BACKGROUND & AIMS: :Vti proteins are conserved from yeast to humans and regulate intracellular membrane trafficking by providing one specific SNARE domain, the Qb SNARE, to the four helical SNARE bundle that drives membrane fusion. Two mammalian Vti genes, Vti1a and Vti1b are reported to regulate distinct aspects of endolysosomal trafficking and retrograde transport to the Golgi, but have also been implicated in synaptic vesicle secretion. In this review, we summarize the current evidence for the role of Vti proteins in intracellular trafficking in different cells. We propose that, despite some unique aspects, the two mammalian VTI genes have largely redundant functions in neurosecretory cells and recycle molecules required for the sorting of regulated cargo to the Golgi. Defects in this recycling also lead to defects in synaptic transmission and dense core vesicle secretion.

背景与目标： : Vti蛋白从酵母到人类是保守的，并通过向驱动膜融合的四个螺旋圈套器束提供一个特定的圈套器结构域Qb圈套器来调节细胞内膜的运输。据报道，两个哺乳动物Vti基因Vti1a和Vti1b调节内溶体运输和逆行转运到高尔基体的不同方面，但也与突触小泡分泌有关。在这篇综述中，我们总结了Vti蛋白在不同细胞中细胞内运输中的作用的最新证据。我们建议，尽管有一些独特的方面，但两个哺乳动物VTI基因在神经分泌细胞中具有很大程度上的冗余功能，并回收将受调节的货物分选到高尔基体所需的分子。这种回收的缺陷也导致突触传递和密集的核心囊泡分泌的缺陷。

BACKGROUND & AIMS: :Electric field modulation of magnetic properties via magnetoelectric coupling in composite materials is of fundamental and technological importance for realizing tunable energy efficient electronics. Here we provide foundational analysis on magnetoelectric voltage tunable inductor (VTI) that exhibits extremely large inductance tunability of up to 1150% under moderate electric fields. This field dependence of inductance arises from the change of permeability, which correlates with the stress dependence of magnetic anisotropy. Through combination of analytical models that were validated by experimental results, comprehensive understanding of various anisotropies on the tunability of VTI is provided. Results indicate that inclusion of magnetic materials with low magnetocrystalline anisotropy is one of the most effective ways to achieve high VTI tunability. This study opens pathway towards design of tunable circuit components that exhibit field-dependent electronic behavior.

背景与目标： : 通过复合材料中的磁电耦合对磁性能的电场调制对于实现可调谐的节能电子设备具有基本和技术重要性。在这里，我们提供了磁电电压可调谐电感器 (VTI) 的基础分析，该电感器在中等电场下表现出高达1150% 的极大电感可调谐性。电感的这种场依赖性是由磁导率的变化引起的，磁导率与磁各向异性的应力依赖性相关。通过结合实验结果验证的分析模型，可以全面了解VTI可调性的各种各向异性。结果表明，包含低磁晶各向异性的磁性材料是实现高VTI可调性的最有效方法之一。这项研究为设计表现出场相关电子行为的可调电路组件开辟了道路。

BACKGROUND & AIMS: :The Arabidopsis genome contains a family of v-SNAREs: VTI11, VTI12, and VTI13. Only VTI11 and VTI12 are expressed at appreciable levels. Although these two proteins are 60% identical, they complement different transport pathways when expressed in the yeast vti1 mutant. VTI11 was identified recently as the mutated gene in the shoot gravitropic mutant zig. Here, we show that the vti11 zig mutant has defects in vascular patterning and auxin transport. An Arabidopsis T-DNA insertion mutant, vti12, had a normal phenotype under nutrient-rich growth conditions. However, under nutrient-poor conditions, vti12 showed an accelerated senescence phenotype, suggesting that VTI12 may play a role in the plant autophagy pathway. VTI11 and VTI12 also were able to substitute for each other in their respective SNARE complexes, and a double-mutant cross between zig and vti12 was embryo lethal. These results suggest that some VTI1 protein was necessary for plant viability and that the two proteins were partially functionally redundant.

