射流速度和射流量对射流大小影响的实验研究

本研究采用激光荧光红染料方法观察了射流速度、射流口径及射流量对射流大小的影响。射流量相同而射流口径及射流速度不同时，射流大小存在显著差异（Ｐ＜０．００１～０．０００１）。虽然射流量与射流大小显著相关（ｒ＝０．８７，Ｐ＜０．００１），但射流速度与射流大小的相关性比前者更显著（ｒ＝０．９２，Ｐ＜０．０００１）。研究提示临床放射及超声在半定量诊断瓣膜返流时除了考虑返流量对返流大小的影响外，在返流速度不一的情况下还需考虑返流速度对返流大小有较大影响。以免造成对关闭不全程度的高估或低估     

彩色多普勒血流会聚与众射流参数在二尖瓣返流定量中的价值

用血流会聚新方法及射流参数对二尖瓣返流定量的价值进行了研究。结果表明血流会聚法计算返流量与二尖瓣返流容积及返流分数相关性最佳。彩色多普勒射流参数与二尖瓣返流容积和二尖瓣返流分数的相关性不一，其中返流起始宽度与两者相关性分别为ｒ＝０．８７－０．９３，Ｐ＜０．０００１）．彩色多普勒射流参数与二尖瓣返流容积和二尖瓣返流分数的相关性不一，其中返流起始宽度与两者相关性分别为ｒ＝０．８８和０．８１（Ｐ＜０．０     

彩色多普勒过返流口宽度与射流参数评估二尖瓣返流的对照研究

目的：研究彩色多普勒过返流口宽度评估二尖瓣返流的价值。材料与方法：测量３１例二尖瓣关闭不全患者彩色多普勒过返流口宽度、返流长度、返流面积、瞬间返流容积及返流量和返流分数。结果：彩色多普勒过返流口宽度、返流长度、返流面积及瞬间返流容积与返流量的相关性分别为ｒ＝０．８７、０．４８、０．６５和０．６４；上述彩色多普勒参数与返流分数的相关性分别为ｒ＝０．８９、０．６１、０．７１和０．６４。彩色多普勒过返流口宽度预报重度二尖瓣返流的准确度（９３．５％～９６．８％）显著高于返流长度、返流面积及瞬间返流容积预报重度二尖瓣返流的准确度（７１．０％～７４．２％），Ｐ＜０．０５～０．０１。结论：彩色多普勒过返流口宽度是一种比返流束更好的评估二尖瓣返流的指标。     

彩色多普勒过返流口宽度估价二尖瓣关闭不全程度

本文比较了彩色多普勒过返流口宽度与返流长度、面积及瞬间返流容积在二尖瓣关闭不全程度评价中的作用。二尖瓣关闭不全程度用频谱多普勒测定的有效返流口面积确定。３０例二尖瓣关闭不全患者彩色多普勒过返流口宽度为：轻度关闭不全２．５７±０．４０ｍｍ，中度关闭不全３．２３±０．３６ｍｍ，重度关闭不全５．５２±１．１０ｍｍ。组间差异显著（Ｐ＜０．０１～０．００１）。彩色多普勒过返流口宽度、返流长度、返流面积及瞬间返流容积与有效返流口面积的相关系数分别为０．８５（Ｐ＜０．００１），０．４８（Ｐ＜０．０１），０．６９（Ｐ＜０．００１），０．６９（Ｐ＜０．００１）。彩色多普勒过返流口宽度受血流动力学影响小，能够更准确地判断二尖瓣关闭不全程度     

不同形状界面对界面射流的影响──彩色多普勒与激光荧光染料方法的研究

本文通过应用彩色多普勒及激光荧光染料显示射流方法研究了不同形状界面对射流的影响。结果表明对照组及平坦界面射流时，彩色多普勒与激光荧光染料两种方法无显著差异；在弯曲界面条件下，彩色多普勒射流小于激光荧光染料射流（Ｐ＜０．０１～０．０００１）。彩色多普勒研究表明不同形状界面射流大小分别与每搏容量相关好（ｒ＝０．８３～０．９９），但射流大小明显不同。凹形界面射流面积最小，平坦及凸形界面射流面积也小于对照组。研究提示不同形状界面可以导致界面射流不同程度地减小，并且彩色多普勒也不易对弯曲界面的射流完全成像。在临床上应用彩色多普勒对返流定量时，需考虑上述影响。     

