应用超声微泡对肝肾微循环血流速度及血流状态的研究

目的应用超声微泡实时直接测量正常肝肾微循环血流速度并研究血流状态。方法采用10只实验犬用"DFY型超声图像定量分析仪"观测肝、肾实质正常微循环的血流速度和血流状态。结果肝、肾微循环的血流速度分别为(0.82±0.17)mm/s和(1.19±0.38)mm/s。肾微循环的平均血流速度大于肝(P0.05)。结论本实验所用方法是一种无创、动态实时、直接测量深部脏器微循环血流速度的新技术方法。微循环变化是疾病的基础病变和先期病变,血液微循环障碍的最重要表现之一,就是血流速度的减慢和停滞,因而了解微循环状态对疾病的诊治和预后判断意义重大。目前,临床上尚无无创、动态实时、直接、准确测量深部脏器微循环血流速度并观察微循环状态的实用方法。     

应用超声微泡对正常和不同程度缺血心肌微循环血流速度及血流状态的研究

目的 通过单个超声微泡研究正常及不同缺血程度下的心肌微循环血流速度及血流状态.方法 采用15只实验犬用"DFY型超声图像定量分析仪"观测心肌正常微循环的血流速度.建立不同程度冠脉狭窄的心肌缺血模型,并观测缺血心肌的血流状态及速度.结果 正常心肌微循环的血流速度为(6.25±1.27)mm/s,心肌50%、90%和100%缺血时心肌微循环的血流速度分别为(2.3±0.57)mm/s、(0.1±0.04)mm/s和(0.05±0.01)mm/s.随冠脉狭窄程度加大血流速度明显减慢(P＜0.05).结论 本实验所用方法是一种无创、动态实时、直接测量心肌微循环血流速度的新技术.     

L-S靶向超声造影微泡淋巴结造影的实验研究

目的 探讨自制L-S (lymph-selectin)靶向微泡用于淋巴结造影的效果.方法 雌性兔5只外阴埋置VX2鳞癌组织块制作兔外阴鳞癌及腹股沟转移淋巴结动物模型.A组先经兔耳缘静脉注入L-S靶向微泡(0.3 ml/kg),1h后再注入普通脂质微泡(0.3ml/kg);B组相反.以低机械指数超声检测两组中L-S靶向微泡和普通脂质微泡对腹股沟转移淋巴结的造影效果并进行对比分析.结果 L-S靶向微泡淋巴结造影表现为淋巴结整体回声明显增强,其灰阶值在A、B两组分别为:(97.18±8.38) dB和(92.36±9.45) dB;普通脂质微泡淋巴造影主要表现为淋巴结边缘部位回声增强,其灰阶值在A、B两组分别为:(83.12±2.81) dB和(80.27±3.56) dB.两组中,L-S靶向微泡与普通脂质微泡淋巴结造影的灰阶值比较,差异具有显著性(P＜0.05).结论 L-S靶向微泡具有明显增强淋巴结显影的作用.     

超声造影检测正常人及正常移植肝肝门部胆管微循环的对比研究

目的 获取正常肝门部胆管微循环超声造影表现资料.方法 选择正常人9例、正常移植肝6例行肝门部胆管壁超声造影检查,记录胆管壁、肝动脉和肝实质开始增强时间、胆管壁与肝实质开始增强时间之差、胆管壁增强消退至与肝实质回声相等及低于肝实质时间;记录注射造影剂后动脉期、门脉期及延迟期胆管壁增强水平.结果 正常人和正常移植肝胆管壁增强时间及增强水平均无统计学差异(P＞0.05).所有胆管壁均早于肝实质增强.动脉期,正常人以高增强为主(8/9),正常移植肝全部为高增强(6/6).门脉期和延迟期,正常人多为等增强(8/9),正常移植肝以等或低增强为主(5/6).结论 正常人与正常移植肝肝门部胆管壁增强特点为增强时间早于肝实质;增强水平在动脉期以高增强为主,门脉期和延迟期以等或低增强为主,两组无统计学差异.     

