Quantitative evaluation of pancreatic tumor fibrosis using shear wave elastography

Background & aimsThere is no established non-invasive method for diagnosis of pancreatic fibrosis. Shear wave elastography (SW-EG) may be a candidate for this purpose. The aims of this study were to assess the reproducibility of SW-EG in the normal imaging pancreas (Phase 1) and to evaluate the diagnostic performance of SW-EG for pancreatic fibrosis classified histologically (Phase 2).MethodsPhase 1: This included 127 cases that underwent SW-EG of the normal imaging pancreas. SW-EG was measured at least five times in the pancreatic parenchyma and the median of repeated measurements was defined as the pancreatic elastic modulus (PEM). Phase 2: This included 53 cases that underwent SW-EG of the pancreatic parenchyma preoperatively and in which pancreas parenchyma were evaluated histologically. Histological fibrosis was graded in 4 stages: normal, mild, moderate, and severe.ResultsPhase 1: Median PEM in the head, body, and tail of the pancreas were 3.23, 3.17, and 2.91 kPa, respectively, with no significant difference among regions (P = 0.554). The intraclass correlation coefficient showed good reproducibility (ρ = 0.71) after 5 measurements. Phase 2: There was a significant positive correlation between PEM and the histological pancreatic fibrosis stage (r_s = 0.63, P < 0.001). Areas under the receiver operating characteristic curve for the accuracy of SW-EG for diagnosis of pancreatic fibrosis were 0.85 (≥mild), 0.84 (≥moderate), and 0.87 (severe).ConclusionSW-EG can be used to determine the stage of pancreatic fibrosis non-invasively with high accuracy and reproducibility.     

Comparison of 2 shear wave elastography systems in reproducibility and accuracy using an elasticity phantom

This study aimed to compare the accuracy and inter- and intra-observer reproducibility of the measured elasticity between 2 shear wave elastography systems. Three breast radiologists examined 8 targets of 4 different levels of stiffness (size: 11 mm, 4 mm) in an elasticity phantom (Customized 049A Elasticity QA Phantom, CIRS, Norfolk, VA, USA) using 2 different shear wave ultrasound elastography systems: SuperSonic Imagine (SSI) (SSI, Aix en Provence, France) and ShearScan (RS-80A, Samsung Medison, Seoul, Korea). Three radiologists performed ultrasound (US) elastography examinations for the phantom lesions using 2 equipment over a 1-week interval. Intra- and inter-observer reproducibility and the accuracy of the measured elasticity were analyzed and compared between the 2 systems. The accuracy of shape was also analyzed by shape-matching between B-mode and elastography color image. Intra-class correlation coefficients (ICC) were used in statistical analysis. For measured elasticity, the intra-observer and inter-observer reproducibility were excellent in both SSI and ShearScan (0.994 and 0.998). The overall accuracy was excellent in both systems, but the accuracy in small lesions (4 mm target) was lower in SSI than ShearScan (0.780 vs 0.967). The accuracy of shape-matching on the elastography image was 59.0% and 81.4% in the SSI and ShearScan, respectively. In conclusion, the SSI and ShearScan showed excellent intra- and inter-observer reproducibility. The accuracy of the Young''s modulus was high in both the SSI and ShearScan, but the SSI showed decreased accuracy in measurement of elasticity in small targets and poor shape-matching between the B-mode image and color-coded elastography image.     

