Reliability of ultrasound speckle tracking with singular value decomposition for quantifying displacement in the carpal tunnel

Inhibited movement patterns of carpal tunnel structures have been found in carpal tunnel syndrome (CTS) patients. Motion analysis on ultrasound images allows us to non-invasively study the (relative) movement of carpal tunnel structures and recently a speckle tracking method using singular value decomposition (SVD) has been proposed to optimize this tracking. This study aims to assess the reliability of longitudinal speckle tracking with SVD in both healthy volunteers and patients with CTS.Images from sixteen healthy volunteers and twenty-two CTS patients were used. Ultrasound clips of the third superficial flexor tendon and surrounding subsynovial connective tissue (SSCT) were acquired during finger flexion-extension. A custom made tracking algorithm was used for the analysis. Intra-class correlation coefficients (ICCs) were calculated using a single measure, two-way random model with absolute agreement and Bland-Altman plots were added for graphical representation.ICC values varied between 0.73 and 0.95 in the control group and 0.66–0.98 in the CTS patients, with the majority of the results classified as good to excellent. Tendon tracking showed higher reliability values compared to the SSCT, but values between the control and CTS groups were comparable.Speckle tracking with SVD can reliably be used to analyze longitudinal movement of anatomical structures with different sizes and compositions within the context of the carpal tunnel in both a healthy as well as a pathological state. Based on these results, this technique also holds relevant potential for areas where ultrasound based dynamic imaging requires quantification of motion.     

二维斑点追踪技术评价犬心梗后自体骨髓CD34＋干细胞移植对心肌功能的影响

目的应用二维斑点追踪成像超声心动图（2D-STE）,评价犬心梗后自体骨髓CD34＋干细胞移植对心肌功能的影响。方法 12只杂种犬行冠脉左前降支结扎术,导致前壁心肌梗死,随机分为两组,A组为对照组,结扎术后两周二次开胸手术,经心肌注射磷酸盐缓冲液（PBS）1 mL;B组为治疗组,结扎术后两周二次开胸手术,经心肌注射含自体骨髓CD34＋干细胞的磷酸盐缓冲液1 mL。应用STE对12只犬结扎术前、术后左室短轴基底段及心尖段心室节段径向应变（RS）、圆周方向应变（CS）以及局部心肌旋转（Rot）进行分析,并对对照组和治疗组治疗后的RS、CS及Rot变化进行比较。结果心肌梗死后梗死节段的RS、CS以及Rot均下降,治疗后治疗组梗死段RS及Rot较对照组好转。结论 STE能够评价左室短轴局部心肌的收缩功能,心肌梗死后梗死段短轴各方向应变减低,自体骨髓CD34＋干细胞移植能够提高局部心肌的收缩功能。     

基于改进C-V模型的超声心动图像轮廓的提取方法

目的:通过超声图像预处理和对图像分割方法的改进,完成超声心动图中心腔轮廓的提取。方法:首先,运用基于斑点指数的滤波方法对超声图像进行去噪。其次,对超声图像进行分段非线性灰度变换,提高图像对比度。最后,利用改进的基于C-V模型的水平集算法对超声图像进行分割,得到精确的初始轮廓。结果:1基于斑点指数的图像滤波方法可以在不丢失细节的情况下对超声图像进行噪声滤除。2分段非线性灰度变换可以有效提高超声图像的对比度。3改进的C-V模型可以成功的对含有斑点噪声的超声图像进行分割。结论:本文的超声图像预处理方法和分割算法可以有效提取心腔轮廓,降低斑点噪声对图像分割结果的影响。     

斑点追踪技术评价冠状动脉搭桥术后心肌功能的临床价值研究

目的:探讨超声斑点追踪成像技术定量评价冠状动脉搭桥术前、后心肌功能的临床价值。方法:选择2012年1月~2013年1月在我院心脏外科行体外循环下冠状动脉旁路移植术的患者,对冠状动脉搭桥术术前1周、术后1月、3月、6月进行常规超声心动图检查,然后应用斑点追踪技术进行分析。结果:所有患者的纵向应变值仅在术后3个月和6个月显著增加,与术前、术后1个月比较差别有统计学意义(P0.01)。圆周应变值在术后1个月、3个月和6个月均显著增高,与术前比较差别有统计学意义(P0.05)。老年组术后6个月的纵向应变值和圆周应变值与术后3个月比较差别有统计学意义(P0.05)。手术前、后常规超声心动图检查结果比较差别无统计学意义(P0.05)。结论:超声斑点追踪技术用于评估CABG术后缺血心肌的功能变化的敏感性高于常规超声心动图检查,为临床评价CABG的疗效提供了一种新方法。     

