剪切波弹性成像评估米非司酮宫颈软化效果

目的探讨应用剪切波弹性成像技术（SWE）评估米非司酮无痛人流术前宫颈软化效果的可行性。方法选取我院行无痛人流手术的孕妇87例,随机分成试验组43例和对照组44例。试验组术前1 d晚上8时服用米非司酮50mg,对照组不服用药物。应用SWE技术在术前1 d（试验组用药前）及手术当天分别测量宫颈外口前唇及后唇的剪切波速度（SWS）,比较试验组及对照组两次所测SWS的差异,Spearman相关分析手术当天所测宫颈SWS与术中宫颈扩张程度评价的关系。结果试验组术前1 d测得的宫颈前唇及后唇SWS与手术当天测值比较,差异均有统计学意义（均P＜0.05）;对照组术前1 d测得的宫颈前唇及后唇SWS与手术当天测值比较,差异均无统计学意义。相关性分析结果显示,手术当天所测的宫颈前唇SWS与术中宫颈扩张程度评价标准呈正相关（ρ=0.458,P＜0.05）,宫颈后唇SWS与术中宫颈扩张程度无明显相关性（ρ=0.177）。结论应用SWE可检测米非司酮引起的宫颈软化效果,宫颈外口前唇SWS有望作为客观评估宫颈软硬度的指标之一。     

基于SWE技术的弹性异质性分析在校正乳腺病灶BI-RADS分类中的价值

摘要 目的 探讨基于剪切波弹性成像（SWE）技术的弹性异质性分析在校正乳腺病灶BI-RADS分类中的价值 方法 对经病理证实的132例患者共135个乳腺病灶,行BI-RADS分类及SWE检测,测得病灶的弹性模量参数,计算SG（刚度梯度）。以病理结果为金标准,绘制ROC曲线,比较校正前及SG校正后BI-RADS分类区分乳腺良恶性病灶的诊断效能。结果 135个乳腺病灶,良性75个,恶性60个。恶性病灶组各弹性模量参数均高于良性病灶组（P<0.001）,以SG鉴别诊断乳腺病灶良恶性的ROC曲线下面积（AUC）最高,AUC值为0.925,SG的诊断界点值为120.2kPa时,敏感度为88.3%,特异度为96.0%,准确度为92.6%。以BI-RADS 4b为诊断界点,校正前与SG校正后BI-RADS分类鉴别乳腺病灶良恶性的AUC值为0.914、0.964;敏感度为88.3%、90.0%;特异度为82.7%、92.0%;准确度为85.2%、91.1%。结论 基于SWE技术的弹性异质性定量分析在区分乳腺病灶良恶性中具有重要的临床价值,SG校正后BI-RADS分类较常规超声BI-RADS分类提高了诊断性能,可减少不必要的穿刺活检。     

Elasticity standard values of the thoracolumbar fascia assessed with acoustic radiation force impulse elastography on healthy volunteers: A cross section study

IntroductionDetermining the normal values for acoustic radiation force impulse (ARFI) shear wave elastography of the thoracolumbar fascia (TLF) and define possible factors of influence.MethodsWe measured the shear wave velocity (SWV) in m/s and the diameter (anterior-posterior) in mm of the TLF bilateral in 267 healthy participants with the Acuson S3000™ (Siemens) using the virtual touch image quantification mode (VTIQ). The parameters were tested for correlations with the anthropometric data of the participants, between different age groups and the genders, as well as information obtained from the history, such as smoking and sporting activities.ResultsWe determined a mean SWV of 3.28 ± 0.55 m/s for the left thoracolumbar fascia and 3.44 ± 0.55 m/s for the right. The diameter on the right was 2.7 ± 0.8 mm. On the left, it was 2.7 ± 0.9 mm. Neither body mass index (BMI) nor gender had a significant effect on either of the measured parameters (p > 0.05). The same goes for regular medication, sporting activity or the consumption of alcohol (p > 0.05). The results concerning the effect of smoking and age were inconclusive as they only had a significant influence to either the right or the left side of the TLF but not on the other side.ConclusionsWe collected the normal value for ARFI shear wave elastography of the TLF in 267 healthy participants. Furthermore, neither gender, BMI, sports activity nor the consumption of alcohol affected the elasticity or the diameter of the thoracolumbar fascia.     

