Diagnostic problems in two-dimensional shear wave elastography of the liver

Two-dimensional shear wave elastography (2D-SWE) is used in the clinical setting for observation of the liver. Unfortunately, a wide spectrum of artifactual images are frequently encountered in 2D-SWE, the precise mechanisms of which remain incompletely understood. This review was designed to present many of the artifactual images seen in 2D-SWE of the liver and to analyze them by computer simulation models that support clinical observations. Our computer simulations yielded the following suggestions: (1) When performing 2D-SWE in patients with chronic hepatic disease, especially liver cirrhosis, it is recommended to measure shear wave values through the least irregular hepatic surface; (2) The most useful 2D-SWE in patients with focal lesion will detect lesions that are poorly visible on B-mode ultrasound and will differentiate true tumors from pseudo-tumors (e.g., irregular fatty change); and (3) Measurement of shear wave values in the area posterior to a focal lesion must be avoided.     

肝脏实时剪切波弹性成像和超声量化评分评价恩替卡韦治疗慢性乙型肝炎肝纤维化疗效的研究

目的 评价恩替卡韦治疗慢性乙型肝炎肝纤维化的疗效,并使用肝脏实时剪切波弹性成像和超声量化评分对疗效进行对比分析.方法 选择在2017年10月至2018年3月本院收治的54例慢性乙型肝炎肝纤维化患者,对其进行肝脏实时剪切波弹性成像和超声量化检查,之后对患者实施恩替卡韦治疗,治疗周期为1年,治疗后再次实施肝脏实时剪切波弹性...     

Magnetic resonance elastography for the detection and staging of liver fibrosis in chronic hepatitis B

Objectives

We measured the accuracy of magnetic resonance elastography (MRE) for the detection and staging of liver fibrosis in chronic hepatitis B (CHB) and compared it with serum fibrosis markers.

Methods

Prospective comparison of MRE and routine serum fibrosis markers, namely serum alanine aminotransferase (ALT), serum aspartate aminotransferase (AST), ALT/AST ratio (AAR), AST to platelet ratio index (APRI) and prothrombin index (PI), was performed in 63 consecutive CHB patients who underwent MRE and histological confirmation of liver fibrosis within a 6-month interval. Diagnostic performance of MRE and serum markers for staging fibrosis (≥F1), significant fibrosis (≥F2), advanced fibrosis (≥F3) and cirrhosis (F4) was compared.

Results

The study group comprised 63 patients (19 female; mean age?±?SD, 50?±?11.9 years). MRE (ρ?=?0.94, P?<?0.0001), APRI (ρ?=?0.42, P?=?0.0006), PI (ρ?=?0.42, P?=?0.0006) and AST (ρ?=?0.28, P?=?0.028) results correlated significantly with fibrosis stage. MRE was significantly more accurate than serum fibrosis markers for the detection of significant fibrosis (0.99 vs. 0.55–0.73) and cirrhosis (0.98 vs. 0.53–0.77). Sensitivity, specificity, positive predictive and negative predictive values for MRE for significant fibrosis and cirrhosis were 97.4 %, 100 %, 100 % and 96 %, and 100 %, 95.2 %, 91.3 % and 100 %, respectively.

Conclusion

MRE is an accurate non-invasive technique for the detection and staging of liver fibrosis in CHB.

Key Points

? Magnetic resonance elastography is accurate for liver fibrosis detection and staging. ? MR elastography is more accurate than serum tests for staging liver fibrosis. ? MR elastography can potentially replace liver biopsy in chronic hepatitis B.     

