Shear wave elastography of the tibial nerve in healthy subjects

The purpose of this study is to investigate sonoelastographic features of the tibial nerve.The study included 72 tibial nerves in 36 healthy subjects. High resolution ultrasound and Shear wave elastography were used to evaluate the tibial nerve. Cross sectional area and stiffness were measured.The mean cross sectional area of the tibial nerve was 13.4 mm². The mean shear elastic modulus of the tibial nerve in the short axis was 23.3 kPa. The mean shear elastic modulus of the tibial nerve in long axis was 26.1 kPa. The tibial nerve elastic modulus also showed no correlation with cross sectional area neither in the long axis nor short axis. Age, height, weight, and body mass index showed no correlation with tibial nerve elastic modulus in short or long axes.The elastic modulus of the tibial nerve has been determined in healthy subjects and can serve as a reference for future assessment of polyneuropathy.     

Shear wave elastography of the scalene muscles in healthy adults: A preliminary study

The aim of the study is to evaluate the reliability of shear wave elastography to assess the anterior and middle scalene muscles in healthy adult subjects.The study included 60 scalene muscles in 15 healthy subjects. High-resolution ultrasound and shear wave elastography were used to evaluate the anterior scalene and the middle scalene muscles. Stiffness values were measured.The mean shear elastic modulus showed the following values, right anterior scalene muscle 18.83 ± 5.32 kPa, left anterior scalene muscle 21.71 ± 4.8 kPa, right middle scalene muscle 12.84 ± 5.2 kPa, left middle scalene muscle 19.76 ± 5.30 kPa. Positive correlation was noted between the left middle scalene muscle and body mass index (P = .004). No difference in elasticity was noted between the right and left anterior scalene muscles; however, significant difference was noted between the right and left middle scalene muscles (P = .002).The results obtained in our study could be a reference point for future research considering different scalene muscle pathologies.     

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.     

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.     

Value of shear wave elastography combined with the Toronto clinical scoring system in diagnosis of diabetic peripheral neuropathy

To evaluate the diagnostic values of shear wave elastography (SWE) alone and in combination with the Toronto clinical scoring system (TCSS) on diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes mellitus (T2DM).The study included 41 DPN patients, 42 non-DPN patients, and 21 healthy volunteers. Conventional ultrasonography and SWE were performed on the 2 sides of the tibial nerves, and cross-sectional area (CSA) and nerve stiffness were measured. TCSS was applied to all patients. A receiver operating characteristic curve analysis was performed.The stiffness of the tibial nerve, as measured as mean, minimum or maximum elasticity, was significantly higher in patients in the DPN group than the other groups (P < .05). The tibial nerve of subjects in the non-DPN group was significantly stiffer compared to the control group (P < .05). There was no significant difference of the tibial nerve CSA among the 3 groups (P > .05). Mean elasticity of the tibial nerve with a cutoff of 71.3 kPa was the most sensitive (68.3%) and had a higher area under the curve (0.712; 0.602–0.806) among the 3 shear elasticity indices for diagnosing DPN when used alone. When combining SWE with TCSS in diagnosing DPN, the most effective parameter was the EMax, which yielded a sensitivity of 100.00% and a specificity of 95.24%.SWE is a better diagnostic tool for DPN than the conventional ultrasonic parameter CSA, and a higher diagnostic value is attained when combining SWE with TCSS.     

两种超声弹性成像技术诊断慢性乙型肝炎患者肝纤维化价值比较*

目的 探讨瞬时弹性成像和二维剪切波弹性成像用于CHB患者肝纤维化诊断的临床价值。方法 2016年3月～2018年12月我院收治的CHB患者164例,均行瞬时弹性成像和二维剪切波弹性成像检查及肝穿刺活检,采用受试者工作特性(ROC)曲线下面积比较两种超声弹性成像检查诊断不同肝纤维化分期的效能。结果 经肝穿刺活检,在164例CHB患者中,诊断肝组织S₁期50例,S₂期42例,S₃期39例,S₄期33例;瞬时弹性成像检查S₁～S₄期肝纤维化分期的弹性值分别为(6.5±1.1)kPa、(8.6±1.4)kPa、(11.7±1.8)kPa和(16.3±1.8)kPa,二维剪切波弹性成像检查弹性值分别为(5.9±0.8) kPa、(8.1±1.2)kPa、(10.9±1.5)kPa和(16.7±1.9) kPa,两种超声弹性成像检查不同肝纤维化分期弹性值差异无统计学意义(P >0.05);二维剪切波弹性成像检查诊断肝纤维化S₂、S₃和S₄期的ROC曲线下面积(AUC)分别为0.971、0.979和0.973,显著高于瞬时弹性成像检查的0.902、0.906和0.904(P <0.05),其诊断的敏感性分别为90.3%、90.6%和100.0%,特异性分别为95.8%、90.6%和84.5%,而瞬时弹性成像检查诊断则分别为78. 5%、81.3%和73.1%,和93.3%、87.9%和91.0%。结论 二维剪切波弹性成像和瞬时弹性成像检查均可用于慢性乙型肝炎患者的肝纤维化诊断,其临床价值均需要进一步探讨。     