测量有效返流口面积在二尖瓣关闭不全定量诊断中的价值

用彩色多普勒血流会聚方法测量了二尖瓣有效返流口面积，并探讨了该指标在二尖瓣关闭不全定量诊断中的价值。结果表明，这一指标与二尖瓣返流容积、返流分数，彩色多普勒返流起始宽度、返流面积具有良好的相关性（分别为ｒ＝０．８９、０．８４、０．８２及０．６７，Ｐ＜０．００１～０．０００１）。有效返流口面积≥３０ｍｍ２区别轻、中度与重度返流的准确度为９５．７％。有效返流口面积是一种较好的反映二尖瓣关闭不全的指标。     

混叠速度对血流会聚定量的影响

本研究对７３例二尖瓣关闭不全、二尖瓣狭窄及室间隔缺损患者观察了彩色多普勒混叠速度对血流会聚定量的影响。结果显示：二尖瓣关闭不全返流量的血流会聚定量选用３７～５８ｃｍ／ｓ混叠速度为佳。二尖瓣狭窄瓣口面积的血流会聚定量选用２９～３７ｃｍ／ｓ混叠速度较佳。而室间隔缺损分流量的血流会聚定量以４６～７１ｃｍ／ｓ混叠速度较好。混叠速度过低，血流会聚定量显著高于对照值（Ｐ＜０．０５～０．０１）。混叠速度过高，血流会聚定量显著低于对照值（Ｐ＜０．０１～０．００１）。二尖瓣关闭不全、二尖瓣狭窄及室间隔缺损组所选用的混叠速度均与血流会聚值呈显著负相关（ｒ＝－０．９５１～－０．９９７，Ｐ＜０．０５～０．００１）。因此，血流会聚定量应该注意选用合适的混叠速度。     

彩色多普勒血流会聚法对室间隔缺损分流程度的评估研究

本文应用彩色多普勒血流会聚法对２３例单纯室间隔缺损患者的分流程度进行评估，结果表明血流会聚法所测分而率Ｆ与频谱多普勒法所测的每搏分流量Ｑｐ－Ｑｓ及肺体循环血流量之比Ｑｐ／Ｑｓ之间均有极好的相关性（ｒ分别为０．９９和０．８７，Ｐ＜０．００１）。血流会聚区的简化指标ＮＬ×Ｒ及ＮＬ×Ｓ与Ｑｐ－Ｑｓ（ｒ＝０，９０～０．７３，Ｐ＜０．００１）及Ｑｐ／Ｑｓ（ｒ＝０．９３～０．８８，Ｐ＜０．００１）之间的相关性均很好。彩色多普勒血流会聚法能够快速、准确、无创地评估室间隔缺损的分流程度，其简化指标可以简便地对室间隔缺损的分流程度进行评估。     

血流动力学对能量多普勒显像的影响：血流速度的影响

目的：在实验模型中观察血流速度对能量多普勒显像（ＰＤＩ）的影响。方法：在３ｍｍ内径硅胶管中模拟不同血流速度（２．０～３３．２ｃｍ／ｓｅｃ）的血流。记录ＰＤＩ血流图，用计算机分析血流的彩色像素面积（ＣＰＡ）和彩色亮度（ＣＶ）。结果：血流速度与ＰＤＩ血流的ＣＰＡ和ＣＶ呈正相关，其中ＣＰＡ：ｒ＝０．８３４，Ｐ＜０．０１；ＣＶ：ｒ＝０．８４８，Ｐ＜０．０１，尤其在血流速度为８．３ｃｍ／ｓｅｃ以下时变化最明显。结论：血流速度对ＰＤＩ血流的血流面积和亮度均有影响。     

彩色多普勒血流会聚定量诊断室间隔缺损分流

本文应用彩色多普勒血流会聚法对２０例室间隔缺损患者的分流进行了定量研究，并观察了不同混叠极限对其定量的影响。结果显示：混叠极限为７１、５８、４６、３７和２９ｃｍ／ｓ时血流会聚分流量与频谱多普勒法所计分流量相关性好（ｒ＝０．９０－０．９４，Ｐ＜０．０００５），与肺／体循环量也呈显著相关（ｒ＝０．５９－０．６５，Ｐ＜０．０１）。其中以混叠极为５８ｃｍ／ｓ所求血流会聚分流量与频谱多普勒分流最最接近，分别     

Value and limitations of proximal jet dimensions for the quantitation of valvular regurgitation: an in vitro study using Doppler flow imaging