Value of shear wave elastography with maximal elasticity in differentiating benign and malignant solid focal liver lesions

BACKGROUNDIt is important to differentiate benign and malignant focal liver lesions (FLLs) accurately. Despite the wide use and acceptance of shear wave elastography (SWE), its value for assessing the elasticity of FLLs and differentiating benign and malignant FLLs is still investigational. Previous studies of SWE for FLLs used mean elasticity as the parameter to reflect the stiffness of FLLs. Considering the inhomogeneity of tumor stiffness, maximal elasticity (Emax) might be the suitable parameter to reflect the stiffness of FLLs and to differentiate malignant FLLs from benign ones.AIMTo explore the value of SWE with Emax in differential diagnosis of solid FLLs.METHODSWe included 104 solid FLLs in 95 patients and 50 healthy volunteers. All the subjects were examined using conventional ultrasound (US) and virtual touch tissue quantification(VTQ) imaging. A diagnosis of benign or malignant FLL was made using conventional US. Ten VTQ values were acquired after 10 consecutive measurements for each FLL and each normal liver, and the largest value was recorded as Emax.RESULTSThere were 56 cases of malignant FLLs and 48 cases of benign FLLs in this study. Emax of malignant FLLs (3.29 ± 0.88 m/s) was significantly higher than that of benign FLLs (1.30 ± 0.46 m/s, P < 0.01) and that of livers in healthy volunteers (1.15 ± 0.17 m/s, P < 0.01). The cut-off point of Emax was 1.945, and the area under the curve was 0.978. The sensitivity and specificity of Emax were 92.9% and 91.7%, respectively, higher (but not significantly) than those of conventional US (80.4% for sensitivity and 81.3% for specificity). Combined diagnosis of conventional US and Emax using parallel testing improved the sensitivity to 100% with specificity of 75%.CONCLUSIONSWE is a convenient and easy method to obtain accurate stiffness information of solid FLLs. Emax is useful for differential diagnosis of FLLs, especially in combination with conventional US.     

Study of detection times for liver stiffness evaluation by shear wave elastography

AIM: To investigate enough valid measurements (VMs) to assess liver fibrosis in chronic hepatitis B patients (CHB).METHODS: One hundred and twelve CHB patients (25 women, 87 men) with a mean age of 38.43 years received liver stiffness evaluations using real-time shear wave elastography for 10 VMs. All patients underwent liver biopsy. Based on the biopsy pathology, the liver stiffness data obtained from different VMs (1, 2, 3, 5 and 10 times) were compared for the evaluation of liver fibrosis. The correlation between the elastic modulus means of the liver obtained from different VMs of detection at each pathological stage was analysed. The receiver operating characteristic (ROC) curve was employed to determine the diagnostic performance of different VMs of detection, and the areas under the ROC curve of different groups were compared.RESULTS: The liver stiffness values obtained from 1 VM, 2 VMs, 3 VMs, 5 VMs and all 10 VMs for stage F0 were 6.95 ± 2.01 kPa, 6.87 ± 1.83 kPa, 6.90 ± 1.88 kPa, 6.95 ± 1.93 kPa and 7.15 ± 1.89 kPa, respectively (F = 0.043, P = 0.996). For stage F1, these values were 7.12 ± 1.72 kPa, 7.24 ± 1.72 kPa, 7.21 ± 1.74 kPa, 7.10 ± 1.78 kPa and 7.04 ± 1.70 kPa, respectively (F = 0.075, P = 0.990). For stage F2, they were 9.37 ± 3.87 kPa, 9.18 ± 3.68 kPa, 9.19 ± 3.81 kPa, 9.18 ± 3.81 kPa and 9.19 ± 3.53 kPa, respectively (F = 0.012, P = 1.000). For stage F3, these were 11.91 ± 3.88 kPa, 11.78 ± 4.04 kPa, 11.83 ± 4.07 kPa, 11.94 ± 4.17 kPa and 12.00 ± 4.02 kPa, respectively (F = 0.010, P = 1.000). For stage F4, the readings were 19.30 ± 7.63 kPa, 19.40 ± 7.36 kPa, 19.54 ± 7.43 kPa, 19.73 ± 7.21 kPa and 20.25 ± 7.22 kPa, respectively (F = 0.054, P = 0.995). There were no significant differences between these groups. Intraclass correlation coefficients among different pathological stages (F0-F4) with different detection VMs were 0.995, 0.993, 0.996, 0.994 and 0.996, respectively. The mean elasticity values from 1 VM, 2 VMs, 3 VMs, 5 VMs and 10 VMs can accurately distinguish fibrosis stages (F0 vs F1234, F01 vs F234, F012 vs F34 and F0123 vs F4) with no significant differences in the five groups (P > 0.05 for all).CONCLUSION: One VM may be sufficient to assess liver fibrosis by using SWE without any significant loss of accuracy in patients with CHB. However, future studies of larger patient samples are necessary for the validation of this method.     