Accuracy and reproducibility of shear wave elastography according to the size and elasticity of lesions: A phantom study

While the extrinsic factors affecting reproducibility of shear wave elastography (SWE) have been well documented, there are few resources assessing intrinsic characteristics of the lesion affecting the reproducibility and accuracy of SWE. In this regard, this study aimed to evaluate the accuracy of measured elasticity and the reproducibility of SWE according to the lesion size and stiffness. Two breast radiologists examined 20 targets of 4 different levels of stiffness and 5 different sizes (2.5, 4, 7, 11, and 18 mm) in a customized elasticity phantom. The B-mode image, color elastography image, and kPa measurement were obtained twice by each examiner with a 1-week interval. Inter- and intra-observer reproducibility and the accuracy of measured kPa were analyzed using intraclass correlation coefficient (ICC) and Bland-Altman analysis. Subgroup analysis was run to evaluate the effect of lesion size and stiffness on the reproducibility and accuracy of measured kPa. Inter- and intraobserver reproducibility for measuring kPa showed excellent agreement (ICC: 0.9742 and 0.9582; ICC: 0.9932 and 0.9294). The size and stiffness of the targets did not affect reproducibility. The overall accuracy of measured kPa was very high (ICC: 0.8049). In the subgroup analysis, targets that were ≤4 mm in size showed lower accuracy (ICC: 0.542), whereas targets that were 7 and 11 mm in size showed higher accuracy (ICC: 0.9832 and 0.9656, respectively). SWE shows excellent reproducibility regardless of lesion size or stiffness in phantom targets. The accuracy of measured kPa is high in lesions that are 7 and 11 mm in size but is low in lesions that are ≤4 mm in size.     

Vibrotactile sense in median and ulnar nerve innervated fingers of men with Type 2 diabetes,normal or impaired glucose tolerance

Aims To investigate vibrotactile sense (large fibre neuropathy) at different frequencies in index and little fingers (median and ulnar nerves, respectively) of subjects with diabetes, or impaired (IGT) or normal glucose tolerance (NGT). Methods Vibration thresholds (tactilometry at seven frequencies (8, 16, 32, 64, 125, 250 and 500 Hz)) and median nerve function (electrophysiology) were examined in men (age 73.4 ± 0.12 years; n = 58, mean ± sd ) with persistent NGT (n = 28) or IGT (n = 7) or with Type 2 diabetes mellitus (T2DM) (n = 23) for > 15 years. Results HbA_1c was increased and vibrotactile sense (sensibility index) was impaired in index and little fingers in men with T2DM. Vibration thresholds were particularly increased at 16, 250 and 500 Hz in the little finger (ulnar nerve). T2DM subjects showed electrophysiological (gold standard) signs of neuropathy in the median nerve. Although subjects with persistent IGT had higher HbA_1c, vibrotactile sensation and electrophysiology remained normal. HbA_1c did not correlate with vibrotactile sense or electrophysiology, but the latter two correlated with respect to Z-score (sign of neuropathy) in forearm (NGT) and at wrist level (NGT and DM). Conclusions Vibration thresholds are increased in the finger pulps in T2DM subjects, particularly at specific frequencies in ulnar nerve innervated finger pulps. Neuropathy is not present in IGT. Tactilometry, with a multi-frequency approach, is a sensitive technique to screen for large fibre neuropathy in T2DM. Frequency-related changes may mirror dysfunction of various receptors.     

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.     

