彩色流速成像法超声流量测定的离体实验研究

目的研究彩色流速流量定量（ＣＶＩＱ）流量测定准确性的影响因素。方法采用离体装置产生稳流，比较不同条件下ＣＶＩＱ测值差别，比较一定条件下不同流量ＣＶＩＱ测值与容器收集法结果。结果聚焦、彩标、彩色充盈度对测值影响较大；取样框大小稍有影响；彩标基线位置调节（以不产生混迭伪差为限）、取样框位置、Ｍ型取样线位置、血流方向校正线位置、壁滤波、余辉、彩色采样次数、平滑度等无明显影响。ＣＶＩＱ测值变异系数在７．３％以内。一定条件下，不同流量（８８～３００ｍｌ／ｍｉｎ）ＣＶＩＱ测值的相对误差为－０．１％～＋３．６％。结论ＣＶＩＱ流量测定重复性好；测值与仪器调节有关；合理调节仪器，能较准确测量流量。     

CDFI评价M-3动作对颈动脉血流影响的价值

目的：探讨飞行中实施Ｍ－３动作时颈总动脉（ＣＣＡ）血流动力学变化及意义。方法：应用彩色多普勒血流显像（ＣＤＦＩ）测量３２名战斗机飞行员在地面＋１Ｇｚ条件下实施Ｍ－３动作时ＣＣＡ收缩期峰１速度（Ｖｓ１）、收缩峰２速度（Ｖｓ２）、舒张峰速度（ＶＤ）、舒张末速度（Ｖｄ）、平均血流速度（Ｖｍ）、血流量（Ｖ）、心率（ＨＲ）、心水平收缩压（ＨＳＰ）、血管阻力指数（ＲＩ）、搏动指数（ＰＩ）等参数。结果：与动作前平静状态参数比较,Ｖｓ２、ＶＤ、Ｖｍ、Ｖ和ＨＳＰ分别提高４１％、３１％、２３％、２６％和５６％（Ｐ＜０．０１）,ＲＩ和ＰＩ分别降低７％和２６％（Ｐ＜０．０１）,Ｖｍ与Ｖ间呈正相关（ｒ＝０．６９,Ｐ＜０．０５）,Ｖｓ１、Ｖｄ和ＨＲ与平静时比较无显著性差异（Ｐ＞０．０５）。结论：Ｍ－３动作能增加静脉回心血量,提高大动脉血压,加快ＣＣＡ的Ｖｓ２、ＶＤ和Ｖｍ值,降低脑血管阻力,有利于维持脑部供血     

彩色多普勒检测颈内动脉狭窄的方法和准确性

目的探讨彩色多普勒诊断颈内动脉狭窄的方法及准确性。方法采用彩色多普勒检测８３例颈动脉硬化症患者,１２８侧颈内动脉起始处有不同程度狭窄。按狭窄程度分成三组,轻度（１～３９％）６９侧,中度（４０～６９％）４４侧,重度（７０～９９％）１５侧。测定颈内动脉收缩期峰值流速（ＩＣＡＳＰＶ）及颈内动脉与颈总动脉流速之比（ＶＩＣＡ／ＣＣＡ）。结果轻度狭窄时血流无明显改变,中度狭窄时,ＩＣＡＳＰＶ及ＶＩＣＡ／ＣＣＡ轻度增加;重度狭窄时,狭窄口呈现五彩色血流信号,ＩＣＡＳＰＶ及ＶＩＣＡ／ＣＣＡ均明显增加;尤以ＶＩＣＡ／ＣＣＡ敏感。部分超声检测结果与动脉造影及／或手术对照符合率为８９７１％。结论超声检查诊断颈内动脉起始处狭窄准确、无创,可作为临床首选方法;判断狭窄程度应以颈内与颈总动脉流速之比作为主要依据,结合峰值流速及二维切面图检测情况;中度狭窄,ＶＩＣＡ／ＣＣＡ＞１４,ＩＣＡＳＰＶ＞９５ｃｍ／ｓ;重度狭窄,ＶＩＣＡ／ＣＣＡ＞３０,ＩＣＡＳＰＶ＞２００ｃｍ／ｓ。     