背景与目标： : 拟南芥基因组包含一个v-SNAREs家族: VTI11，VTI12和vti13。只有VTI11和VTI12以可观的水平表示。尽管这两种蛋白质60% 相同，但是当在酵母vti1突变体中表达时，它们补充不同的转运途径。VTI11最近被鉴定为芽引力突变体zig中的突变基因。在这里，我们表明vti11 zig突变体在血管模式和生长素转运方面存在缺陷。拟南芥t-dna插入突变体vti12在营养丰富的生长条件下具有正常的表型。然而，在营养不足的条件下，vti12表现出加速的衰老表型，表明VTI12可能在植物自噬途径中起作用。VTI11和VTI12也能够在各自的圈套复合物中相互替代，zig和vti12之间的双突变杂交是胚胎致死的。这些结果表明，某些VTI1蛋白是植物生存所必需的，并且这两种蛋白在功能上是部分冗余的。

BACKGROUND & AIMS: :To develop a risk model for predicting axillary lymph node metastasis (LNM) in patients with breast invasive ductal carcinoma (IDCs) using ultrasound (US), US elastography of virtual touch tissue imaging (VTI) and virtual touch tissue imaging & quantification (VTIQ), and histologic parameters. This study included 162 breast IDCs in 162 patients. Univariate and multivariate analyses were used to identify the risk factors and a risk model was created. The results found that 64 (39.5%) of 162 patients had axillary LNMs. The risk score (RS) for axillary LNM was defined as following: RS = 1.3 × (if lesion size ≥20 mm) + 2.6 × (if taller than wide shape) + 2.2 × (if VTI score ≥5) + 3.9 × (if histological grade III) + 1.9 × (if positive C-erbB-2). The rating system was divided into 6 stages (i.e. Stage I, Stage II, Stage III, Stage IV, Stage V, and Stage VI) and the associated risk rates in terms of axillary LNM were 0% (0/19), 6.1% (2/33), 7.7% (3/39), 65.5% (19/29), 92.3% (24/26), and 100% (16/16), respectively. The risk model for axillary LNM established in the study may facilitate subsequent treatment planning and management in patients with breast IDCs.

背景与目标： : 使用超声 (US)，虚拟触摸组织成像 (VTI) 和虚拟触摸组织成像与量化 (VTIQ) 的US弹性成像技术开发预测乳腺浸润性导管癌 (IDCs) 患者腋窝淋巴结转移 (LNM) 的风险模型)，以及组织学参数。这项研究包括162例患者的162例乳腺idc。使用单变量和多变量分析来识别风险因素，并创建了风险模型。结果发现162例患者中有64例 (39.5% 例) 患有腋窝LNMs。腋窝LNM的风险评分 (RS) 定义如下: RS  =   1.3  ×   (若病灶大小 ≥ 20 mm)  +   2.6  ×   (若高于宽形)   +   2.2  ×   (若VTI评分 ≥ 5)  +   3.9  ×   (若组织学分级为III级)   +   1.9  ×   (若C-erbB-2阳性)。评级系统分为6个阶段 (即第一阶段、第二阶段、第三阶段、第四阶段、第五阶段和第六阶段)，腋窝LNM的相关风险率为0% (0/19) 、6.1% (2/33) 、7.7% (3/39)，分别为65.5% (19/29) 、92.3% (24/26) 和100% (16/16)。研究中建立的腋窝LNM风险模型可能有助于乳腺癌患者的后续治疗计划和管理。