声触诊组织量化技术对慢性乙型肝炎合并脂肪肝患者肝纤维化分级的阈值研究

目的 :探讨利用声触诊组织量化技术(VTQ)测定乙型肝炎(简称乙肝)合并脂肪肝患者各级纤维化剪切波速度的阈值。方法:测定311例慢性乙肝合并脂肪肝患者(肝病组)和100例健康人(对照组)的剪切波速度值,肝病组均经肝穿刺活检,并行病理肝纤维化分级及脂肪肝含量诊断,对不同肝纤维化分级及健康人群剪切波速度值进行对比分析。结果:对照组与肝纤维化分级S0组间剪切波速度值均值差异无统计学意义(P=0.87),肝病组间剪切波速度值均值两两比较差异均有统计学意义(均P0.05)。当VTQ阈值分别为1.16、1.42、1.51、1.92 m/s时,诊断肝纤维化≥S1、≥S2、≥S3、≥S4准确性、敏感度、特异度分别为87.2%、82.9%、85.7%;82.7%、76.0%、75.7%;90.5%、81.0%、81.0%;99.1%、93.0%、99.0%。结论 :剪切波速度测值评估乙肝合并脂肪肝患者肝纤维化分级有较高准确性、敏感度、特异度。     

Quantitative assessment of liver fibrosis in chronic viral hepatitis C patients using shear wave elastography with elastography point quantification feature

Introduction

Hepatic fibrosis is the underlying pathological condition in chronic hepatitis C virus (HCV) infection. Shear wave elastography (SWE) with elastography point quantification (ElastPQ) feature is a recently developed method for measuring tissue elasticity.

Real-time elastography with a novel quantitative technology for assessment of liver fibrosis in chronic hepatitis B

Background

The accurate evaluation of liver fibrosis stage is important in determining the treatment strategy. The limitations of percutaneous liver biopsy as the gold standard are obvious for invasion. Real-time elastography with conventional ultrasound probes and a new quantitative technology for diffuse histological lesion is a novel approach for staging of liver fibrosis.

Purpose

This study aimed to evaluate the value of real-time tissue elastography with a new quantitative technology for the assessment of liver fibrosis stage.

Materials and methods

Real-time elastography was performed in 55 patients with liver fibrosis and chronic hepatitis B and in 20 healthy volunteers. Eleven parameters for every patient in colorcode image obtained from the real-time elastography were analyzed with principal components analysis. We analyzed the correlation between elasticity index and liver fibrosis stage and the accuracy of real-time elastography for liver fibrosis staging. Additionally, aspartate transaminase-to-platelet ratio index was also included in the analysis.

Results

The Spearman's correlation coefficient between the elasticity index and the histologic fibrosis stage was 0.81, which is highly significant (p < 0.001). The areas under receiver operating characteristic curves indicating diagnostic accuracy were 0.93 (F ≥ F1, p < 0.001) for the diagnosis of liver fibrosis, 0.92 (F ≥ F2, p < 0.001), 0.84 (F ≥ F3, p < 0.05) and 0.66 (F = F4, p > 0.05), respectively.

Conclusions

Real-time elastography with a new quantitative technology for diffuse histological lesion is a new and promising sonography-based noninvasive method for the assessment of liver fibrosis in patients with chronic hepatitis B.     

Analysis of three ultrasound elastography techniques for grading liver fibrosis in patients with chronic hepatitis B

Background

Evaluation of liver fibrosis is important to assess prognosis and guide the treatment for chronic hepatitis B.

Objective

To analyze and compare transient, point, and two-dimensional (2D) shear wave elastography techniques in grading the liver fibrosis.

Methods

Based on the severity of liver inflammation and fibrosis (Scheuer criteria), 158 patients with chronic hepatitis B were assigned into group 1 (either G or S classification?<?2) or group 2 (either G or S classification?≥?2). Group 2 patients commonly require anti-viral treatment. All patients received transient (FibroScan), point (STQ), and 2D (STE) elastography examinations. Receiver operating characteristic curves were calculated from three elastography techniques in individual or in combination.

Results

A total of 158 patients were enrolled into the study, with 39.2% (62) female and mean age of 42.8 (standard deviation 19.1) years old. Transient elastography could not differentiate between group 1 and group 2 patients (P?=?0.12), whereas point and 2D elastography examinations could distinguish patients in group 1 from group 2 (P?<?0.01 for both STQ and STE). Administration of combined three elastography techniques showed the best diagnostic accuracy (90.1%) for liver fibrosis, which was confirmed with hepatic biopsy examination.

Conclusion

Point and 2D elastography were superior to transient elastography to detect liver fibrosis and guide clinical anti-viral treatment. Analysis of combined transient, point, and 2D elastography techniques showed the better diagnostic accuracy for liver fibrosis.

