灰阶超声和彩色多普勒超声诊断早期乳腺癌的价值

目的探讨超声声像图特征对早期乳腺癌诊断价值.方法84例女性患者(89个肿瘤)术前分别进行灰阶超声、彩色多普勒超声检查,观察肿块的形态、边缘、内部回声及钙化、肿块后回声以及肿块内血流信号情况.结果84例患者手术病理证实乳腺导管癌的7例,早期浸润癌的32例,良性肿瘤45例.灰阶超声、彩色超声多普勒对导管内癌及早期浸润性癌诊断的准确率分别为80.7%,79.3%和59.9%,65.9%.结论超声诊断早期乳腺癌目前主要依靠灰阶超声.     

彩色多普勒高频超声在女性乳腺增生症中的诊断价值

目的:探讨彩色多普勒高频超声对乳腺增生症的诊断价值,以提高超声对乳腺增生症的诊断价值。方法:观察59例经手术病理或病理活检证实为乳腺增生症患者的乳腺声像图及血流情况。结果:乳腺增生症的声像特点分为以下四种类型:(1)单纯性增生:共28例;(2)囊性增生:共6例;(3)腺瘤样增生:共6例:(4)混合型:以上三型同时存在,共19例。结论:彩色多普勒高频超声诊断女性乳腺增生症具有重要的临床诊断价值。     

乳腺癌彩色多普勒超声的诊断价值

目的:分析彩色多普勒超声诊断乳腺癌的价值.方法:选择2012年2月至2020年2月期间乳腺癌患者40例作为研究对象,采用随机数字表法将其均分为两组,各20例,分别为对照组和观察组.其中对照组采用常规乳腺癌检测方法,观察组则采用彩色多普勒超声检测方法.观察两组患者检测乳腺癌的准确率.结果:经过检测,观察组检测乳腺癌的准确...     

B2 彩色多普勒超声心动图诊断先天性心脏病的价值

彩色多普勒血流显像(CDFI)在二维超声显示心脏形态结构的基础上,同时实时显示心脏及大血管内血流的剖面图,进一步提高了超声诊断先心病的正确率。现将我院自1988年至1991年间经CDFI检查并有手术治疗的先天性心脏病611例总结分析于下。     

急性输尿管结石彩色多普勒超声诊断价值分析

目的:分析在对急性输尿管结石患者诊断中应用彩色多普勒超声的临床价值。方法:抽取院内自2017年4月起,到2019年1月止诊治的56例急性输尿管结石病人为回顾分析对象,患者术前均以彩色多普勒超声检查,并于手术病理结果对比,分析诊断价值。结果:本组56例患者经手术病理确诊均为急性输尿管结石,结石数量共计62个,包括上段和下段结石42个,中段结石20个。彩色多普勒超声诊断上段和下段结石40个,中段结石19个,诊断准确率为95.16%,与手术病理结果相比并无显著差异(P>0.05)。结论:彩色多普勒超声在急性输尿管结石患者中具有较高的诊断应用价值,可为患者的临床诊断提供参考。     

彩色多普勒超声对下肢血管狭窄性疾病的诊断研究

目的:探讨彩色多普勒超声对下肢血管狭窄性疾病的诊断研究。方法:选取59例患者作为本次研究对象,所有患者均采用多普勒超声技术检查、数字减影血管造影(DSA)技术检查,彩色多普勒超声检查结果与DSA检查结果进行比较,分析彩色多普勒超声检查的特异度和灵敏度。结果:患者下肢血管闭塞的节段数116节,重度狭窄22节,中度狭窄52节,轻度狭窄57节,彩超检查与DSA检查符合率分别为89.922%、68.750%、76.470%、89.815%。结论:下肢血管狭窄性疾病采用彩色多普勒超声检查有无创、简便、可重复、安全等多种优势,且准确率较高,值得临床推广。     