Shear wave elastography results correlate with liver fibrosis histology and liver function reserve

AIM: To evaluate the correlation of shear wave elastography (SWE) results with liver fibrosis histology and quantitative function reserve. METHODS: Weekly subcutaneous injection of 60% carbon tetrachloride (1.5 mL/kg) was given to 12 canines for 24 wk to induce experimental liver fibrosis, with olive oil given to 2 control canines. At 24 wk, liver condition was evaluated using clinical biochemistry assays, SWE imaging, lidocaine metabolite monoethylglycine-xylidide (MEGX) test, and histologic fibrosis grading. Clinical biochemistry assays were performed at the institutional central laboratory for routine liver function evaluation. Liver stiffness was measured in triplicate from three different intercostal spaces and expressed as mean liver stiffness modulus (LSM). Plasma concentrations of lidocaine and its metabolite MEGX were determined using high-performance liquid chromatography repeated in duplicate. Liver biopsy samples were fixed in 10% formaldehyde, and liver fibrosis was graded using the modified histological activity index Knodell score (F0-F4). Correlations among histologic grading, LSM, and MEGX measures were analyzed with the Pearson linear correlation coefficient. RESULTS: At 24 wk liver fibrosis histologic grading was as follows: F0, n = 2 (control); F1, n = 0; F2, n = 3; F3, n = 7; and F4, n = 2. SWE LSM was positively correlated with histologic grading (r = 0.835, P < 0.001). Specifically, the F4 group had a significantly higher elastic modulus than the F3, F2, and F0 groups (P = 0.002, P = 0.003, and P = 0.006, respectively), and the F3 group also had a significantly higher modulus than the control F0 group (P = 0.039). LSM was negatively associated with plasma MEGX concentrations at 30 min (r = -0.642; P = 0.013) and 60 min (r = -0.651; P = 0.012), time to ½ of the maximum concentration (r = -0.538; P = 0.047), and the area under the curve (r = -0.636; P = 0.014). Multiple comparisons showed identical differences in these three measures: significantly lower with F4 (P = 0.037) and F3 (P = 0.032) as compared to F0 and significantly lower with F4 as compared to F2 (P = 0.032). CONCLUSION: SWE LSM shows a good correlation with histologic fibrosis grading and pharmacologic quantitative liver function reserve in experimental severe fibrosis and cirrhosis.     

实时剪切波弹性成像检测的肝脏硬度与食管静脉曲张程度的相关性

目的 应用实时剪切波弹性成像测量慢性乙型肝炎重度及肝硬化患者的肝脏硬度(LS),探讨其评价患者食管静脉曲张(EV)的存在及其严重程度的价值. 方法 根据胃镜结果将256例慢性乙型肝炎重度及肝硬化患者分为无EV组、轻度EV组、中-重度EV组,分析各组患者的LS、门静脉内径(PV)、脾静脉内径(SV)、肝纤维化指标与EV程度的相关性.计数资料采用x2检验;计量资料三组间均数比较采用单因素方差分析,多重比较采用LSD检验;相关性分析采用双变量Pearson法线性相关分析;用受试者工作特征(ROC)曲线和ROC曲线下面积来评价各项指标的预测能力. 结果 LS、PV、SV在三组间两两比较的差异均有统计学意义(F值分别为137.86,44.77,73.88,P值均＜0.01);患者年龄、Ⅳ型胶原(Ⅳ-C)、层黏连蛋白(LN)和透明质酸(HA)在无EV组和轻度EV组间的差异无统计学意义(P值均＞0.05),而其余组两两比较的差异有统计学意义(P值均＜ 0.05);患者性别、Ⅲ型前胶原N端肽(PCⅢNP)在三组间比较的差异均无统计学意义(P值均＞ 0.05).EV程度与LS、PV、SV、Ⅳ-C、LN、HA呈显著正相关(P值均＜0.01),且LS与EV程度相关性最高(r=0.689,P＜0.01).PCⅢNP与EV程度不相关(P＞0.05).LS曲线下面积为0.923,其预测EV程度的能力比PV、SV、LN、Ⅳ-C、HA、PCⅢNP强,当LS＞7.55 kPa时,诊断轻度EV的敏感度为90.5％,特异度为60％;LS＞18.85kPa时,诊断中-重度EV的敏感度为82.4％,特异度为90.5％. 结论 实时剪切波弹性成像测量LS是预测肝病患者EV的存在及其严重程度的有效检查,可作为评价肝硬化患者EV初始筛查的非侵入性检查方法.     