BACKGROUND & AIMS: BACKGROUND:Haemodynamic and functional effects of cardiac resynchronization therapy (CRT) have been studied mostly at rest. CRT effects on left ventricular (LV) dyssynchrony and function during stress have not been evaluated in detail. AIMS:We studied the electromechanical effects of CRT at rest and during Dobutamine stress echocardiography (DSE), during active and withheld CRT. METHODS:Twenty-one responders to CRT (62+/-12 yr) were assessed by walking test, quality of life, and BNP with active CRT ("on") and 2 weeks after pacing withdrawal ("off"). DSE (10 microg/kg/min) was performed both at "on" and "off" to evaluate dyssynchrony parameters, systolic and diastolic function. RESULTS:At rest, CRT withdrawal was associated with an increased interventricular mechanical delay (IVMD, from 21+/-18 ms to 49+/-24 ms, p<0.001) and impaired intraventricular synchrony. There was a significant decrease in LV systolic function and LV filling time. Dobutamine infusion had no impact on inter- and intraventricular synchrony. During stress, there was an improvement in LV performance both at "on" and "off". However, LV dp/dt, aortic VTI, cardiac output, mean systolic peak velocities and LV filling time during dobutamine stress were significantly greater with CRT "on". CONCLUSION:In long-term responders, CRT improves LV performance both at rest and during dobutamine stress. This is attributable to an improvement in LV synchrony, which is maintained during stress.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:In studies showing benefits of cardiac resynchronization therapy (CRT), individual atrioventricular (AV) delays have been optimized using echocardiography. However, the method for AV delay optimization remains controversial. METHODS:In 100 consecutive patients with CRT device implantation, AV delay was optimized using echocardiography. The optimal AV delay was determined by changing the interval in 20-ms increments while measuring displacement in 6 basal left ventricular segments (averaged and reported as left ventricular displacement [D(LV)]) and other echocardiographic measures. RESULTS:A single optimal AV delay existed for each patient, and the associated highest D(LV) corresponded with the maximal velocity-time integral (VTI) in the left ventricular outflow tract (VTI(LVOT)) and the E/e' ratio. Significant increases in D(LV) and the VTI(LVOT) from before to after implantation with standard settings and from standard to optimal AV delay by displacement were found. Diastolic filling time corresponded poorly with D(LV) and the VTI(LVOT). CONCLUSION:Individual optimal AV delay programming provides significant improvement in left ventricular performance and hemodynamics. Displacement analysis and the VTI(LVOT) are interchangeable, whereas diastolic filling time cannot be recommended.

背景与目标：

BACKGROUND & AIMS: :Exocytosis involves membrane fusion between secretory vesicles and the plasma membrane. The Soluble N-ethylmaleimide-sensitive factor attachment proteins (SNAPs) and their receptor proteins (SNAREs) interact to fuse vesicles with the membrane and trigger the release of their sialosecretome out of the tick salivary gland cells. In this study, we examined the functional significance of the Vti family of SNARE proteins of blood-feeding Amblyomma maculatum and Amblyomma americanum. Vti1A and Vti1B have been implicated in multiple functional roles in vesicle transport. QRT-PCR studies demonstrated that the highest transcriptional expression of vti1a and vti1b genes occurs in unfed salivary glands, suggesting that elevated secretory vesicle formation occurs prior to feeding but continues at low rates after blood feeding commences. Vti1A and Vti1B localize to the secretory vesicles in unfed tick salivary glands in immunofluorescence microscopy studies. Knockdown of vti1a and vti1b by RNA interference resulted in a significant decrease in the engorged tick weight compared to the control during prolonged blood-feeding on the host. RNA interference of vti1a or vti1b impaired oviposition and none of the ticks produced eggs masses. Surprisingly, the double knockdown did not produce a strong phenotype and ticks fed normally on the host and produced egg masses, suggesting a compensatory mechanism exists within the secretory system which may have been activated in the double knockdown. These results suggest an important functional role of the Vti family of SNARE proteins in tick blood feeding and ultimately oviposition. Understanding the basic functions of the Vti family of SNARE proteins in salivary glands may lead to better ways to prevent tick attachment and transmission of tick-borne diseases.

背景与目标： : 胞吐作用涉及分泌囊泡和质膜之间的膜融合。可溶性N-乙基马来酰亚胺敏感因子附着蛋白 (SNAPs) 及其受体蛋白 (SNAREs) 相互作用，将囊泡与膜融合，并触发其唾液腺细胞释放出唾液腺细胞。在这项研究中，我们检查了血液喂养的黄斑弱小和美洲弱小的snal蛋白的Vti家族的功能意义。Vti1A和Vti1B在囊泡转运中具有多种功能作用。QRT-PCR研究表明，vti1a和vti1b基因的最高转录表达发生在未进食的唾液腺中，这表明分泌囊泡的形成在进食之前发生，但在开始进食后以较低的速率持续。在免疫荧光显微镜研究中，Vti1A和Vti1B定位于未进食的tick唾液腺的分泌囊泡。与对照组相比，通过RNA干扰敲除vti1a和vti1b导致在宿主上长时间采血期间，饱食的tick虫重量显着降低。vti1a或vti1b的RNA干扰损害了产卵，并且没有一个tick产生卵团。令人惊讶的是，双重敲低并没有产生强烈的表型，而蜱通常在宿主上喂食并产生卵团，这表明分泌系统中存在一种补偿机制，该机制可能已在双重敲低中被激活。这些结果表明，snal蛋白的Vti家族在tick血液喂养和最终产卵中具有重要的功能作用。了解唾液腺中snal蛋白Vti家族的基本功能可能会导致更好的方法来预防tick附着和tick传播疾病的传播。