小剂量多巴胺对肠系膜上动脉闭塞休克兔动脉血及门静脉血乳酸浓度影响的研究

目的：探讨肠系膜上动脉闭塞（ＳＭＡＯ）休克兔动脉血和门静脉血乳酸浓度的变化,以及小剂量多巴胺（５ μｇ·ｋｇ－ １·ｍ ｉｎ－ １）对其的影响。方法：２０只新西兰家兔随机分成２组,均制成ＳＭＡＯ 休克模型,２组均按３０ ｍ ｌ·ｋｇ－ １·ｈ－ １输入０．９％ ＮａＣｌ;Ａ组另给予多巴胺５ μｇ·ｋｇ－ １ ·ｍ ｉｎ－ １,Ｂ组作为对照组。分别观察血流动力学、动脉血和门静脉血乳酸浓度（ＡＬＴ、ＰＬＴ）,以及腹腔组织氧供（ＳＤＯ２）、氧耗（ＳＶＯ２）和氧摄取率（ＳＯ２ＥＲ）的变化。结果：Ａ组门静脉血流量指数（ＱｐｖⅠ）在休克模型复制后６０、９０ 和１２０ 分钟时明显高于Ｂ组（Ｐ＜ ０．０５或Ｐ＜ ０．０１）;２ 组ＡＬＴ、ＰＬＴ均明显升高,以休克后０ 时为最高〔Ａ 组分别为（６．５±１．１）ｍ ｍ ｏｌ／Ｌ和（６．９±１．４）ｍ ｍ ｏｌ／Ｌ;Ｂ组分别为（６．４±０．８）ｍ ｍ ｏｌ／Ｌ和（６．８±１．２）ｍ ｍ ｏｌ／Ｌ〕,但Ａ 组在此后呈逐渐下降趋势,在１２０分钟时最低〔分别为（３．２±０．３）ｍ ｍ ｏｌ／Ｌ和（３．５±０．３）ｍ ｍ ｏｌ／Ｌ〕,而Ｂ组则呈持续高水平〔分别为（５．５±０．５）ｍ ｍ ｏｌ／Ｌ和（５．７±０．９）ｍ ｍ     

特普他林对油酸性肺损伤鼠肺泡液体清除功能的影响

目的：观察特普他林对油酸致伤大鼠肺损伤后肺泡上皮液体清除能力的影响。方法：采用大鼠油酸型肺损伤模型。大鼠伤后２４小时经气管滴注特普他林（１×１０－ ４ ｍ ｏｌ／Ｌ）溶液５ ｍ ｌ／ｋｇ;１ 小时后检测肺泡内液体清除率（ＡＬＣ）、总肺水量（ＴＬＷ）、肺血管外肺水量（ＥＶＬＷ）和动脉血气参数。结果：大鼠伤后２４ 小时ＡＬＣ降低４９．２％ ,ＴＬＷ 和ＥＶＬＷ 明显增加〔分别由（３．１４±０．１４）ｍ ｌ／ｇ 和（２．２５±０．１１）ｍ ｌ／ｇ 增至（４．０４±０．１３）ｍ ｌ／ｇ和（４．３２±０．１１）ｍ ｌ／ｇ〕,严重的低氧血症〔ＰａＯ２ 为（６．５５±０．２３）ｋＰａ（１ ｋＰａ＝ ７．５ ｍ ｍ Ｈｇ）〕。特普他林组ＡＬＣ较油酸致伤组增高６３．７％ ,ＴＬＷ 和ＥＶＬＷ 显著减少〔分别为（３．３９±０．１６）ｍ ｌ／ｇ 和（２．９４±０．１２）ｍ ｌ／ｇ〕。钠转运特异性抑制剂 阿咪洛利或哇巴因能部分抑制特普他林刺激肺泡内液体清除的作用。结论：特普他林通过上调钠主动转运机能,促进肺水肿液的吸收,从而改善换气功能,对急性肺损伤后肺水肿有一定的治疗作用     

酶循环法测定血清总胆汁酸

采用氧化型β－硫烟酰胺腺苷二核苷酸（Ｔｈｉｏ－ＮＡＤ）底物酶循环法测定血清总胆汁酸（ＴＢＡ）,对其方法学进行初步研究。该法灵敏度：试剂空白△Ａ４０５ｎｍ（１ｃｍ）０．００４／ｍｉｎ;５０μｍｏｌ／Ｌ△Ａ４０５ｎｍ（１ｃｍ）０．０５０／ｍｉｎ;平均回收率９９．２％;线性０￣１５０μｍｏｌ／Ｌ;精密度：批内ＣＶ〈１．０％;批间ＣＶ〈４．５％;该法（Ｙ）和偶联黄递酶比色法（Ｘ）比较：Ｙ＝０．８８Ｘ－１．     