瞬时弹性成像联合彩色多普勒超声规范化半定量评分在早期肝炎肝硬化诊断中的应用价值研究

目的：观察早期肝炎肝硬化诊断中瞬时弹性成像与彩色多普勒超声规范化半定量评分联合应用价值。方法：于2021年1月至2022年1月纳入50例慢性乙肝患者作为观察对象,均进行肝脏活检、彩色多普勒超声以及瞬时弹性成像检查,采用ROC曲线分析单一彩色多普勒超声、单一瞬时弹性成像以及二者联合诊断早期肝炎肝硬化的相关性。结果：彩色多普勒超声规范化半定量评分的ROC曲线下面积0.717,95%CI可信区间0.515～0.919,特异性88.24%、敏感性50.00%、准确性76.00%;瞬时弹性成像的ROC曲线下面积0.899,95%CI可信区间0.779～1.02,特异性91.18%、敏感性68.75%、准确性84.00%;彩色多普勒超声规范化半定量评分与瞬时弹性成像联合检查的ROC曲线下面积0.936,95%CI可信区间0.846～1.01,特异性97.06%、敏感性93.75%、准确性96.00%。结论：早期肝炎肝硬化诊断过程中,彩色多普勒超声规范化半定量评分与瞬时弹性成像联合检查具有较高的准确度,有助于临床规范化抗病毒治疗,减缓肝硬化进展,值得现代临床广泛借鉴。     

彩色多普勒超声鉴别诊断乳腺良恶性肿瘤的效果

目的：研究乳腺良恶性肿瘤鉴别诊断中行彩色多普勒超声检查的效果。方法：数据取自本院2019年9月至2022年3月收治的80例乳腺肿瘤疾病患者,以病理检查结果为诊断“金标准”,再行彩色多普勒超声,分析诊断结果。结果：病理检查、超声检查比较良恶性肿瘤检出率无差异,P>0.05;与良性肿瘤比较,恶性肿瘤Ⅱ级、Ⅲ级占比更高,0级、Ⅰ级比例更低,P<0.05。结论：彩超可准确鉴别诊断乳腺良恶性肿瘤,尽早明确疾病、值得推崇。     

彩色多普勒超声对移植肾血管并发症的诊断价值

目的:彩色多普勒超声检查可较敏感地反映移植肾血流动力学的改变,随时观察移植肾的成活情况,评价彩色多普勒超声在移植肾血管并发症中的应用效果。方法:回顾性分析9例移植肾血管并发症患者的彩色多普勒超声结果,观察肾结构、肾内血流信号的分布、肾静脉主干回声和血流充盈情况,测量主肾动脉、段动脉、叶间动脉及弓形动脉流速及阻力指数、搏动指数。结果:对2007年9月-2012年9月10例移植肾血管并发症进行分析,5例肾动脉狭窄,1例肾动脉栓塞,1例肾静脉狭窄,2例肾静脉血栓及1例假性动脉瘤。结论:彩色多普勒超声具有简便、迅速、无创、可重复性等优点,已成为肾移植后临床观察治疗效果的首选监测手段。它能客观、动态显示移植肾形态结构及其内部的血流分布,血流频谱形态、流速、舒张期血流方向和血流指数变化,及时发现移植肾血管并发症,查找导致移植肾功能损害的部分原因,早期明确诊断并给予及时治疗,对提高肾移植成功率起重要作用。     

彩色多普勒超声在子宫肌瘤与子宫腺肌病鉴别诊断中的应用

目的：对比分析彩色多普勒超声在子宫肌瘤与子宫腺肌病鉴别诊断中的应用价值。方法：选择2020年1月至2021年1月在昭平县人民医院治疗的94例子宫肌瘤患者与90例子宫腺肌病患者临床资料进行回顾性分析,研究对象均实施彩色多普勒超声检查,术后病理诊断结果作为诊断金标准,比较两组患者的超声诊断准确率、超声血流参数情况与超声图像特征。结果：超声诊断准确率：以病理活检为金标准,彩色多普勒超声检查结果显示,94例子宫肌瘤中确诊91例,诊断准确率是96.81%,90例子宫腺肌病中确诊87例,诊断准确率是96.67%,两种疾病通过彩色多普勒超声检查的诊断准确率对比无统计学意义（P>0.05）;超声血流参数：彩色多普勒超声检查发现,子宫肌瘤患者的子宫动脉阻力、舒张期峰值速度、收缩期峰值速度、血流波动指数等数值均低于子宫腺肌病患者,比较具有统计学意义（P<0.05）;超声图像特征：子宫肌瘤患者边界清楚,肿块多呈球形或类球形,肿块内可见存在旋涡,并血管向外扩张。子宫腺肌症患者没有明显的圆球状病灶,但多普勒超声显示子宫内有明显的弥漫性扩大,有一小片筛孔样的暗影,并有较散在的血管。结论：彩色多普勒超声...     