BACKGROUND & AIMS: BACKGROUND:Ischemia-reperfusion injury results in conduit vessel endothelial dysfunction as assessed by flow-mediated dilatation (FMD). The effect on the potentially more important microvascular circulation has not been well studied. The objective of our study was to assess the effect of ischemia-reperfusion injury on microvascular function including peripheral arterial tonometry (PAT) hyperemic index. METHODS:45 healthy volunteers free of cardiovascular disease were recruited (mean age 35 ± 14 yrs, 29 men). Using ultrasound, the flow-mediated dilation (FMD) and hyperemic velocity (VTI) of the brachial artery were measured following a 5-minute forearm cuff occlusion. Simultaneously, the PAT hyperemic index was measured. Ischemia was then induced by a 15-minute upper arm occlusion and within 15 minutes of recovery the vascular measures were repeated. RESULTS:Ischemia caused a significant reduction in FMD (7.9 ± 4.0 to 4.7 ± 3.5, p = 0.0001). The hyperemic VTI, a measure of microvascular function, was unaffected following ischemia-reperfusion (92 ± 30 vs. 97 ± 37 cm, p = 0.236). Finally, PAT index was also unchanged by the intervention (2.07 ± 0.8 vs. 2.04 ± 0.7, p = 0.742). CONCLUSIONS AND DISCUSSIONS:Ischemia-reperfusion caused conduit and not resistance vessel endothelial dysfunction. The PAT-index was unchanged suggesting that this measure is more closely aligned with resistance than conduit vessel function. This has implications for its use as a measure of vascular function in clinical research.

背景与目标：

BACKGROUND & AIMS: AIMS:It has been shown that optimizing atrioventricular (AV) and interventricular (VV) delay improves cardiac performance in patients with biventricular pacemakers. However, there is no standard method for optimization available yet. The aim of this study was to compare echocardiographic parameters-displacement imaging, A wave duration, and aortic velocity time integral (VTI)-and acoustic cardiography derived electromechanical activation time (EMAT) using different approaches of AV and VV delay optimization. We tested whether the initial optimization of the AV interval followed by VV optimization at that optimal AV interval or initial optimization of the VV interval followed by AV optimization at the determined optimal VV interval was accurate and consistent, and how this compared to testing every conceivable combination of AV and VV intervals available. METHODS AND RESULTS:A group of 20 patients with biventricular pacemakers was included. Displacement imaging, A wave duration, and aortic VTI were determined at different combinations of AV (100, 150, 200, 250 ms) and VV (RV40, 0, LV40 ms) intervals. If AV duration was determined first, displacement imaging identified the best setting in 8/20, aortic VTI in 10/20, A duration in 13/20, and EMAT in 18/20 patients. With VV duration determined first, the best setting was more difficult to identify regardless of the method used. There was a poor agreement in optimal AV and VV delays of the different methods, and there was no single patient in whom all four methods yielded the same delay combination. CONCLUSION:It is advisable to measure a full grid of AV and VV delays to identify optimal settings rather than optimizing one of the two delays first. Different techniques for delay optimization resulted in different optimal delay combinations.