经股静-动脉心肺转流对犬心脏停搏后脑氧供需关系的影响

目的：观察犬电击致心室颤动－心脏停搏（ＶＦ－ＣＡ）８分钟后经开多心肺复苏（ＣＰＲ）和（或）经股静－动脉心肺转流９ＣＰＢ）心肺复苏对脑氧供需关系的影响。方法：采用犬经胸壁电击ＶＦ－ＣＡ ８分钟,经ＣＰＲ恢复自主循环（ＲＳＣ）后观察４小时内脑氧利用率（Ｏ２ＵＣ）和脑静脉血氧分压（ＰｓｓＯ２）的变化。９只犬分为２组,Ⅰ组（５只）采用开胸心脏按压等方法复苏,Ⅱ组（４只）于开胸心脏按压同时经一侧股静,动脉心     

彩色多普勒能量图在烟雾病诊断中的价值

目的　探讨彩色多普勒能量图（ＣＤＥ） 对烟雾病的诊断价值。方法　对１７例经ＤＳＡ确诊的烟雾病患者及２５例健康对照者大脑前、中、后动脉（ＡＣＡ、ＭＣＡ、ＰＣＡ）、颈总、颈内、颈外动脉（ＣＣＡ、ＩＣＡ、ＥＣＡ）以及颞浅动脉（ＴＳＡ）的阻力指数（ＲＩ）、搏动指数（ＰＩ）及平均血流速度（Ｖｍ ）进行检测分析。结果　①ＣＤＥ对颅内血管狭窄及闭塞的正确诊断率为８７．２５％ ; ②烟雾病患者颅外血管ＣＣＡ、ＩＣＡ表现为流速下降, 阻力升高, 而ＴＳＡ恰恰相反; ③ＣＤＥ显示１０例患者颅底异常血管网, 即对５８．８２％ 的患者做出烟雾病诊断。结论　ＣＤＥ可将烟雾血管显示为星星点点的血流信号, 在烟雾病的诊断中具有较高的临床应用价值。     

HCV感染基因型病毒复制程度与肝病关系的研究

采用限制性内切酶Ｓａｕ３Ａｌ和ＨａｅⅢ对５４例ＲＴ－ＰＣＲ法ＨＣＶＲＮＡ阳性的５＇ＮＣ区扩增产物进行酶切分型；ＰＣＲ滴定法半定量分析ＨＣＶＲＮＡ含量。结果显示４种酶切类型：ＨＣＶⅠ型感染３．７％（２／５４），ＨＣＶⅡ型感染７７．８％（４２／５４），ＨＣＶⅢ、Ⅳ型感染１１．１％（６／５４），ＨＣＶⅠ、Ⅱ／Ⅲ、Ⅳ型混合感染７．４％（４／５４），ＨＣＶⅡ型感染阳性率在ＡＨ、ＣＡＨ、ＬＣ三组间无显著差异（     

高渗氯化钠和维生素C治疗模拟高原失血性休克山羊血浆溶酶体酶活性的观察

将模拟在４０００ｍ高原停留２４小时的山羊２６只随机分为生理盐水对照组（ＮＳ）、高渗盐水治疗组（ＨＳ）和维生素Ｃ治疗组（ＶＣ）。在模拟高原环境下经股动脉放血至血压为５．３３±０．６７ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ），并维持６０分钟。分别经静脉注入０．９％ＮａＣｌ、７．５％ＮａＣｌ和维生素Ｃ，３０分钟后，回输血液行容量复苏。结果：①ＨＳ组和ＶＣ组动物再灌注后的存活时间显著延长，１２小时存活率显著提高。②ＮＳ组失血后出现明显酸中毒并逐渐加重，由代偿转为失代偿，ＨＳ组和ＶＣ组再灌注后２小时酸中毒得到改善，ｐＨ恢复至平原正常范围。③ＮＳ组在休克期及再灌注后血浆溶酶体酸性磷酸酶（ＡＰ）、β葡萄糖醛酸苷酶（βＧ）活性显著升高，并随时间呈上升趋势，而ＨＳ组和ＶＣ组再灌注后２小时血浆ＡＰ和βＧ活性趋于稳定，且ＨＳ组ＡＰ、βＧ活性及其增量ΔＡＰ、ΔβＧ和ＶＣ组ＡＰ、ΔＡＰ和ΔβＧ均显著低于ＮＳ组。相关分析显示，ＡＰ与βＧ活性及ΔＡＰ与ΔβＧ均呈显著正相关。实验结果提示：溶酶体膜稳定性增强、水解酶释放减少是７．５％ＮａＣｌ、大剂量维生素Ｃ治疗高原失血性休克的细胞学基础。推测可能与改善酸中毒和维生素Ｃ的抗氧化作用有关     

颈动脉血流量测定：彩色速度显像定量超声的临床应用

目的：应用彩色速度显像定量超声（ＣＶＩ－Ｑ）测量颈动脉血流量。方法：应用ＣＶＩ－Ｑ对２３例正常人、１５例甲亢患者、１４例桥本病患者颈动脉血流量进行了测定。结果：①正常人单侧颈动脉血流量为２９２．３４±８７．７３ｍｌ／ｍｉｎ;②甲亢、桥本病患者颈动脉血流量较正常人增高（Ｐ＜０．０１）;③甲亢、桥本病患者颈动脉血流量间无显著差异。结论：ＣＶＩ－Ｑ是一种可靠的测量颈动脉血流量的方法、具有潜在的临床应用价值。     

Measurement of volume flow with time domain and M-mode imaging: in vitro and in vivo validation studies.

