the right lobe is limited by several factors. We aimed to compare LSM in the right and left liver lobe in order to evaluate whether LSM in the left lobe could be an alternative if measurements in the right lobe are not feasible. Methods: A total of 116 subjects, 58 healthy volunteers and 58 patients with chronic liver disease (CLD), were prospectively included. LSM were performed in the right lobe and in the left lobe, both in neutral and in inspiration position. Results: LSM in the left lobe (8.39(±4.83)kPa) was significantly (p < .001) higher than LSM in the right lobe (6.27(±2.45)kPa). LSM in inspiration position (8.60(±4.33) kPa) was significantly (p = .009) higher than LSM in neutral position (7.70(±3.01)kPa). LSM in the left lobe overestimated the grade of fibrosis in 50.0% of the patients with CLD. However, correlation between LSM values right and left was strong (r = 0.856) and additional use of LSM in the left lobe increased the success rate from 106/116 (91.4%) to 112/116 (96.6%; p = .098). High skin-to-liver-capsule-distance and presence of ascites were independent risk factors for non-successful LSM. Conclusions: Despite significantly higher values, LSM in the left lobe may be an alternative if LSM in the right lobe is not feasible, and cirrhosis can be ruled out with high probability if LSM is within the normal range.

Value of Real-Time Shear Wave Elastography Versus Acoustic Radiation Force Impulse Imaging in the Diagnosis of Female Bladder Neck Obstruction

OBJECTIVE

To investigate the application value of shear wave elastography (SWE) and acoustic radiation force impulse imaging (ARFI) in the diagnosis of female bladder neck obstruction (FBNO), we compared the advantages of these 2 methods to provide a more accurate reference for clinical work.

METHODS

From April 2016 to February 2018, 27 patients who were diagnosed with FBNO by cystoscopy and/or urine dynamics testing were selected for the study, together with 24 healthy adults in a case-control study at Liaoning Province People's Hospital. We collected general information from 27 patients with FBNO, and using transperineal 2-dimensional ultrasound detection, shear wave elastography (SWE) and ARFI were used, respectively, to detect the Young's modulus and shear wave velocity (SWV) of the bladder necks. Cystoscopy results were considered to be the gold standard, and receiver operating characteristic (ROC) curves were drawn for ARFI, SWE, and the combined diagnosis of the two. The efficacy of the diagnosis was determined by comparing the areas under the ROC curves and calculating the sensitivity, specificity, and accuracy.

RESULTS

The areas under the ROC curve for the Q-box mean and max value detected by SWE for FBNO patients were 88.4% and 89.9%, respectively, and the sensitivity, specificity, and accuracy were 81.5%, 79.2%, and 80.4%, respectively. The area under the ROC curve detected by ARFI for FBNO patients was 93.7%, and the sensitivity, specificity, and accuracy were 88.9%, 79.2%, and 84.3%, respectively. The sensitivity, specificity, and accuracy of the combined detection of ARFI and SWE were 92.5%, 87.5%, and 90.2%, respectively. The best diagnostic cutoff point of the SWV or the Q-box mean and max value of SWE in FBNO obtained with the ROC curve was SWV = 2.38 m/s (sensitivity, 71.4%; specificity, 82.5%), Q-box mean = 20.2 kPa, Q-box max = 39.8 kPa (sensitivity, 67.5%; specificity, 76.2%). The average shear wave velocity of ARFI, Q-box mean, and Q-box max value of SWE in the control group were 1.89 ± 0.35 m/s, 15.3 ± 3.6 kPa, and 29.2 ± 8.7 kPa, respectively. In the FBNO group, these values were 2.81 ± 0.63) m/s, 27.2 ± 8.6 kPa, and 51.2 ± 12.3 kPa, respectively. The differences were statistically significant (P < .05).

CONCLUSION

The value of the ARFI in the diagnosis of FBNO is a little greater than that of SWE in terms of sensitivity and accuracy, and the combined detection of ARFI and SWE performs better than ARFI or SWE employed separately.

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.

The remarkable history of the hepatitis C virus

The infection with the hepatitis C virus (HCV) is an example of the translational research success. The reciprocal interactions between clinicians and scientists have allowed in 30 years the initiation of empirical treatments by interferon, the discovery of the virus, the development of serological and virological tools for diagnosis but also for prognosis (the non-invasive biochemical or morphological fibrosis tests, the predictors of the specific immune response including genetic IL28B polymorphisms). Finally, well-tolerated and effective treatments with oral antivirals inhibiting HCV non-structural viral proteins involved in viral replication have been marketed this last decade, allowing the cure of all infected subjects. HCV chronic infection, which is a public health issue, is a hepatic disease which may lead to a cirrhosis and an hepatocellular carcinoma (HCC) but also a systemic disease with extra-hepatic manifestations either associated with a cryoglobulinemic vasculitis or chronic inflammation. The HCV infection is the only chronic viral infection which may be cured: the so-called sustained virologic response, defined by undetectable HCV RNA 12 weeks after the end of the treatment, significantly reduces the risk of morbidity and mortality associated with hepatic and extra-hepatic manifestations which are mainly reversible. The history of HCV ends with the pangenotypic efficacy of the multiple combinations, easy to use for 8-12 weeks with one to three pills per day and little problems of tolerance. This explains the short 30 years from the virus discovery to the viral hepatitis elimination policy proposed by the World Health Organization (WHO) in 2016.