直肠腔内剪切波弹性成像对局部进展期直肠癌新辅助放化疗后T分期的价值

目的探讨经直肠腔内超声弹性成像对局部进展期直肠癌新辅助放化疗后T分期的应用价值。 方法收集就诊于中国医学科学院肿瘤医院的局部进展期直肠癌患者57例,均于术前接受新辅助放化疗,并进行根治性手术。所有患者新辅助放化疗前后行经直肠腔内超声（ERUS）及剪切波弹性成像（SWE）检查。以术后病理为金标准,评价ERUS及SWE对直肠癌新辅助放化疗后T分期的准确性。 结果ERUS对局部进展期直肠癌新辅助放化疗后T分期的诊断准确率为59.6%（34/57）。ERUS判断肿瘤局限于肠壁（T0~T2）的准确性为39.3%（11/28）。46.2%（6/13）的ypT0期患者被过高分期。放化疗前后,杨氏模量最大值（Emax）平均值分别为（103.27±29.23）kPa、（49.91±32.67）kPa,差异有统计学意义（t=6.236,P<0.001）。新辅助治疗后病理T分期越高,Emax平均值随之升高。以放化疗后病灶Emax构建ROC曲线,选取58 kPa作为最佳诊断临界点时,诊断放化疗后残余病变局限于肠壁内的敏感性、特异性、准确性分别为76.2%、86.4%、78.9%;以43 kPa为最佳诊断临界点,诊断ypT0期的敏感性、特异性、准确性分别为100%、84.6%、89.7%,均较ERUS有改善,说明SWE可提高新辅助治疗后直肠癌再分期的准确性,有助于临床治疗方案的制定。 结论经直肠腔内SWE可提高局部进展期直肠癌新辅助放化疗后T分期的准确性,可丰富现有影像检查方法。     

Added value of deep learning-based computer-aided diagnosis and shear wave elastography to b-mode ultrasound for evaluation of breast masses detected by screening ultrasound

Low specificity and operator dependency are the main problems of breast ultrasound (US) screening. We investigated the added value of deep learning-based computer-aided diagnosis (S-Detect) and shear wave elastography (SWE) to B-mode US for evaluation of breast masses detected by screening US.Between February 2018 and June 2019, B-mode US, S-Detect, and SWE were prospectively obtained for 156 screening US-detected breast masses in 146 women before undergoing US-guided biopsy. S-Detect was applied for the representative B-mode US image, and quantitative elasticity was measured for SWE. Breast Imaging Reporting and Data System final assessment category was assigned for the datasets of B-mode US alone, B-mode US plus S-Detect, and B-mode US plus SWE by 3 radiologists with varied experience in breast imaging. Area under the receiver operator characteristics curve (AUC), sensitivity, and specificity for the 3 datasets were compared using Delong''s method and McNemar test.Of 156 masses, 10 (6%) were malignant and 146 (94%) were benign. Compared to B-mode US alone, the addition of S-Detect increased the specificity from 8%–9% to 31%–71% and the AUC from 0.541–0.545 to 0.658–0.803 in all radiologists (All P < .001). The addition of SWE to B-mode US also increased the specificity from 8%–9% to 41%–75% and the AUC from 0.541–0.545 to 0.709–0.823 in all radiologists (All P < .001). There was no significant loss in sensitivity when either S-Detect or SWE were added to B-mode US.Adding S-Detect or SWE to B-mode US improved the specificity and AUC without loss of sensitivity.     