超声造影在放射学中的应用

现状:不考虑组织特性及仪器分辨率的影响,就声学造影剂而言,其应用可为超声显像提供更多的信息。它除可提高正常组织与病变组织的对比度外,任何造影剂在已知其药物动力学的情况下,对造影剂的诸如灌注率、清除率及一定时间内其在组织内聚集情况等有意义的生理信启、有较好的了解,将有助于对组织特性的认识。虽然超声在定量回声强度上有一定局限性,但对血中造影剂浓度的定量分析却取得了很大的成功。本文综述了超声造影在放射学中的应用现状及发展前景。     

超声造影心肌灌注显像的研究热点

近年来超声造影心肌灌注显像的研究有了重大进展．为临床医生了解冠状动脉的血流分布心肌灌注情况提供了一种全新的方法。静脉注射超声造影剂和心肌灌注定量测定将使该技术更广泛地应用于临床。     

超声造影对兔股骨头坏死微循环灌注的定量研究

目的探讨超声造影(CEUS)在激素致兔股骨头坏死微循环灌注中的诊断价值。方法 12只新西兰兔随机分为空白组与模型组,造模3周后均行CEUS检查,并与病理相对照。结果 AS、DS、TTP、mTT两组间比较均有统计学意义(P<0.05),其中TTP、mTT意义更为显著(P<0.01)。病理学空骨陷窝率及微血管密度计数组间比较亦具有统计学意义。结论 CEUS可从微循环灌注的改变定量分析早期股骨头坏死,可为早期股骨头坏死的诊断提供有利的影像学依据。     

超声造影在肠系膜淋巴结结核诊断中的应用价值

目的：分析肠系膜淋巴结结核的超声造影（CEUS）增强模式,评价CEUS在肠系膜淋巴结结核诊断中的应用价值。方法回顾性分析经粗针穿刺或手术切除病理证实为肠系膜淋巴结结核的62例患者,共62个淋巴结的常规超声及CEUS资料,观察淋巴结位置,淋巴结大小、长径（L）/短径（S）值、内部回声及后方回声改变。根据淋巴结最大径分为≤20 mm组和>20 mm组,并分析其CEUS的增强模式。结果62个肠系膜淋巴结结核常规超声表现为淋巴结回声不均匀减低,其中19个（30.6%）可见点状或团状钙化。肠系膜淋巴结结核CEUS增强模式有3种：环形增强29个（46.8%）,不均匀增强21个（33.9%）,无增强12个（19.3%）。≤20 mm组以环形增强型为主,>20 mm组以不均匀增强为主,2组间增强模式差异有统计学意义（χ2=6.782,P=0.034）。结论肠系膜淋巴结结核CEUS表现以环形及不均匀增强为主,不同大小的肠系膜淋巴结结核CEUS表现模式不同,CEUS可为肠系膜淋巴结结核的诊断提供有价值的信息。     

首荟通便胶囊对小鼠肠系膜微循环的影响及作用机制

目的 首荟通便胶囊对小鼠肠系膜微循环的影响及作用机制.方法 72只昆明小鼠随机分为对照组、模型组、复方血栓组、首荟通便胶囊低剂量组、中剂量组和高剂量组,首荟通便胶囊低剂量组、中剂量组、高剂量组小鼠每日给予0.10g/kg、0.30g/kg和0.90g/kg的首荟通便胶囊灌胃,复方血栓组每日给予0.40g/kg的复方血栓...     

超声造影检测移植肝肝门部胆管微循环的可行性研究

目的 探讨超声造影检测肝门部胆管微循环的可行性及其方法.方法 16例疑为移植肝胆道并发症者行肝门部胆管壁超声造影检查,按SonoVue用量不同(1.5 ml/次及2.4 ml/次)分为两组.比较两组的造影图像质量,图象质量分为优、一般、差三级.其中2例行二次肝移植者,以病肝标本为对照,了解术前常规超声及超声造影对肝门部胆管壁的显示是否准确.结果 16例胆管壁超声造影图像质量优良者8例(50%),一般者6例(37.5%),差者2例(12.5%).1.5 ml/次与2.4 ml/次剂量组间图像质量差异无统计学意义(P=0.78),两组图像质量优良及一般者均为7例(87.5%).2例肝门部胆管常规超声、超声造影图像与病肝标本对比表明,常规超声能准确显示肝门部胆管壁,超声造影则能检测出胆管壁内造影剂灌注状况.结论 肝门部胆管壁超声造影图象质量可满足诊断要求,能反映胆管壁微循环灌注.造影时每次注入1.5 ml SonoVue即可达到与2.4 ml相当的造影效果.     