     

Diagnostic performance of shear wave elastography in the identification of malignant thyroid nodules: a meta-analysis

Objective

This meta-analysis aimed to assess the performance of shear wave elastography (SWE) in the identification of malignant thyroid nodules.

Methods

Web of Science, Scopus, PubMed, and the references of narrative reviews were searched for relevant studies with a publication date through October 2013. The methodological quality was assessed using QUADAS tools. Data synthesis was calculated using the bivariate mixed-effects regression model.

Results

Of the 131 studies identified, 15 (11.5 %) were included, in which SWE, point-SWE or 2D SWE, was used to evaluate 1,867 thyroid nodules in 1,525 patients. Methodological assessment revealed study quality was moderate to high. The pooled sensitivity, specificity, and area under the summary receiver operating characteristic curve of SWE for detecting malignant thyroid nodules were 84.3 % (95 % confidence interval [CI], 76.9–89.7 %), 88.4 % (95 % CI, 84.0–91.7 %), and 93 % (95 % CI, 90–95 %), respectively. As a screening tool, positive and negative predictive values were 27.7–44.7 % and 98.1–99.1 %, respectively, calculated with a malignance prevalence of 5–10 % in thyroid nodules. A publication bias regression test revealed no significant small-study bias.

Conclusions

SWE is a highly accurate diagnostic modality for the identification of malignant thyroid nodules, with promise for integration into routine imaging protocols for thyroid nodules.

Key Points

? Shear wave elastography (SWE) is a group of novel ultrasound-based technologies. ? Meta-analysis was employed to assess relevant studies of SWE of thyroid nodules. ? SWE had high sensitivity and specificity in identifying malignant thyroid nodules. ? The high negative predictive value of SWE can reduce unnecessary biopsies.     

Comparison of point and two-dimensional shear wave elastography of the spleen in healthy subjects

BACKGROUNDFew systematic comparative studies of the different methods of physical elastography of the spleen are currently available.AIMTo compare point shear wave and two-dimensional elastography of the spleen considering the anatomical location (upper, hilar, and lower pole).METHODSAs part of a prospective clinical study, healthy volunteers were examined for splenic elasticity using four different ultrasound devices between May 2015 and April 2017. The devices used for point shear wave elastography were from Siemens (S 3000) and Philips (Epiq 7), and those used for two-dimensional shear wave elastography were from GE (Logiq E9) and Toshiba (Aplio 500). In addition, two different software versions (5.0 and 6.0) were evaluated for the Toshiba ultrasound device (Aplio 500). The study consisted of three arms: A, B, and C.RESULTSIn study arm A, 200 subjects were evaluated (78 males and 122 females, mean age 27.9 ± 8.1 years). In study arm B, 113 subjects were evaluated (38 men and 75 women, mean age 26.0 ± 6.3 years). In study arm C, 44 subjects were enrolled. A significant correlation of the shear wave velocities at the upper third of the spleen (r = 0.33088, P < 0.0001) was demonstrated only for the Philips Epiq 7 device compared to the Siemens Acuson S 3000. In comparisons of the other ultrasound devices (GE, Siemens, Toshiba), no comparable results could be obtained for any anatomical position of the spleen. The influencing factors age, gender, and body mass index did not show a clear correlation with the measured shear wave velocities.CONCLUSIONThe absolute values of the shear wave elastography measurements of the spleen and the two different elastography methods are not comparable between different manufacturers or models.     

Transient elastography with a new probe for obese patients for non-invasive staging of non-alcoholic steatohepatitis

Objective

Transient elastography (TE) has shown promising results for the staging of liver fibrosis in patients with non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) with the limitation that 25% of obese patients cannot be examined with the standard TE probe. The aim of this study was to evaluate a new XL probe for obese patients for the staging of liver fibrosis in NAFLD/NASH.

Methods

Fifty patients with NAFLD/NASH and histological assessment of liver fibrosis were included in the study. All patients received TE with the standard probe (M probe) and the new XL probe, and the results were compared with liver histology.