Comparison of liver stiffness assessment by transient elastography and shear wave elastography using six ultrasound devices

AIM

Transient elastography (TE) is the gold standard for measurement of liver stiffness. The usefulness of shear wave elastographies (SWE) is well accepted. However, the measurement values cannot be equivalently compared because cut-off values for the diagnosis of liver fibrosis are different among those devices. We aimed to clarify correlations, to generate the regression equations between TE and SWEs, and to compare the diagnostic ability of each device to diagnose liver fibrosis.

METHODS

A total of 109 patients with chronic liver disease who underwent liver biopsy and same-day evaluation of liver stiffness using six ultrasound devices were analyzed. The diagnostic ability of liver stiffness from each ultrasound device and correlations between TE and each SWE were analyzed.

RESULTS

Liver stiffness measured by all six ultrasound devices increased significantly as liver fibrosis stage advanced (P < 0.001). Receiver operating characteristic (ROC) curve analysis for predicting significant fibrosis (≥F2) and cirrhosis yielded area under the ROC curve (AUROC) values based on TE of 0.830 (95% confidence interval [CI], 0.755-0.905) and 0.959 (95% CI, 0.924-0.995), respectively. The AUROCs for predicting significant fibrosis (≥F2) and cirrhosis (F4) based on SWE from all five ultrasound devices were over 0.8 and 0.9, respectively. Furthermore, the correlation coefficients between TE values and SWE values from five ultrasound devices were all over 0.8, indicating a strong relationship.

CONCLUSION

Our study showed strong correlations between TE and SWEs with high correlation coefficients. The regression equations between TE and SWEs demonstrated the ability to compare the measurement values in each device equivalently.

Diagnostic value of two dimensional shear wave elastography combined with texture analysis in early liver fibrosis

BACKGROUND

Staging diagnosis of liver fibrosis is a prerequisite for timely diagnosis and therapy in patients with chronic hepatitis B. In recent years, ultrasound elastography has become an important method for clinical noninvasive assessment of liver fibrosis stage, but its diagnostic value for early liver fibrosis still needs to be further improved. In this study, the texture analysis was carried out on the basis of two dimensional shear wave elastography (2D-SWE), and the feasibility of 2D-SWE plus texture analysis in the diagnosis of early liver fibrosis was discussed.

AIM

To assess the diagnostic value of 2D-SWE combined with textural analysis in liver fibrosis staging.

METHODS

This study recruited 46 patients with chronic hepatitis B. Patients underwent 2D-SWE and texture analysis; Young's modulus values and textural patterns were obtained, respectively. Textural pattern was analyzed with regard to contrast, correlation, angular second moment (ASM), and homogeneity. Pathological results of biopsy specimens were the gold standard; comparison and assessment of the diagnosis efficiency were conducted for 2D-SWE, texture analysis and their combination.

RESULTS

2D-SWE displayed diagnosis efficiency in early fibrosis, significant fibrosis, severe fibrosis, and early cirrhosis (AUC > 0.7, P < 0.05) with respective AUC values of 0.823 (0.678-0.921), 0.808 (0.662-0.911), 0.920 (0.798-0.980), and 0.855 (0.716-0.943). Contrast and homogeneity displayed independent diagnosis efficiency in liver fibrosis stage (AUC > 0.7, P < 0.05), whereas correlation and ASM showed limited values. AUC of contrast and homogeneity were respectively 0.906 (0.779-0.973), 0.835 (0.693-0.930), 0.807 (0.660-0.910) and 0.925 (0.805-0.983), 0.789 (0.639-0.897), 0.736 (0.582-0.858), 0.705 (0.549-0.883) and 0.798 (0.650-0.904) in four liver fibrosis stages, which exhibited equivalence to 2D-SWE in diagnostic efficiency (P > 0.05). Combined diagnosis (PRE) displayed diagnostic efficiency (AUC > 0.7, P < 0.01) for all fibrosis stages with respective AUC of 0.952 (0.841-0.994), 0.896 (0.766-0.967), 0.978 (0.881-0.999), 0.947 (0.835-0.992). The combined diagnosis showed higher diagnosis efficiency over 2D-SWE in early liver fibrosis (P < 0.05), whereas no significant differences were observed in other comparisons (P > 0.05).

CONCLUSION

Texture analysis was capable of diagnosing liver fibrosis stage, combined diagnosis had obvious advantages in early liver fibrosis, liver fibrosis stage might be related to the hepatic tissue hardness distribution.