Role of two-dimensional shear wave elastography in chronic liver diseases: A narrative review

Liver biopsy is the gold standard for evaluating the degree of liver fibrosis in patients with chronic liver disease. However, due to the many limitations of liver biopsy, there has been much interest in the use of noninvasive techniques for this purpose. Among these techniques real-time two-dimensional shear wave elastography(2D-SWE) has the advantage of measuring tissue elasticity with the guidance of B-mode images. Recently, many studies have been conducted on the application of 2D-SWE in patients with various liver diseases, and their validity has been confirmed. Here, we briefly discuss the role of 2D-SWE in patients with chronic liver diseases, particularly aspects of the examination techniques and clinical applications.     

Shear-wave versus strain elastography in endoscopic ultrasound for the diagnosis of chronic pancreatitis

Background/Objectives: Endoscopic ultrasound (EUS) elastography is a non-invasive diagnostic method for evaluating tissue elasticity. The aims of this study were to compare shear-wave elastography (SWE) and conventional strain elastography (SE) in determination of the diagnosis and degree of chronic pancreatitis (CP).MethodsForty-nine patients who underwent computed tomography (CT), EUS-SWE, EUS-SE, and pancreatic exocrine function testing between January 2019 and January 2022 were prospectively evaluated. CP was diagnosed according to Japan Pancreatic Society criteria (JPSC) 2019, Rosemont criteria (RC), CT findings, and pancreatic exocrine dysfunction. The cut-off values, sensitivity, and specificity for CP diagnosed according to the four criteria were calculated for EUS-SWE and EUS-SE. Relationships between values measured by either of the EUS elastography methods and the number of EUS features were also assessed.ResultsEUS-SWE values were positively correlated with the severity grades of RC and JPSC, but EUS-SE values were not. EUS-SWE was significantly better than EUS-SE for diagnosing CP defined according to CT findings (area under the receiver operating characteristics curve [AUROC]: 0.77 vs. 0.61, P < 0.001), RC (AUROC: 0.85 vs. 0.56, P < 0.001), JPSC 2019 (AUROC: 0.83 vs. 0.53, P < 0.001), and exocrine dysfunction (AUROC: 0.78 vs. 0.61, P < 0.001). EUS-SWE values were positively correlated with the number of EUS features, but EUS-SE values were not.ConclusionsEUS-SWE provides objective assessment for diagnosing and assessing the degree of CP defined according to the criteria of CT findings, RC, JPSC, or exocrine dysfunction, and it can be considered a non-invasive diagnostic tool for CP and exocrine dysfunction.     

Application of transperineal ultrasound combined with shear wave elastography in pelvic floor function assessment after hysterectomy

This study explored the application of transperineal ultrasound (TPUS) combined with shear wave elastography (SWE) in evaluating the pelvic structure function of women after total hysterectomy. Seventy healthy women and 76 women who underwent total hysterectomy were selected for ultrasound examination. They were divided into normal (nulliparous) group, (parous) group without hysterectomy, and (parous) group with hysterectomy. TPUS combined with SWE was used to evaluate the pelvic floor structure and function in the 3 groups of women. Posterior urethrovesical angle in resting and maximal Valsalva state, anteroposterior diameter of hiatus in the 3 states, the bladder neck descent, the urethral rotation angle, the Young modulus of left and right puborectalisis muscle in resting state, and the incidence of pelvic floor dysfunction diseases were all higher in the group with hysterectomy than in the group without hysterectomy (P < .05). Bladder neck-symphyseal distance and anorectal junction-symphyseal distance in the maximum Valsalva state, and the difference in Young modulus between the left and right PR before and after anus contraction were all lower in the group with hysterectomy than the group without hysterectomy (P < .05). The incidence of pelvic floor dysfunction in postmenopausal patients in the group with hysterectomy was higher than that in premenopausal patients (P < .05). Total hysterectomy had negative effects on female pelvic floor structure and function. TPUS combined with SWE can be used to evaluate pelvic floor function in multiple dimensions.     