背景与目标：

BACKGROUND & AIMS: Study hypothesis:We sought to investigate the association between echocardiographic optimisation and ventricular activation time in cardiac resynchronisation therapy (CRT) patients, obtained through the use of electrocardiographic mapping (ECM). We hypothesised that echocardiographic optimisation of the pacing delay between the atrial and ventricular leads-atrioventricular delay (AVD)-and the delay between ventricular leads-interventricular pacing interval (VVD)-would correlate with reductions in ventricular activation time. Background:Optimisation of AVD and VVD may improve CRT patient outcome. Optimal delays are currently set based on echocardiographic indices; however, acute studies have found that reductions in bulk ventricular activation time correlate with improvements in acute haemodynamic performance. Materials and methods:Twenty-one patients with established CRT criteria were recruited. After implantation, patients underwent echo-guided optimisation of the AVD and VVD. During this procedure, the participants also underwent noninvasive ECM. ECM maps were constructed for each AVD and VVD. ECM maps were analysed offline. Total ventricular activation time (TVaT) and a ventricular activation time index (VaT10-90) were calculated to identify the optimal AVD and VVD timings that gave the minimal TVaT and VaT10-90 values. We correlated cardiac output with these electrical timings. Results:Echocardiographic programming optimisation was not associated with the greatest reductions in biventricular activation time (VaT10-90 and TVaT). Instead, bulk activation times were reduced by a further 20% when optimised with ECM. A significant inverse correlation was identified between reductions in bulk ventricular activation time and improvements in LVOT VTI (p < 0.001), suggesting that improved ventricular haemodynamics are a sequelae of more rapid ventricular activation. Conclusions:EAM-guided programming optimisation may achieve superior fusion of activation wave fronts leading to improvements in CRT response.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:Point-of-care transthoracic echocardiography (POC-TTE) is essential in shock management, allowing for stroke volume (SV) and cardiac output (CO) estimation using left ventricular outflow tract diameter (LVOTD) and left ventricular velocity time integral (VTI). Since LVOTD is difficult to obtain and error-prone, the body surface area (BSA) or a modified BSA (mBSA) is sometimes used as a surrogate (LVOTDBSA, LVOTDmBSA). Currently, no models of LVOTD based on patient characteristics exist nor have BSA-based alternatives been validated. METHODS:Focused rapid echocardiographic evaluations (FREEs) performed in intensive care unit patients over a 3-year period were reviewed. The age, sex, height, and weight were recorded. Human expert measurement of LVOTD (LVOTDHEM) was performed. An epsilon-support vector regression was used to derive a computer model of the predicted LVOTD (LVOTDCM). Training, testing, and validation were completed. Pearson coefficient and Bland-Altman were used to assess correlation and agreement. RESULTS:Two hundred eighty-seven TTEs with ideal images of the LVOT were identified. LVOTDCM was the best method of SV measurement, with a correlation of 0.87. LVOTDmBSA and LVOTDBSA had correlations of 0.71 and 0.49 respectively. Root mean square error for LVOTDCM, LVOTDmBSA, and LVOTDBSA respectively were 13.3, 37.0, and 26.4. Bland-Altman for LVOTDCM demonstrated a bias of 5.2. LVOTDCM model was used in a separate validation set of 116 ideal images yielding a linear correlation of 0.83 between SVHEM and SVCM. Bland Altman analysis for SVCM had a bias of 2.3 with limits of agreement (LOAs) of - 24 and 29, a percent error (PE) of 34% and a root mean square error (RMSE) of 13.9. CONCLUSIONS:A computer model may allow for SV and CO measurement when the LVOTD cannot be assessed. Further study is needed to assess the accuracy of the model in various patient populations and in comparison to the gold standard pulmonary artery catheter. The LVOTDCM is more accurate with less error compared to BSA-based methods, however there is still a percentage error of 33%. BSA should not be used as a surrogate measure of LVOTD. Once validated and improved this model may improve feasibility and allow hemodynamic monitoring via POC-TTE once it is validated.