桡神经浅支端侧吻合修复尺神经高位损伤的研究

目的通过动物实验探讨感觉神经移位一期联合修复尺神经高位（肘关节以上）损伤,手内在肌组织学变化及吻合口神经病理学变化。方法选用成年雄性猕猴6只,以上肢为研究单位,6只动物双侧上肢随机分为3组,每组4侧上肢。 A组（实验组）：于上臂上段切断尺神经,再重新端端吻合。于远端切断桡神经浅支,移位于腕部与尺神经（外膜开窗）作端侧吻合。 B组（对照组）：于上臂上段切除尺神经3 cm,两断端分别折叠结扎,腕部处理同A组。 C组（对照组）：上臂部尺神经处理同A组,腕部不作神经移位。观察术后猴尺神经所支配的手内在肌萎缩程度。取术后1个月、3个月、6个月、12个月猴尺神经支配的手内在肌端侧吻合口、端侧吻合口以远的神经干及小鱼际肌组织,做成切片,光镜下观察其显微结构的变化。结果术后12个月观察到A组雄猴手内在肌恢复自主活动,术侧手内在肌肌肉萎缩不明显;B组术侧手内在肌肌肉萎缩,程度较C组轻;C组术侧手内在肌肌肉明显萎缩。组织学观察结果显示,术后A组神经纤维数量、密度随时间延长而逐渐增加。 B组术后神经纤维数量、密度达到一定数值后无明显变化,但未见肌肉出现变性坏死现象。 C组神经纤维数量明显减少,肌纤维数量亦明显减少,最终大部分肌纤维萎缩伴玻璃样变,间质出血,肉芽组织形成。结论感觉神经移位能有效防止手内在肌萎缩、变性、纤维化,为高位损伤修复后的尺神经的再生、长入创造了良好条件。     

Utility of point shear wave elastography in characterisation of focal liver lesions

Background: The present study aimed at evaluation of the usefulness of point shear wave elastography (pSWE) in characterization of FLL(s) by quantifying their stiffness.

Methods: In total, 197 patients (mean age was 56.57 years) with FLL(s) on conventional ultrasound were included. Final diagnoses, confirmed by imaging and/or biopsy whenever possible, included hepatocellular carcinoma (HCC) (n = 143), metastasis (n = 36), hemangioma (n = 16), and focal nodular hyperplasia (n = 2). Stiffness evaluation was performed by pSWE. Stiffness ratio (lesion to background liver) was calculated. ROC analysis was performed to evaluate the diagnostic accuracy of the stiffness value and stiffness ratio and to extract the optimal cutoff values for characterisation of FLL(s).

Results: HCC was significantly softer than its surrounding liver parenchyma [5.43 (3.03) vs. 17.05 (8.53) kPa, p <0.001]. However, the stiffness values for the other examined FLLs were comparable to their surrounding liver parenchyma. No significant difference was detected across different types of metastases or between metastases and surrounding liver (p>0.05). Stiffness ratio was superior to stiffness value in discrimination of HCC from metastasis (AUROC, 0.91 vs. 0.51 respectively).

Conclusion: pSWE could provide a complementary information about FLLs especially in differentiation between HCCs from metastases.     

An initial trial of quantitative evaluation of autoimmune pancreatitis using shear wave elastography and shear wave dispersion in transabdominal ultrasound

Background/ObjectivesWe aimed to examine therapeutic efficacy and prognosis prediction of autoimmune pancreatitis (AIP) using shear wave elastography (SWE) and shear wave dispersion (SWD) in transabdominal ultrasound (US).MethodsThe subjects were 23 patients with diffuse type 1 AIP who underwent SWE and SWD, and 34 controls with a normal pancreas. Elasticity and dispersion were defined as the pancreatic elastic modulus (PEM) and dispersion slope, respectively. PEM and dispersion slope were compared between AIP and control cases, and the short-term therapeutic effect and long-term prognosis were examined.ResultsPEM (30.9 vs. 6.6 kPa, P < 0.001) and dispersion slope (15.3 vs. 13.0 (m/sec)/kHz, P = 0.011) were significantly higher in AIP cases than in controls. Among the 17 AIP patients followed-up in two weeks after treatment, these parameters were 12.7 kPa and 10.5 (m/sec)/kHz with median decrease rate of 37.2% and 32.8%, respectively, which were significantly higher than the change in the size of pancreatic parenchyma (14.4%, P = 0.026). Fourteen of these subjects were followed up for >12 months, during which 2 had relapse; diabetes improved in 5 and worsened in 2; in 60% of cases, the pancreatic parenchyma was atrophied. The % change in PEM after two weeks was tended to be higher in non-atrophy cases.ConclusionSWE and SWD measurement in US may be useful for quantitative assessment of AIP and evaluation of short-term treatment efficacy.     

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.