Efficacy of foam rolling with additional vibration stimulation on the mobility of the thoracolumbar fascia. An observational study

IntroductionObservations show that foam rolling improves joint movements. Likewise, it can be stated that a vibration stimulation of the tissue leads to improved joint mobility.MethodThis study investigates whether the combination of foam rolling and vibrations (31 Hz) can influence the sliding of the thoracolumbar fascia more effectively than normal foam rolling. 45 subjects participated in the study and were divided into a foam roll with additional vibration group (FRV), a foam roll group (FR) and a control group (CG). The intervention groups rolled out the gluteal muscles, the lateral trunk and the upper and lower back. Mobility measures were taken pre and post the respective intervention. Subsequent cross correlation software analysis quantified the sliding of the fascia and calculated its shear strain mobility (SSM).ResultsThe sliding of the thoracolumbar fascia improved significantly within the FRV by 2.83 mm (SD ± 1.08/p < .001), in the FR by 0.96 mm (SD ± 0.43/p < .001) and in the CG decreased the sliding by 0.1401 mm (SD ± 0.28/p = .076). The fascia/fascia SSM increased in the FRV by 22.61% (SD ± 15.64/p < .001), in the FR by 11.41% (SD ± 20.38/p = .056) and in the CG decreased the SSM by 0.9473% (SD ± 11.35/p < .751). The lumbar movement increased in both intervention groups, but showed no significant result.ConclusionThe use of a foam roll with additional vibration and standard intervention have increased thoracolumbar fascia sliding and lumbar movements. The improved shear strain mobility can be attributed to the multi-activity of mechanoreceptors, such as Pacini- and Ruffini-Bodies.     

Shear bond strength of orthodontic brackets to enamel after application of a caries infiltrant

Objective:To examine differences in the shear bond strength of orthodontic brackets on differently mineralized enamel surfaces after applying a caries infiltrant or conventional adhesive.Materials and Methods:A total of 320 bovine incisors were assigned to eight pretreated groups, and the shear force required for debonding was recorded. Residual adhesive was evaluated by light microscopy using the adhesive remnant index. Statistical analysis included Kolmogorov-Smirnov, analysis of variance (ANOVA), and Scheffé tests.Results:The highest bond strength (18.8 ± 4.4 MPa) was obtained after use of the caries infiltrant. More residual adhesive and fewer enamel defects were observed on infiltrated enamel surfaces. Brackets on demineralized enamel produced multiple enamel defects.Conclusions:Acceptable bond strengths were obtained with all material combinations. A caries-infiltrant applied before bracket fixation has a protective effect, especially on demineralized enamel.     

The Role of Viscosity Estimation for Oil-in-gelatin Phantom in Shear Wave Based Ultrasound Elastography