CEUS联合CDFI评估四肢血管损伤手术指征的临床价值

目的 探讨超声造影(contrast-enhanced ultrasound,CEUS)联合彩色多普勒血流显像(color Doppler flow imaging,CDFI)评估四肢血管损伤肢体血供情况和手术指征的临床价值.方法回顾性分析47例四肢血管损伤患者CEUS与CDFI检查资料,重点观察四肢血管管壁连续性、管腔通畅程度及肢体远端侧支循环形成;检查结果与数字减影血管造影(DSA)或手术探查结果对比,并与临床诊断及治疗措施作相关性研究.结果 47例患者中,超声诊断结果包括4例部分动脉胁迫,5例完全动脉胁迫,2例动脉部分断裂,17例动脉完全断裂,5例动脉完全断裂并血栓,6例动脉内膜挫伤并血栓形成,2例动静脉痰,6例假性动脉瘤,诊断准确率为93.6% (44/47).手术患者16例,包括1例完全动脉胁迫,1例动脉部分断裂,2例动脉完全断裂,2例动脉完全断裂并血栓,3例动脉内膜挫伤并血栓形成,1例动静脉痰,6例假性动脉瘤.结论 CEUS联合CDFI诊断四肢血管损伤具有很高的准确性,可全面评估肢体血供情况,为临床手术治疗提供重要参考指征.     

多普勒角度校正功能对血流速度测量的影响

目的：为了强调正确使用多普勒角度校正功能在外周血管血流速度测量的重要性，我们测量不同角度下正常人颈总动脉血流速度频谱，分析了不同角度对多普勒血流测量影响。资料与方法：仪器应用美国Ａｃｕｓｏｎ１２８ＸＰ１０型彩色电脑声像仪，检测正常人不同取样角度下颈总动脉最大血流速度、速度时间积分及计算每分血流量。结果：当改变角度校正线时，测量数据产生明显变化，角度在２０°以内，每变化１０°，最大血流速度变化平均１－２ｃｍ／ｓ，每分血流量变化平均１０～２２ｍｌ；同样１０°变化，角度从５０°～６０°，最大血流速度则由平均７９～１０２ｃｍ／ｓ，每分血流量平均７１６～９１２ｍｌ。结论：在外周血管血流检测中，要注意精确地将角度校正线调整到与血流方向平行的位置上，尽量减小声束与血流方向夹角，以便获得可信的血流动力学信息     

Quantification of Ultrasound Correlation‐Based Flow Velocity Mapping and Edge Velocity Gradient Measurement

This study investigated the use of ultrasound speckle decorrelation‐ and correlation‐based lateral speckle‐tracking methods for transverse and longitudinal blood velocity profile measurement, respectively. By studying the blood velocity gradient at the vessel wall, vascular wall shear stress, which is important in vascular physiology as well as the pathophysiologic mechanisms of vascular diseases, can be obtained. Decorrelation‐based blood velocity profile measurement transverse to the flow direction is a novel approach, which provides advantages for vascular wall shear stress measurement over longitudinal blood velocity measurement methods. Blood flow velocity profiles are obtained from measurements of frame‐to‐frame decorrelation. In this research, both decorrelation and lateral speckle‐tracking flow estimation methods were compared with Poiseuille theory over physiologic flows ranging from 50 to 1000 mm/s. The decorrelation flow velocity measurement method demonstrated more accurate prediction of the flow velocity gradient at the wall edge than the correlation‐based lateral speckle‐tracking method. The novelty of this study is that speckle decorrelation‐based flow velocity measurements determine the blood velocity across a vessel. In addition, speckle decor‐relation‐based flow velocity measurements have higher axial spatial resolution than Doppler ultrasound measurements to enable more accurate measurement of blood velocity near a vessel wall and determine the physiologically important wall shear.     

Prenatal Diagnosis of Abnormal Invasive Placenta by Ultrasound: Measurement of Highest Peak Systolic Velocity of Subplacental Blood Flow