To evaluate usefulness and limitations of proximal jet dimensions for the quantitation of valvular regurgitation, fluid jets were created in a pulsatile flow model, and proximal jet width and cross-sectional area were measured by means of color Doppler flow imaging. When circular orifices with diameters from 1 to 6 mm were studied, jet width and cross-sectional jet area measured as close as possible to the orifice were directly related to the orifice diameter (r = 0.97; standard error of the estimate, 0.4 mm; y = 0.5 + 0.97x) and the orifice area (r = 0.97; standard error of the estimate, 5.7 mm2; y = 0.22 + 2.47x), respectively. No significant dependence on flow rate or pressure gradient was found for these measurements. Jet width was measured with color M-mode Doppler by use of the smallest sample volume size (1 mm) and was slightly greater than the orifice diameter (4.2 +/- 1.7 mm versus 3.8 +/- 1.7 mm). However, cross-sectional areas were approximately fourfold the orifice areas, on average (52.5 +/- 24.6 mm2 versus 12.3 +/- 9.7 mm2), with a range of twelvefold (smallest orifice) to threefold (largest orifice). When the sample volume size was reduced from 2.4 to 1.0 mm, color areas decreased by 25.6 +/- 6.0%. Slit-shaped orifices were studied with two different orientations of the slit-parallel and perpendicular to the ultrasound beam: Color M-mode measurements were again slightly greater than length and width of the slit, but cross-sectional areas were substantially larger than the orifice areas and increased between 44% and 115% when changing the orientation of the slit from perpendicular to parallel. This, again, reflected problems with lateral resolution. When cross-sectional areas were measured at increasing distances from the orifice, the cross-sectional jet area increased significantly within a few millimeters. This increase was greater with higher gradients and smaller orifice sizes. In case of a small orifice (2 mm) and a high gradient (130 to 160 mm Hg), increase in area was as great as 122% within a distance of only 5 mm. Thus, proximal jet width and cross-sectional area were directly related to the orifice size, which could be a valuable parameter for the evaluation of valvular regurgitation. Measurements of jet width by color M-mode seemed to be most accurate but are limited by the fact that in vivo valvular defects may be irregular rather than of circular shape.(ABSTRACT TRUNCATED AT 400 WORDS)     

实时三维彩色血流成像技术定量评价室间隔缺损分流量的初步探讨

目的探讨实时三维彩色血流成像技术(RT-3DCDFI)评价室间隔缺损分流量的价值。方法应用RT-3DCDFI成像技术采集46例单纯性室间隔缺损(VSD)患者的三维彩色分流信号数据,导入TomTec三维图像工作站,于收缩期采用八平面法勾画并计算分流束的彩色血流信号容积(SJV),并与二维频谱多普勒法QP-QS所测得分流量结果行相关性分析。结果①缺损直径小于或等于主动脉根部直径2/3的小、中VSD的SJV值与QP-QS值相关良好(r=0.87;r=0.79),且两者的均值无显著性差异(P>0.05);②缺损径线大于主动脉根部直径2/3的大VSD,RT-3DCDFI所测SJV值明显低估分流量(r=0.55)。结论RT-3DCDFI技术可从三维空间对VSD分流进行评估,为临床定量评估中小型VSD的分流提供了一种新方法。     

多普勒超声对原发性肝癌肝动脉化疗栓塞的疗效评价

目的:探讨多普勒超声评价经肝动脉化疗栓塞术(TACE)治疗原发性肝癌(HCC)疗效的价值。方法:对51例原发性肝癌TACE术前、术后行多普勒超声检查，用二维超声观察肿瘤大小及内部回声改变。彩色多普勒超声(CDFI)观察肿瘤血供情况及脉冲多普勒(PW)记录肝动脉、门静脉血流动力学改变。结果:TACE术后大多数肿瘤均有不同程度缩小,肿瘤血供明显减少(P<0.001),其血供减少程度与肿瘤缩小程度呈正相关(r=0.757,P<0.001)。肝动脉峰值流速明显下降，门静脉血流速度增快(P<0.001)。结论:多普勒超声能客观判断肿瘤大小及血流灌注状态，是目前检验肝癌TACE术后效果较理想的影像学检查方法之一。     

Doppler color flow in echocardiography: analytical and in-vitro investigations of the quantitative relationship between orifice flow and color jet dimensions

The goal of this investigation was to explore the relationship between orifice flow rate and the dimensions of the resulting color jet. Equations were derived which describe flow rate as a function of the color jet dimensions, instrument characteristics, and a coefficient which represents the unknown velocity profile across the jet. Experiments in which fluid was injected at a variety of flow rates via an assortment of orifice sizes into a compliant, axisymmetric chamber were performed for comparison with the analytical results. During each injection, orifice flow rate and color jet dimensions were recorded. The experimental results were closely predicted (r = 0.97) by an equation which expresses flow rate as a function of the ratio of the color jet area and color jet length, and with a coefficient which approximates that of a parabolic velocity profile.     