Color velocity imaging quantification is a commercially available technique that estimates volume flow within vessels by combining velocity data, acquired by time domain correlation, with vessel diameter measurements obtained by M-mode imaging. By integrating the velocity profile over time, quantitative volume flow calculations may be made. To investigate the accuracy of this system, we used two flow phantoms over a range of steady and pulsatile flows for in vitro evaluation, and the common carotid artery of 10 women on five consecutive occasions was insonated for in vivo assessment. In flow phantom studies, accuracy was within 8% for flows above 200 ml/min, but decreased at lower flows depending on the depth, beam-vessel angle used, and steering of the beam. At angles greater than 70 degrees, velocity errors made quantitative measurement of flow unreliable, whereas at angles less than 30 degrees, the increased error in calculating vessel diameter led to large errors of area estimation, and hence made flow measurements unreliable. For the in vivo studies on the carotid artery the intraoperator repeatability values for the three operators were 9.92% (A), 13.74% (B), and 13.24% (C). The interoperator repeatability for the group was 15.30%. This study suggests that the color velocity imaging quantification technique is an accurate and reproducible method of assessing volume flow in vessels. However, in our experience, obtaining volume flow data is more time consuming and operator dependent than traditional Doppler techniques. The color velocity imaging quantification system may be of use in monitoring conditions in which changes in volume flow in a vessel or to an organ is an important part of the disease process.     

A new angle-independent Doppler ultrasonic device for assessment of blood flow volume in the extracranial internal carotid artery.

OBJECTIVE: To evaluate a new angle-independent ultrasonic device for assessment of blood flow volume in the internal carotid artery. METHODS: In vitro, a pulsatile pump was set to provide an outflow of physiological fluid at 500 mL/min through an 8-mm-diameter tube. Flow volume rates were measured 10 times by 10 different operators and compared with time-collected flow volume rates. In vivo, internal and common carotid artery blood flow volumes were measured in 28 volunteers by 2 operators using a FlowGuard device (Biosonix Ltd). Internal and common carotid artery diameters and blood flow volumes were also assessed by Duplex sonography and compared with FlowGuard measurements. In 10 volunteers, internal carotid artery blood flow volume changes in response to monitored breath manipulations were recorded. RESULTS: In vitro, intraoperator variability was 4.04% (range, 2%-5.7%). The mean error rate +/- SD was 3.54% +/- 0.8% (range, 2.7%-5.2%). In vivo, the mean common carotid artery blood flow volume was 456 +/- 39 mL/min (range, 417-583 mL/min) with a mean diameter of 6.7 +/- 0.7 mm (range, 5.8-8.7 mm). The mean internal carotid artery blood flow volume was 277 +/- 25 mL/min (range, 239-338 mL/min) with a mean diameter of 5 +/- 0.5 mm (range, 4.1-6.1 mm). No significant difference was found between operators. Internal carotid artery diameter and blood flow volume measured by the FlowGuard were closely correlated with the results of Duplex sonography. Repeated shifts of end-tidal CO2 induced reproducible changes in internal carotid artery flow volume: 187.5 +/- 18.1 mL/min at 26.8 +/- 1.9 mm Hg and 382.1 +/- 18.2 mL/min at 47 +/- 2.2 mm Hg. CONCLUSIONS: The FlowGuard showed that volume flow studies in the internal carotid artery could be easily performed, with results compatible with those of previous clinical reports. Duplex comparative results and breath-induced changes in internal carotid artery flow volume justify further evaluation of the system.     

Measurement of coronary flow using high-frequency intravascular ultrasound imaging and pulsed Doppler velocimetry: in vitro feasibility studies.