关于前列腺经直肠实时灰阶超声谐波造影技术的现状及思考

1研究的重要性 前列腺癌在欧美国家是第二位高发病率的男性恶性实体肿瘤,死亡率仅次于肺癌.在国内随着前列腺特异性抗原检测的广泛应用,前列腺癌的患病率似乎愈来愈高,在我科几乎每周均遇到在超声引导下穿刺活检确诊的前列腺癌病例.     

CIELAB色空间内窥镜色彩还原能力对比分析

基于CIELAB色空间评价硬性内窥镜色彩还原能力,并进行4支硬性内窥镜色彩还原能力对比分析.通过与内窥镜连接的工业相机拍摄内窥镜观测到的色彩标靶图像,拍摄图像发送至计算机保存并处理.处理后得到图像中红绿蓝色块的RGB值,将RGB值转换至CIELAB色空间进而求得图像的L*、a*、b*值,最后利用已知标靶色块的L*、a*、b*值和求得的图像L*、a*、b*值计算CIELAB色差△Eab*,即色彩还原误差值.实验数据表明:4支内窥镜的色彩还原误差值都在47.9以上;4号腹腔镜对红、绿、蓝三色块的色彩还原误差值最小,色彩还原能力最好;2号宫腔检查镜对三色块色彩还原误差值比较大,色彩还原能力最差;1号鼻窦镜和3号关节镜的色彩还原能力处于中间水平.CIELAB色空间作为国际通用的测色标准,可以用于评价硬性内窥镜色彩还原能力.     

Optimizing the constant-channel chromaticity and color gamut of CRT color displays by control of brightness and contrast levels

Before a CRT color display is calibrated, the levels of the brightness and contrast controls should be considered. These levels have different effects on the relationship between the chromaticity coordinates of the red-green-blue (RGB) channels and the voltage applied to the gun as well as on the color gamut. Using three different CRT color displays, we measured both these relationships as well as the color gamut for different combinations of brightness and contrast levels. With respect to the luminance range of the white point provided by each display, the results show that the assumption of constant-channel chromaticity of the RGB channels is more valid at medium- to low-brightness levels in combination with high-contrast levels. In addition, this assumption holds at high contrast and medium- to low-brightness levels, the color gamut being optimized at these combinations of levels, with regard to the size of the triangle of primaries-the maximum luminance of the display white point.     

人上尿路病变腔内微探头导管超声与X线静脉尿路造影的比较研究

目的比较腔内微探头导管超声与X线静脉尿路造影对人上尿路病变的诊断价值.方法导管超声及X线静脉尿路造影(IVP)检查30例病人.所有病例均经手术证实或其他检查方法验证.结果导管超声对肾盂内肿瘤的显示率为92%(12例/13例),IVP的显示率为54%(7例/13例);大小<10mm的肾盂内肿瘤的显示率导管超声为100%(6例/6例),IVP只有17%(1例/6例);导管超声能够准确定位肾盂旁肿瘤,显示肾盂旁血管畸形,明确输尿管梗阻病因,而IVP诊断较困难.结论IVP可作为上尿路病变的筛选性检查手段,腔内导管超声可作为后续性精细检查方法以进一步明确病变的部位、层次及性质.     

Assessment of harmonic distortion level considering the interaction between distributed three-phase harmonic sources and power grid

An iterative frequency domain-based harmonic analysis method for harmonic distortion assessment for systems with distributed harmonic sources has been proposed. The proposed method, unlike the traditional method, is able to consider harmonic attenuation and diversity due to the interaction between the harmonic sources and power grid. Time domain simulation for systems with distributed adjustable speed drives is used to validate the proposed method. Case studies are conducted to show the merits of the proposed method especially with a large number of distributed harmonic sources     

Comparative study of time and frequency domain BEM approaches in frictional contact problem for antiplane crack under harmonic loading

Two different boundary element methods (BEM) for crack analysis in two dimensional (2-D) antiplane, homogeneous, isotropic and linear elastic solids by considering frictional contact of the crack edges are presented. Hypersingular boundary integral equations (BIE) in time-domain (TD) and frequency domain (FD), with corresponding elastodynamic fundamental solutions are applied for this purpose. For evaluation of the hypersingular integrals involved in BIEs a special regularization process that converts the hypersingular integrals to regular integrals is applied. Simple regular formulas for their calculation are presented. For the problems solution while considering frictional contact of the crack edges a special iterative algorithm of Udzava's type is elaborated and used. Numerical results for crack opening, frictional contact forces and dynamic stress intensity factors (SIFs) are presented and discussed for a finite III-mode crack in an infinite domain subjected to a harmonic crack-face loading and considering crack edges frictional contact interaction using the TD and FD approaches.     