Results

The diagnostic accuracy expressed as the area under the ROC curve for TE measurements with the M probe and the XL probe was 0.80 and 0.82 for the diagnosis of significant fibrosis, and 0.91 and 0.95 for the diagnosis of liver cirrhosis, respectively. Eighty-three percent of the patients who could not be measured with the M probe could be measured using the XL probe.

Conclusion

Transient elastography using the XL probe for obese patients can be performed with comparable diagnostic accuracy to the standard probe and enables the examination of significantly more obese patients.     

超声弹性成像参数诊断慢性乙型肝炎肝纤维化临床分析

目的 探讨超声弹性成像(RTE)参数在慢性乙肝肝纤维化中诊断价值.方法 选取我院慢性乙肝肝纤维化患者79例设为观察组,另选取同期健康体检者79例设为对照组.两组均实施RTE检查,并给予观察组对应治疗措施.对比观察组及对照组、观察组不同疾病分期患者RTE参数[峰度(KURT)、偏度(SKEW)、复杂度(COMP)、对比度...     

Diagnostic value of real-time elastography in the assessment of hepatic fibrosis in patients with liver iron overload

Objective

The objective of our prospective monocentric work was to determine the diagnostic value of real-time elastography (RTE) in the assessment of liver fibrosis in patients with iron overload, using transient elastography (TE) as reference standard.

Methods

Sixty-seven consecutive patients with MRI detectable iron overload (T2* < 6.3 ms) were enrolled. TE and RTE were performed on the same day as MRI. Elastograms were acquired by an experienced operator and analyzed by calculating the elastic ratio between perihepatic soft tissues and liver parenchyma. An elliptical ROI of 1 cm² (Z₁) was positioned in the liver parenchyma and a smaller elliptical ROI of 2 mm² (Z₂) was positioned in a homogeneously soft (red) region of the diaphragm, which was considered as internal control to calculate the elastic ratio Z₂/Z₁.

Results

Seven patients were excluded because of invalid TE or RTE examinations. The remaining 60 patients were 57% males and 43% females (mean age: 42 [21–76] years), including 37 homozygous-β-thalassemics, 13 patients with β-thalassemia intermedia, 6 with primary hemochromatosis, and 4 with myelodysplastic syndrome. Increasing elastic ratios were significantly correlated with increasing TE values (r = 0.645, 95% CI 0.468–0.772, P < 0.0001). The mean elastic ratios for each METAVIR group were as follows: F0/1 = 1.9 ± 0.4; F2 = 2.2 ± 0.4; F3 = 2.9 ± 0.5; F4 = 3.2 ± 0.4. The diagnostic accuracy of RTE for F ≥ 2 evaluated by AUC-ROC analysis was 0.798 (95% CI 0.674–0.890). The diagnostic accuracy of RTE for F ≥ 3 was 0.909 (95% CI 0.806–0.968). At a cut-off ≥ 2.75, RTE showed a sensitivity of 70% (95% CI 45.7–88.1) and a specificity of 97.5% (95% CI 86.8–99.9).

Conclusions

In patients with MRI-detectable liver iron-overload RTE allows to discriminate between F0/1–F2 and F3–F4 with a reasonable diagnostic accuracy.     

"益肝康"治疗90例慢性乙型肝炎肝纤维化疗效观察

 目的试图从临床角度探讨"益肝康"对慢性乙肝肝纤维化疗效.方法共90例慢性乙肝患者随机分为两组,分别于治疗前后作肝功能、血清肝纤维化指标检测,进行疗效评价.结果"益肝康"治疗后,同对照组相比可明显降低血浆透明质酸(HA)、层粘蛋白(LN)和Ⅲ型前胶原(PCⅢ)水平,同时,患者肝功能明显好转,白蛋白水平升高.结论"益肝康"是有效的治疗慢性肝病、肝纤维化药物.     

Non-invasive evaluation of liver fibrosis: a comparison of ultrasound-based transient elastography and MR elastography in patients with viral hepatitis B and C

Objective

To compare the diagnostic accuracy of TE and MRE and establish cutoff levels and diagnostic strategies for both techniques, enabling selection of patients for liver biopsy.