背景与目标：

BACKGROUND & AIMS: Fifty patients with rheumatic mitral stenosis aged twelve to thirty-six (twenty +/- six) years were studied by two-dimensional, pulsed and color Doppler echocardiography during, seventy-two hours after, and biweekly for three months after balloon mitral valvuloplasty (BMV). Transesophageal echocardiography (TEE) done immediately after BMV (in the catheterization laboratory) detected a new atrial septal defect (ASD) in 46 (92%) patients. These measured 1 to 2 (mean 1.2 +/- 0.3) mm in diameter. Doppler color flow mapping guided the location of the ASD in most of the cases. A narrow jet of left-to-right shunt could be evaluated by pulsed Doppler studies. Velocity time integral (VTI) of the jet across one cardiac cycle and the diameter of the ASD were used to calculate the left-to-right shunt (shunt = VTI x pi (D/2)2 x heart rate). The estimated shunt was 0.04-0.39 (mean 0.20 +/- 0.10) L/minute. A repeat study at seventy-two hours revealed the defect in 40 (80%) patients. At three months, the defect persisted in only 5 (10%) cases. The mean interval of closure of ASD was 4.6 +/- 2.2 weeks. The authors conclude(1) ASD occurs commonly after BMV, (2) the septal defect and the resultant left-to-right shunt are insignificant, and (3) ASD disappears in the majority of cases by three months after BMV.

背景与目标： 通过二维，脉冲和彩色多普勒超声心动图对50例12至36岁 (二尖瓣狭窄) 的二尖瓣狭窄患者进行了研究。球囊二尖瓣成形术 (BMV)。BMV (在导管实验室) 后立即进行经食管超声心动图 (TEE) 在46 (92%) 例患者中发现了新的房间隔缺损 (ASD)。这些测量的直径为1至2 (平均1.2 +/- 0.3) mm。在大多数情况下，多普勒彩色血流图可指导ASD的位置。可以通过脉冲多普勒研究来评估从左向右分流的窄射流。在一个心动周期内射流的速度时间积分 (VTI) 和ASD的直径用于计算从左向右分流 (分流 = VTI x pi (D/2)2 x心率)。估计分流为0.04-0.39 (平均0.20 +/- 0.10) L/分钟。72小时的重复研究揭示了40 (80%) 名患者的缺陷。在三个月时，缺陷仅在5 (10%) 例中持续存在。ASD的平均闭合间隔为4.6 +/- 2.2周。作者得出的结论是 :( 1) BMV后ASD通常发生; (2) 间隔缺损和由此产生的左右分流无关紧要; (3) 在BMV后三个月内，大多数情况下ASD消失。

BACKGROUND & AIMS: BACKGROUND:The assessment of hemodynamics in patients supported with left ventricular assist devices (LVADs) is often challenging. Physical examination maneuvers correlate poorly with true hemodynamics. We assessed the value of novel transthoracic echocardiography (TTE)-derived variables to reliably predict hemodynamics in patients supported with LVAD. METHODS AND RESULTS:A total of 102 Doppler-TTE images of the LVAD outflow cannula were obtained during simultaneous invasive right heart catheterization (RHC) in 30 patients supported with continuous-flow LVADs (22 HMII, 8 HVAD) either during routine RHC or during invasive ramp testing. Properties of the Doppler signal though the outflow cannula were measured at each ramp stage (RS), including the systolic slope (SS), diastolic slope (DS), and velocity time integral (VTI). Hemodynamic variables were concurrently recorded, including Doppler opening pressure (MAP), heart rate (HR), right atrial pressure, pulmonary artery pressure, pulmonary capillary wedge pressure (PCWP), Fick cardiac output (CO) and systemic vascular resistance (SVR). Univariate and multivariate regression analyses were used to explore the dependence of PCWP, CO, and SVR on DS, SS, VTI, MAP, HR, and RS. Multivariate linear regression analysis revealed significant contributions of DS on PCWP (PCWPpred = 0.164DS + 4.959; R = 0.68). Receiver operating characteristic (ROC) curve analysis revealed that PCWPpred could predict an elevated PCWP ≥18 mm Hg with a sensitivity (Sn) of 94% and specificity (Sp) of 85% (area under the ROC curve 0.88). CO could be predicted by RS, VTI, and HR (COpred = 0.017VTI + 0.016HR + 0.12RS + 2.042; R = 0.61). COpred could predict CO ≤4.5 L/min with Sn 73% and Sp 79% (AUC 0.81). SVR could be predicted by MAP, VTI, and HR (SVRpred = 15.44MAP - 5.453VTI - 6.349HR + 856.15; R = 0.84) with Sn 84% and Sp 79% (AUC 0.91) to predict SVR ≥1200 dyn-s/cm5. CONCLUSIONS:Doppler-TTE variables derived from the LVAD outflow cannula can reliably predict PCWP, CO, and SVR in patients supported with LVADs and may mitigate the need for invasive testing.