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

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

Comparing the accuracy between shear wave elastography and strain elastography in the diagnosis of breast tumors: Systematic review and meta-analysis

Background:Shear wave elastography and strain elastography are two new ultrasonic techniques developed rapidly in recent years. Changes in tissue elasticity occur after normal tissue changes. Elastography technique transforms the elastic information of tissue into optical information for display. Thus more intuitive display of tissue elasticity. Due to the differences in principles and related imaging parameters between the two elastic imaging methods, and the acquisition and interpretation of image data in strain elastic imaging method largely depends on the experience of inspectors, and due to the significant differences between the techniques of inspectors, As a result, conflicting results have been obtained in different scholars’ studies on the accuracy comparison of the two elastography techniques in the diagnosis of breast tumors. This meta-analysis aims to compare the accuracy of the two elastography methods in the diagnosis of breast tumors, so as to provide more accurate diagnostic means for patients with breast tumors. The final results will show which elastography method is more accurate in the diagnosis of breast tumors, reduce unnecessary biopsies and provide a reference for clinical decision making.Methods:We will examine published and unpublished randomized controlled trials, observational studies and abstracts without publication type or language restrictions, and search relevant literatures in PubMed, Web of Science, Wanfang Database, CNQI and other databases until December 30, 2020. The authors will independently search relevant literature records, scan titles and abstracts, full text, collect data and assess the risk of bias. Data will be analyzed by using Meta Disc1.4 software and Stata14.0 software. Heterogeneity tests and combined sensitivity, specificity, positive and negative likelihood ratio, diagnostic odds ratio, and area under the summary receiver operating characteristic curve will be performed by using Meta Disc1.4 software. Stata14.0 software will be used for sensitivity analysis and publication bias test.Results:The results of this systematic review will demonstrate the accuracy of the two elastography methods in the diagnosis of breast tumors.Discussion:The results will provide useful evidence for the comparison of the diagnostic accuracy of shear wave elastography and strain elastography in breast tumors.Other:This study was not funded. Register name: PROSPERO. Registration number: CRD42021251110.     

Usefulness of noninvasive methods including assessment of liver stiffness by 2-dimensional shear wave elastography for predicting esophageal varices

BackgroundThe aim of this study was to predict the presence of esophageal varices (EVs) by noninvasive tools combined with 2-dimensional shear wave elastography (2D-SWE), and to compare the diagnostic capabilities of 2D-SWE with those of transient elastography (TE).MethodsBetween January 2015 and December 2017, 289 patients with compensated advanced chronic liver disease (cACLD) who underwent consecutive 2D-SWE and EGD were enrolled. Capabilities for predicting the presence of EVs of 2D-SWE and models combining 2D-SWE with other noninvasive tools (modified LS-spleen-diameter-to-platelet-ratio score [mLSPS], platelet-spleen ratio score) were compared. A subgroup analysis was performed on 177 patients who also underwent simultaneous TE.ResultsThe area under receiver operating characteristics (AUROCs) for detecting EVs for 2D-SWE alone vs. mLSPS, which included 2D-SWE, were 0.757 (95% confidence interval [CI], 0.701–0.810) and 0.813 (95% CI, 0.763–.857), respectively. The AUROCs for predicting varices needing treatment (VNT) for 2D-SWE and mLSPS were 0.712 (95% CI, 0.621–0.738) and 0.834 (95% CI, 0.785–0.875), respectively. For the 195 patients who underwent simultaneous TE and 2D-SWE, no differences in diagnostic performance were observed.ConclusionsThe diagnostic performance of 2D-SWE is similar to that of TE for predicting the presence of EVs. The mLSPS, which includes 2D-SWE, seemed to be useful for predicting EVs.