Methods

One hundred three patients with chronic hepatitis B or C and liver biopsy were prospectively included. Areas under curves (AUROC) were compared for TE and MRE for METAVIR fibrosis grade?≥?F2 and ≥F3. We defined cutoff values for selection of patients with F0–F1 (sensitivity >95 %) and for significant fibrosis F2–F4 (specificity >95 %).

Results

Following exclusions, 85 patients were analysed (65 CHB, 19 CHC, 1 co-infected). Fibrosis stages were F0 (n?=?3), F1 (n?=?53), F2 (n?=?15), F3 (n?=?8) and F4 (n?=?6). TE and MRE accuracy were comparable [AUROC_TE?≥?F2: 0.914 (95 % CI: 0.857–0.972) vs. AUROC_MRE?≥?F2: 0.909 (0.840–0.977), P?=?0.89; AUROC_TE?≥?F3: 0.895 (0.816–0.974) vs. AUROC_MRE?≥?F3: 0.928 (0.874–0.982), P?=?0.42]. Cutoff values of <5.2 and ≥8.9 kPa (TE) and <1.66 and ≥2.18 kPa (MRE) diagnosed 64 % and 66 % of patients correctly as F0–F1 or F2–F4. A conditional strategy in inconclusive test results increased diagnostic yield to 80 %.

Conclusion

TE and MRE have comparable accuracy for detecting significant fibrosis, which was reliably detected or excluded in two-thirds of patients. A conditional strategy further increased diagnostic yield to 80 %.

Key Points

? Both ultrasound-based transient elastography and magnetic resonance elastography can assess hepatic fibrosis. ? Both have comparable accuracy for detecting liver fibrosis in viral hepatitis. ? The individual techniques reliably detect or exclude significant liver fibrosis in 66 %. ? A conditional strategy for inconclusive findings increases the number of correct diagnoses.     

慢性乙型肝炎及其合并脂肪肝患者各级纤维化声触诊组织量化技术测值的对比研究

目的:探讨脂肪肝对乙型肝炎(乙肝)患者声触诊量化技术(VTQ)测值的影响。方法:回顾性分析行肝穿刺活检的311例慢性乙肝患者VTQ值和311例慢性乙肝合并脂肪肝患者VTQ值。根据肝纤维化病理分级分别对上述2类患者分组(S0、S1、S2、S3、S4),并对其同级别纤维化的VTQ均值行独立样本t检验。结果:慢性乙肝患者无肝纤维化分级S0级,其S1~S4级的VTQ值与慢性乙肝合并脂肪肝相比差异均无统计学意义(均P0.05)。结论:慢性乙型肝炎与慢性乙型肝炎合并脂肪肝患者同级别纤维化VTQ值无明显差异。     

Non-invasive biomechanical characterization of intervertebral discs by shear wave ultrasound elastography: a feasibility study

Objectives

Although magnetic resonance is widely spread to assess qualitatively disc morphology, a simple method to determine reliably intervertebral disc status is still lacking. Shear wave elastography is a novel technique that allows quantitative evaluation of soft-tissues’ mechanical properties. The aim of this study was to assess preliminary the feasibility and reliability of mechanical characterization of cervical intervertebral discs by elastography and to provide first reference values for asymptomatic subjects.

Methods

Elastographic measurements were performed to determine shear wave speed (SWS) in C6-C7 or C7-T1 disc of 47 subjects; repeatability and inter-operator reproducibility were assessed.

Results

Global average shear wave speed (SWS) was 3.0?±?0.4 m/s; measurement repeatability and inter-user reproducibility were 7 and 10 %, respectively. SWS was correlated with both subject’s age (p?=?1.3?×?10^?5) and body mass index (p?=?0.008).

Conclusions

Shear wave elastography in intervertebral discs proved reliable and allowed stratification of subjects according to age and BMI. Applications could be relevant, for instance, in early detection of disc degeneration or in follow-up after trauma; these results open the way to larger cohort studies to define the place of this technique in routine intervertebral disc assessment.

Key Points

? A simple method to obtain objectively intervertebral disc status is still lacking ? Shear wave elastography was applied in vivo to assess intervertebral discs ? Elastography showed promising results in biomechanical disc evaluation ? Elastography could be relevant in clinical routine for intervertebral disc assessment