斑点追踪技术评价PCI术后左室功能的实验研究

目的:探讨二维斑点成像(speckle tissue imaging,STI)技术在经皮冠状动脉介入治疗(percutaneous coronary intervention,PCI)术后左室节段功能评价中的应用价值.方法:选择67例2011年1月～2012年6月于我院急诊行PCI治疗的急性前壁心肌梗死患者为研究对象,分别于PCI术前和术后72小时、1个月、三个月及六个月内行超声心动图检查,测量其常规超声心动指标E/A及LVEF,并用STI技术测定左室基底部及心尖段的旋转角度及解旋角度.结果:PCI术后患者基底部与心尖部心肌节段旋转及解旋角度均显著提高(P均＜0.05),但LVEF仅在术后六个月较术前提高(P＜0.05),其余时间的E/A及LVEF的变化无统计学意义(P＞0.05).结论:PCI术后患者左室功能改善,表现在心肌节段旋转解旋角度提高,二维STI技术可定量评价PCI患者左室心肌功能的变化.     

应用电子散斑干涉术对单端固定桥的受载分析

本文目的是对单端固定桥的运动及其受力状态进行试验性研究。采用电子散斑干涉术这一新的光学技术分别对下颌单端固定桥修复前后进行４种垂直加载测试,观察实时显示的散斑干涉条纹图,并测量相应牙槽骨处的离面位移。     

Protrusion and actin assembly are coupled to the organization of lamellar contractile structures

Directed cell migration requires continuous cycles of protrusion of the leading edge and contraction to pull up the cell rear. How these spatially distributed processes are coordinated to maintain a state of persistent protrusion remains unknown. During wound healing responses of epithelial sheets, cells along the wound edge display two distinct morphologies: ‘leader cells’ exhibit persistent edge protrusions, while the greater majority of ‘follower cells’ randomly cycle between protrusion and retraction. Here, we exploit the heterogeneity in cell morphodynamic behaviors to deduce the requirements in terms of cytoskeleton dynamics for persistent and sporadic protrusion events. We used quantitative Fluorescent Speckle Microscopy (qFSM) to compare rates of F-actin assembly and flow relative to the local protrusion and retraction dynamics of the leading edge. Persistently protruding cells are characterized by contractile actomyosin structures that align with the direction of migration, with converging F-actin flows interpenetrating over a wide band in the lamella. Conversely, non-persistent protruders have their actomyosin structures aligned perpendicular to the axis of migration, and are characterized by prominent F-actin retrograde flows that end into transverse arcs. Analysis of F-actin kinetics in the lamellipodia showed that leader cells have three-fold higher assembly rates when compared to followers. To further investigate a putative relationship between actomyosin contraction and F-actin assembly, myosin II was inhibited by blebbistatin. Treated cells at the wound edge adopted a homogeneously persistent protrusion behavior, with rates matching those of leader cells. Surprisingly, we found that disintegration of actomyosin structures led to a significant decrease in F-actin assembly. Our data suggests that persistent protrusion in these cells is achieved by a reduction in overall F-actin retrograde flow, with lower assembly rates now sufficient to propel forward the leading edge. Based on our data we propose that differences in the protrusion persistence of leaders and followers originate in the distinct actomyosin contraction modules that differentially regulate leading edge protrusion-promoting F-actin assembly, and retraction-promoting retrograde flow.     

Structure in the amphibian germinal vesicle

The germinal vesicle (GV) of Xenopus laevis is an enormous nucleus that contains 18 giant lampbrush chromosomes and thousands of inclusions. The inclusions are primarily of three types: approximately 1500 extrachromosomal nucleoli, 50-100 Cajal bodies, and several thousand B-snurposomes, which correspond to speckles or interchromatin granule clusters in other nuclei. The large size and abundance of the GV organelles, as well as the ease with which they can be studied both in vivo and in vitro, make the GV an ideal object for analysis of nuclear structure and function.     

Three-dimensional echocardiography for left ventricular quantification: fundamental validation and clinical applications

One of the earliest applications of clinical echocardiography is evaluation of left ventricular (LV) function and size. Accurate, reproducible and quantitative evaluation of LV function and size is vital for diagnosis, treatment and prediction of prognosis of heart disease. Early three-dimensional (3D) echocardiographic techniques showed better reproducibility than two-dimensional (2D) echocardiography and narrower limits of agreement for assessment of LV function and size in comparison to reference methods, mostly cardiac magnetic resonance (CMR) imaging, but acquisition methods were cumbersome and a lack of user-friendly analysis software initially precluded widespread use. Through the advent of matrix transducers enabling real-time three-dimensional echocardiography (3DE) and improvements in analysis software featuring semi-automated volumetric analysis, 3D echocardiography evolved into a simple and fast imaging modality for everyday clinical use. 3DE provides the possibility to evaluate the entire LV in three spatial dimensions during the complete cardiac cycle, offering a more accurate and complete quantitative evaluation the LV. Improved efficiency in acquisition and analysis may provide clinicians with important diagnostic information within minutes. The current article reviews the methodology and application of 3DE for quantitative evaluation of the LV, provides the scientific evidence for its current clinical use, and discusses its current limitations and potential future directions.