背景与目标：

BACKGROUND & AIMS: :The goal of our study was to investigate the value of color-coded Virtual Touch tissue imaging (VTI) using acoustic radiation force impulse (ARFI) technology in the characterization of breast lesions and to compare it with conventional ultrasound (US). Conventional US and color-coded VTI were performed in 196 solid breast lesions in 196 consecutive women (age range 17-91 y; mean 48.17 ± 14.46 y). A four-point scale VTI score was assigned for each lesion according to the color pattern both in the lesion and in the surrounding breast tissue. The mean VTI score was significantly higher for malignant lesions (3.80 ± 0.66, range 1-4) than for benign ones (2.02 ± 1.20, range 1-4) (p < 0.001), and the optimal cut-off value was between score 3 and score 4. The area under the receiver operating characteristic (ROC) curve for combined conventional US and VTI (0.945) was significantly higher than that for conventional US (0.902) and for VTI (0.871) (p = 0.0021 and p < 0.001, respectively). It was concluded that color-coded VTI with the proposed four-point scale score system combined with conventional US might have the potential to aid in the characterization of benign and malignant breast lesions.

背景与目标： : 我们研究的目的是研究使用声辐射力冲动 (ARFI) 技术的彩色编码虚拟触摸组织成像 (VTI) 在乳腺病变特征中的价值，并将其与常规超声 (US) 进行比较。在连续196名女性 (年龄范围17-91岁; 平均48.17 ± 14.46岁) 的196个乳腺实体病变中进行了常规US和颜色编码的VTI。根据病变和周围乳腺组织中的颜色模式，为每个病变分配四点VTI评分。恶性病变的平均VTI评分 (3.80 ± 0.66，范围1-4) 明显高于良性病变 (2.02 ± 1.20，范围1-4) (p <0.001)，最佳临界值介于3分和4分之间。组合常规US和VTI (0.945) 的接收器工作特性 (ROC) 曲线下的面积显著高于常规US (0.902) 和VTI (0.871) (分别为p = 0.0021和p <0.001)。结论是，将颜色编码的VTI与拟议的四点量表评分系统结合使用常规US可能具有帮助表征良性和恶性乳腺病变的潜力。

BACKGROUND & AIMS: INTRODUCTION/OBJECTIVE:This study consist of an experiment comparing acoustic characteristics of vowel production among females. The aim of this investigation was to explore the stability among vowels with quantification of acoustic changes in the voice related to speech production associated with an ample variety of vowel sounds. An additional goal was to establish a systematic control of variables and standardization of the data collection procedures. METHODS:All data were collected in a quiet environment using the Computerized Speech Lab (CSL; Kay Elemetrics, Montvale, NJ), a computer-based system designed to measure characteristics of voice. Jitter and shimmer, measures of perturbation that reflect characteristics of voice, were applied. Two additional acoustic measures were examined: (1) noise-to-harmonic ratio (NHR), a general evaluation of presence of noise in the voice signal; and (2) voice turbulence index (VTI), related to turbulence caused by abnormal adduction of vocal folds. A systematic methodology of data collection was organized, in an effort to establish a research protocol based on relevant literature, involving (1) keeping constant fundamental frequency (F0) and intensity, (2) positioning of participants and recording equipment, and (3) environmental noise. RESULTS AND CONCLUSION:When measured acoustic parameters of vowels were compared, results revealed that the vowel sounds had a significant effect on shimmer and VTI. Furthermore, speech sounds classified as back vowels exhibited less perturbation and noise in the acoustic signal: the high-back vowels [u] and []; and the mid-back vowels [o] and [], demonstrated most of the statistically significant reduced values of shimmer and VTI among the 12 vowels compared. Further comparisons among front and back vowels grouped in clusters associated to more and less variability led to statistically significant differences in shimmer, NHR, and VTI. Overall, speech sounds classified as back vowels exhibited less variability and noise. Based on the results of this study, back vowels of the English language should be used in voice acoustic tasks in females, given the higher stability of their acoustic signal, as compared with other vowels tested.

背景与目标：