The aim of the study described here was to identify an efficient criterion for the prenatal diagnosis of abnormal invasive placenta. We evaluated 129 women with anterior placenta previa who underwent trans-abdominal ultrasound evaluation in the third trimester. Spectral Doppler ultrasonography was performed to assess the subplacental blood flow of the anterior lower uterine segment by measuring the highest peak systolic velocity and resistive index. These patients were prospectively followed until delivery and evaluated for abnormal placental invasion. The peak systolic velocity and resistive index of patients with and without abnormal placental invasion were then compared. Postpartum examination revealed that 55 of the patients had an abnormal invasive placenta, whereas the remaining 74 did not. Patients with abnormal placental invasion had a higher peak systolic velocity of the subplacental blood flow in the lower segment of the anterior aspect of the uterus (area under receiver operating characteristic curve: 0.91; 95% confidence interval: 0.87–0.96) than did those without abnormal placental invasion. Our preliminary investigations suggest that a peak systolic velocity of 41?cm/s can be considered a cutoff point to diagnose abnormal invasive placenta, with both good sensitivity (87%) and good specificity (78%), and the higher the peak systolic velocity, the greater is the chance of abnormal placental invasion. Resistive index had no statistical significance (area under receiver operating characteristic curve, 0.56; 95% confidence interval: 0.46–0.66) in the diagnosis of abnormal invasive placenta. In conclusion, measurement of the highest peak systolic velocity of subplacental blood flow in the anterior lower uterine segment can serve as an additional marker of anterior abnormal invasive placenta.     

血管内超声多普勒技术对Budd-Chiari综合征介入治疗前后 压力与血流速度变化的关系研究

目的　研究Budd Chiari综合征 (BCS)患者介入治疗 (PTA)前后的压力与平均峰值速度 (APV )的变化关系。方法　使用血管内多普勒导丝测定 2 7例BCS患者PTA前后的下腔静脉和 /或肝静脉 (IVC/HV )的血流速度 ,同时测定压力。结果　PTA前 ,在狭窄和闭塞病变 ,压力和APV呈负相关 (狭窄 :IVC :r =-0 .82 ,P <0 .0 0 1;HV :r =-0 .83 ,P <0 .0 0 1。闭塞 :IVC :r =-0 .45 ,P <0 .0 5 ;HV :r =-0 .44 ,P <0 .0 5 )。PTA后 ,无这种相关关系。结论　PTA前 ,在狭窄和闭塞血管 ,其狭窄远心端的压力与血流速度呈不同程度的负相关关系 ;而PTA后 ,这种相关关系消失。故简单的压力测量并不能完全替代血流速度的测量     

彩色多普勒对184例老年人眼底动脉硬化的血流检测

为了了解眼底动脉硬化时眼动脉和视网膜中央动脉的血流动力学变化，为诊断眼血管性疾病以及脑血管性疾病提供有价值的数据。我们采用Acuson-128型电脑声像仪，5MHz钱阵探头，对老年人眼底动脉进行了检测。结果发现老年人眼底动脉硬化与眼底正常者相比，收缩期流速峰值升高（P＜0．01），舒张末期流速下降（P＜0．01），阻力指数和搏动指数增加（P＜0．01）。老年人眼底动脉硬化者眼动脉和视网膜中央动脉的血流动力学发生了明显的变化，对诊断眼动脉硬化有重要的临床意义。     

运用彩色多普勒流速剖面图测定血流量的实验研究

运用实验血流模型，检测新近开发的彩色多普勒血流速度部面图（velocityprofile，VP）对血流量测定的准确性，并与脉冲型多普勒（PulsedwaveDoppler，PWD）测定法比较。结果显示在不同流速下两种方法的流量测值与实际流量间均有高度相关性，相关系数r分别为0．999（P＜0．001）和0．988（P<0．02）。但测得流量与实际流量之间的误差程度，VP法为-7.64～2．79％，PWD法为17.82～27.97％。表明VP法较PWD法更接近实际情况。     

Brain Blood Flow and Velocity

Objective. Because transcranial Doppler sonography (TCD) is unable to measure arterial diameter, it remains unproven whether the changes in cerebral blood velocity it measures are representative of changes in cerebral blood flow (CBF). Our study was designed to compare velocity changes with flow changes measured by two magnetic resonance imaging (MRI) techniques, perfusion MRI and arterial spin labeling (ASL), using flavanol‐rich cocoa to induce CBF changes in healthy volunteers. Methods. We enrolled 20 healthy volunteers aged 62 to 80 years (mean, 73 years). Each was studied at baseline and after drinking standardized servings of cocoa for 7 to 14 days. Results. Changes in middle cerebral artery (MCA) flow by TCD were significantly correlated with changes in perfusion assessed by gadolinium‐enhanced MRI (r = 0.63; P < .03). Measurements with ASL showed a stronger correlation with borderline significance. Conclusions. Changes in flow velocity in the MCA associated with drinking cocoa were highly correlated with changes in CBF measured by the two MRI techniques using the tracer gadolinium and ASL. These results validate Doppler measurements of CBF velocity as representative assessments of CBF.