Shear wave based ultrasound elastography utilizes mechanical excitation or acoustic radiation force to induce shear waves in deep tissue. The tissue response is monitored to obtain elasticity information about the tissue. During the past two decades, tissue elasticity has been extensively studied and has been used in clinical disease diagnosis. However, biological soft tissues are viscoelastic in nature. Therefore, they should be simultaneously characterized in terms of elasticity and viscosity. In this study, two shear wave-based elasticity imaging methods, shear wave dispersion ultrasound vibrometry (SDUV) and acoustic radiation force impulsive (ARFI) imaging, were compared. The discrepancy between the measurements obtained by the two methods was analyzed, and the role of viscosity was investigated. To this end, four types of gelatin phantoms containing 0%, 20%, 30% and 40% castor oil were fabricated to mimic different viscosities of soft tissue. For the SDUV method, the shear elasticity μ₁ was 3.90 ± 0.27 kPa, 4.49 ± 0.16 kPa, 2.41 ± 0.33 kPa and 1.31 ± 0.09 kPa; and the shear viscosity μ₂ was 1.82 ± 0.31 Pa•s, 2.41 ± 0.35 Pa•s, 2.65 ± 0.13 Pa•s and 2.89 ± 0.14 Pa•s for 0%, 20%, 30% and 40% oil, respectively in both cases. For the ARFI measurements, the shear elasticity μ was 7.30 ± 0.20 kPa, 8.20 ± 0.31 kPa, 7.42 ± 0.21 kPa and 5.90 ± 0.36 kPa for 0%, 20%, 30% and 40% oil, respectively. The SDUV results demonstrated that the elasticity first increased from 0% to 20% oil and then decreased for the 30% and 40% oil. The viscosity decreased consistently as the concentration of castor oil increased from 0% to 40%. The elasticity measured by ARFI showed the same trend as that of the SDUV but exceeded the results measured by SDUV. To clearly validate the impact of viscosity on the elasticity estimation, an independent measurement of the elasticity and viscosity by dynamic mechanical analysis (DMA) was conducted on these four types of gelatin phantoms and then compared with SDUV and ARFI results. The shear elasticities obtained by DMA (3.44 ± 0.31 kPa, 4.29 ± 0.13 kPa, 2.05 ± 0.29 kPa and 1.06 ± 0.18 kPa for 0%, 20%, 30% and 40% oil, respectively) were lower than those by SDUV, whereas the shear viscosities obtained by DMA (2.52 ± 0.32 Pa·s, 3.18 ± 0.12 Pa·s, 3.98 ± 0.19 Pa·s and 4.90 ± 0.20 Pa·s for 0%, 20%, 30% and 40% oil, respectively) were greater than those obtained by SDUV. However, the DMA results showed that the trend in the elasticity and viscosity data was the same as that obtained from the SDUV and ARFI. The SDUV results demonstrated that adding castor oil changed the viscoelastic properties of the phantoms and resulted in increased dispersion of the shear waves. Viscosity can provide important and independent information about the inner state of the phantoms, in addition to the elasticity. Because the ARFI method ignores the dispersion of the shear waves, namely viscosity, it may bias the estimation of the true elasticity. This study sheds further light on the significance of the viscosity measurements in shear wave based elasticity imaging methods.     

Quantitative Shear Wave Velocity Measurement on Acoustic Radiation Force Impulse Elastography for Differential Diagnosis between Benign and Malignant Thyroid Nodules: A Meta-analysis

The aim of this study was to evaluate the diagnostic performance of quantitative shear wave velocity (SWV) measurement on acoustic radiation force impulse (ARFI) elastography for differentiation between benign and malignant thyroid nodules using meta-analysis. The databases of PubMed and the Web of Science were searched. Studies published in English on assessment of the sensitivity and specificity of ARFI elastography for the differentiation of thyroid nodules were collected. The quantitative measurement of ARFI elastography was evaluated by SWV (m/s). Meta-Disc Version 1.4 software was used to describe and calculate the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and summary receiver operating characteristic curves. We analyzed a total of 13 studies, which included 1,854 thyroid nodules (including 1,339 benign nodules and 515 malignant nodules) from 1,641 patients. The summary sensitivity and specificity for differential diagnosis between benign and malignant thyroid nodules by SWV were 0.81 (95% confidence interval [CI]: 0.77–0.84) and 0.84 (95% CI: 0.81–0.86), respectively. The pooled positive and negative likelihood ratios were 5.21 (95% CI: 3.56–7.62) and 0.23 (95% CI: 0.17–0.32), respectively. The pooled diagnostic odds ratio was 27.53 (95% CI: 14.58–52.01), and the area under the summary receiver operating characteristic curve was 0.91 (Q* = 0.84). In conclusion, SWV measurement on ARFI elastography has high sensitivity and specificity for differential diagnosis between benign and malignant thyroid nodules and can be used in combination with conventional ultrasound.     