A new Doppler-echo method to quantify regurgitant volume.

An in vitro technique using color flow imaging and continuous wave Doppler was developed to measure the initial regurgitant flow jet diameter and velocity integral to yield the parameters for a volume calculation. Jets were produced by volume-controlled injection through tubes of various diameters (1.3, 1.9, 2.8, and 3.5 mm) to deliver volumes from 1 to 7 ml over 100 to 300 msec at pressures from 40 to 200 mm Hg. One hundred forty-five samples were obtained. Flow jet diameter consistently overestimated tube diameter by 2 mm when injected volume was 1.5 to 7 ml and by 1.5 mm when injected volume was less than 1.5 ml. This offset was stable with various transducers (2.5, 3.5, 5.0 MHz) at normal gain setting (just under noise). Therefore, corrected flow jet diameter (FJD) = FJD - 2 mm, and Doppler volume = corrected flow jet area x velocity integral. A range of injectates from 1.1 to 7 ml generated Doppler volume of 1.0 to 8.2 ml. The relation between Doppler volume (DV) and injected volume (IV) was DV = 1.079 IV - 0.22, r2 = 0.945, p less than 0.01. This relation was not altered by tube diameter. Thus a method combining color flow imaging and continuous wave Doppler provides a reliable and accurate measure of in vitro flow volume.     

Quantitative assessment of in vitro jets based on three-dimensional color Doppler reconstruction

Three-dimensional (3-D) color Doppler imaging of flow jets was performed to investigate the effects of flow rate and orifice size on jet volumes. Flow jets were generated using a flow model to simulate mitral regurgitation. This flow model consisted of a ventricular chamber, a valvular plate and an atrial chamber. Steady flow was driven through circular orifices having diameters of 2.5, 3.5, 4.5, and 6 mm, respectively, with flow rates of 5, 10, 15, 20, and 25 mL/s to form free jets in the atrial chamber. An ATL Ultramark 9 HDI system was used to perform 3-D color Doppler imaging of the flow jets. A transesophageal probe was rotated by a stepper motor to create 3-D color Doppler images of the jets. The color jet volumes for different hemodynamic conditions were measured and then compared with the theoretical predictions. Results showed that the jet volume estimated from the 3-D color Doppler was directly proportional to the flow rate and inversely proportional to the orifice size. The estimated jet volumes correlated well (r > 0.95) with theoretical predictions. This study supports the use of color jet volume as a parameter to quantify mitral regurgitation.     

左室流出道血流对室间隔缺损左室面血流会聚区影响的研究

本文对２３例单纯膜部室间隔缺损患者，通过校正左室流出道血流对会聚区的影响，计算出校正后的分流率Ｆｃ，并根据Ｆｃ计算出校正后的缺损口面积Ａｃ。结果表明校正后所得分流率Ｆｃ与频谱Ｄｏｐｐｌｅｒ法所测Ｑｐ－ＱＳ及Ｑｐ／Ｑｓ具有极好的相关性（ｒ分别为０．９５和０．８１，Ｐ＜０．００１）。而且校正后的缺损口面积Ａｃ与二维切面上直接测得的缺损口直径Ｄｄ之间较由血流会聚法测得的未校正的分流率Ｆ计算出的缺损口面积Ａ与Ｄｄ之间具有更好的相关性（ｒ分别为０．９８和０．６９，Ｐ＜０．００１）。该研究表明通过校正左室流出道血流对会聚区的影响计算出的分流率能更准确地评估室间隔缺损的分流程度。     

彩色多普勒血流会聚法评估偏心性二尖瓣返流的临床价值

观察３０列显示血流会聚区的偏心性二尖瓣返流患者的返流束形态，发现均为附壁细长束。返流束面积、返流束面积／左房面积与频谱多普勒法及血流会聚法测定的参数比较左相关性均较差，相关系数分别为０．５９、０．５６及０．５５、０．５７，耐血流会聚法所测返流率与频谱多普勒法所测返流量则高度相关，相关系数为０．９６（Ｐ＜０．０１）。