Comparative study between the PNL method and a MN in modelling fatigue of composite materials

The aim of this study was to compare the results obtained using the piecewise nonlinear model with those of a modular network (MN) architecture in modelling fatigue behaviour. We used a database consisting of ten materials derived from the literature and represented by the following acronyms: C10, C12, DD16, HTA‐913, IM7–977, MAT(0)₂, T800–5245, T800H‐3631, QQ1 and QQ1T. The results obtained by MN were compared with those of the PNL. The results for both the PNL and MN model were satisfactory for the fatigue behaviour of glass fiber‐based composite materials, but for carbon fiber‐based composites only MN showed satisfactory results.     

经阴道超声在输卵管异位妊娠早期诊断中的应用价值

目的:探讨分析经阴道超声在输卵管异位妊娠早期诊断中的临床应用价值。方法:对我院自2013年01月至2015年03月来院的190例疑似输卵管异位妊娠患者,对其进行早期经阴道超声诊断,并将结果与最终临床诊断进行比较分析。结果:190例疑似输卵管异位妊娠患者,经手术后均得到确诊。术前经阴道超声诊断后确诊为187例,正确率为98.42%。其中,壶腹部妊娠168例(88.42%),峡部妊娠16例(8.42%),间质部妊娠3例(1.58%)。误诊2例(1.05%),漏诊1例(0.53%)。结论:经阴道超声对早期诊断输卵管异位妊娠准确率高,误诊及漏诊率低,为患者及时有效的治疗提供了临床依据,具有良好的临床应用价值。     

Low-order AR models for mean and maximum frequency estimation in the context of Doppler color flow mapping

Autoregressive (AR) techniques are investigated by developing mean and maximum frequency estimators suitable for use in Doppler color flow mapping systems, where they are most needed. The estimators are based on low-order (for computational efficiency) AR models applied to complex signals whose real and imaginary parts are the in-phase and quadrature components of the analytical Doppler signal, respectively. A large number of simulated data sequences generated by a sinusoidal computer model and having different number of samples, spectral shapes, bandwidths, and signal-to-noise ratios are used to examine the performance (bias and variance) of the estimators in a systematic manner. Comparisons are made with the established autocorrelation technique, whose output is shown to be identical to one of the AR mean frequency estimators described.     

On the performance of regression and step-initialized IIR clutterfilters for color Doppler systems in diagnostic medical ultrasound

One of the major issues in color Doppler ultrasound is the suppression of clutter that arises from stationary or slowly moving tissue. If not adequately suppressed, clutter can severely affect the ability of color Doppler systems to accurately estimate the Doppler mean frequency and power of blood, resulting in a potentially misleading depiction of flow. In this study, the performances of two classes of clutter suppression techniques-step-initialized infinite impulse response (IIR) and regression filters-were evaluated and compared by means of extensive simulations. The performance indicators used were the accuracy and precision of the mean frequency and the power estimates after clutter filtering. In summary, the ability of both filter classes to suppress clutter was found to vary considerably depending on factors such as the clutter-to-flow-signal ratio and the ensemble length. In particular, the performance of step-initialized IIR filters was shown to be noticeably inferior to that predicted by their steady-state response. Regression filters were found to offer significantly better performance than step-initialized IIR filters under heavy clutter conditions and, given their steeper roll-off, appear to be more effective clutter suppressors for power Doppler imaging. However, it should be noted that, as demonstrated by the simulations, the performance of IIR filters is severely degraded by their transient response which, in turn, is determined by the initialization scheme used. Therefore, more elaborate schemes-with superior transient characteristics than step-initialization-could significantly improve the effectiveness of IIR filtering under heavy clutter conditions