Bond strength of self-adhesive resin cements to tooth structure

Objectives

The aim of this study was to evaluate the strength of the bond between newly introduced self-adhesive resin cements and tooth structures (i.e., enamel and dentin).

Methods

Three self-adhesive cements (SmartCem2, RelyX Unicem, seT SDI) were tested. Cylindrical-shaped cement specimens (diameter, 3 mm; height, 3 mm) were bonded to enamel and dentin. Test specimens were incubated at 37 °C for 24 h. The shear bond strength (SBS) was tested in a Zwick Roll testing machine. Results were analyzed by one-way ANOVA and t-test. Statistically significant differences were defined at the α = 0.05 level. Bond failures were categorized as adhesive, cohesive, or mixed.

Results

The SBS values ranged from 3.76 to 6.81 MPa for cements bonded to enamel and from 4.48 to 5.94 MPa for cements bonded to dentin (p > 0.05 between surfaces). There were no statistically significant differences between the SBS values to enamel versus dentin for any given cement type. All cements exhibited adhesive failure at the resin/tooth interface.

Conclusions

Regardless of their clinical simplicity, the self-adhesive resin cements examined in this study exhibit limited bond performance to tooth structures; therefore, these cements must be used with caution.     

实时剪切波弹性成像对甲状腺结节良恶性的诊断及影响因素分析

目的 探讨剪切波弹性成像(SWE)各参数对甲状腺结节良恶性鉴别诊断的临床价值。方法 应用SWE对拟接受手术或活检的221例甲状腺结节患者(265个结节)进行检查,测量结节的绝对弹性值。以病理结果为金标准,绘制ROC曲线,得到最优的诊断界点,并以此进行良恶性诊断。根据ROC曲线下面积评价各个SWE参数的诊断价值。同时,分析可能存在的影响因素。结果 265个甲状腺结节中,良性177个,恶性88个。恶性结节的杨氏模量均高于良性结节,差异有统计学意义(P均<0.05)。5个SWE参数(SWE_whole_mean、SWE_whole_min、SWE_mean、SWE_min、SWE_max)诊断结节良恶性的ROC曲线下面积分别为0.793、0.656、0.801、0.796和0.791。SWE_mean的ROC曲线下面积(AUC)面积最大,以最优的诊断界点为39.2 kPa进行良恶性诊断,诊断的敏感度和特异度分别为67.05% 和83.62%。各可能的影响因素中,结节内钙化会使测量到的杨氏模量值增加。SWE与常规超声联合应用的诊断敏感度为86.36%。结论 SWE有助于甲状腺结节良恶性的鉴别诊断。     

剪切波弹性成像诊断甲状腺结节Meta分析

目的应用Meta分析评价剪切波弹性成像诊断甲状腺结节的价值。方法计算机检索PubMed、Nature、中国期刊全文数据库CNKI和万方等数据库,收集关于甲状腺结节剪切波弹性成像的中英文文献,根据诊断性试验研究的纳入标准纳入和排除文献,应用Meta-Disc1.4软件对纳入的研究结果进行Meta分析并绘制汇总受试者工作特征(SROC)曲线,计算曲线下面积。结果最终纳入5篇文献、共586个甲状腺病灶,病理结果显示良性结节481个,恶性结节105个。剪切波弹性成像诊断甲状腺结节良恶性的敏感度0.84[95%CI(0.75~0.90)],特异度0.86[95%CI(0.83~0.89)],阳性似然比6.35[95%CI(2.64~15.24)],阴性似然比为0.20[95%CI(0.13~0.31)],诊断比值比31.21[95%CI(12.40~78.53)],诊断试验的SROC曲线下面积为0.9037(Q*=0.8353)。结论应用剪切波弹性成像诊断甲状腺结节的敏感度和特异度均较高,能够作为甲状腺结节的无创诊断方法。