The recent development of intravascular ultrasound imaging offers the potential to measure blood flow as the product of vessel cross-sectional area and mean velocity derived from pulsed Doppler velocimetry. To determine the feasibility of this approach for measuring coronary artery flow, we constructed a flow model of the coronary circulation that allowed flow to be varied by adjusting downstream resistance and aortic driving pressure. Assessment of intracoronary flow velocity was accomplished using a commercially available end-mounted pulsed Doppler catheter. Cross-sectional area of the coronary artery was measured using a 20 MHz mechanical imaging transducer mounted on a 4.8 F catheter. The product of mean velocity and cross-sectional area was compared with coronary flow measured by timed collection in a graduated cylinder by linear regression analysis. Excellent correlations were obtained between coronary flow calculated by the ultrasound method and measured coronary flow at both ostial (r = 0.99, standard error of the estimate [SEE] = 13.9 ml/min) and distal (r = 0.98, SEE = 23.0 ml/min) vessel locations under steady flow conditions. During pulsatile flow, calculated and measured coronary flow also correlated well for ostial (r = 0.98, SEE = 12.7 ml/min) and downstream (r = 0.99, SEE = 9.3 ml/min) locations. That the SEE was lower for pulsatile as compared with steady flow may be explained by the blunting of the flow profile across the vessel lumen by the acceleration phase of pulsatile flow. These data establish the feasibility of measuring coronary artery blood flow using intravascular ultrasound imaging and pulsed Doppler techniques.     

Verifying complete obliteration of carotid artery-cavernous sinus fistula: role of color Doppler ultrasonography.

The purpose of this study was to evaluate the role of color Doppler ultrasonography in verifying obliteration of carotid artery-cavernous sinus fistula before and after therapeutic embolization or gamma knife radiosurgery. Before treatment, carotid artery-cavernous sinus fistula showed the following data on color Doppler ultrasonography: (1) increased blood flow in the common carotid artery (220 to 1264 ml/min with mean+/-SD of 728+/-378 ml/min); internal carotid artery (435 to 1097 ml/min with mean+/-SD of 834+/-216 ml/min) in fistulas of the direct type; and external carotid artery (85 to 257 ml/min with mean+/-SD of 170+/-75 ml/min) in fistulas of the indirect type in comparison to the contralateral side; (2) reverse pulsatile flow or spiculated wave form with turbulent flow in the engorged superior ophthalmic vein on the lesion side in all patients. All of the above abnormal hemodynamic changes became normal in six patients immediately after first embolization, in two patients with balloon embolization combined with subsequent direct embolization by direct puncture through the superior orbital fissure or internal carotid artery embolization, and in five patients after gamma knife radiosurgery at 4, 4, 8, 9, and 9 months, respectively. Color Doppler ultrasonography might be a good modality in long-term follow-up of carotid artery-cavernous sinus fistula after gamma knife radiosurgery and embolization.     

Doppler ultrasound measurement of cerebral blood flow in healthy pregnant women

Purpose To compare global cerebral blood supply in healthy pregnant women and nonpregnant women. Materials and Methods Flow volumes in the common, internal, and external carotid, arteries and the vertebral arteries were determined using color Doppler ultrasonography in 17 nonpregnant women, 55 healthy pregnant women at 10 to 40 weeks gestation, and 24 puerperal women within 1 week after spontaneous delivery. Global cerebral blood flow was defined as the sum of flow volumes in the bilateral internal carotid and vertebral arteries. Results In the nonpregnant group, mean flow volumes of the common, internal, and external carotid arteries and the vertebral arteries, and mean global cerebral blood flow volume were (mean±SD) 863±108 ml/min, 554 ±94 ml/min, 386±65 ml/min, 115±24 ml/min, and 669±104 ml/min, respectively. During the second trimester, flow volumes of the common and external carotid arteries increased significantly in the healthy pregnant women, to about 130 percent and 140 percent of the nonpregnant level, respectively. Global cerebral blood flow volume remained unchanged during pregnancy. Conclusion During pregnancy, increase in flow volumes in the common carotid arteries were accompanied by elevated flow volumes of the external carotid arteries but not the internal carotid arteries. This distribution would tend to regulate the volume of global cerebral blood flow throughout the period of pregnancy.     

Binswanger病的颈动脉多普勒超声检查

目的：用彩色多普勒超声观察Binswanger病（BD）患者颈动脉形态及血流动力学的改变。方法：观察了48例BD患者和性别、年龄相匹配的48例健康对照组两侧颈总动脉内中膜厚度、斑块情况及收缩期峰速、舒张未流速。结果：BD组,颈动脉内径增宽、颈总动脉内中膜厚度较对照组明显增厚,发现斑块32例,占66．7％,而对照组8例,占16．7％。同时发现,BD组颈总动脉收缩期峰速和舒张未流速均明显低于对照组。结论：BD病同颈部动脉硬化有关,其发生和脑部的低灌注有密切关系。     

Volumetric measurements of the brachial and carotid arteries in dialysis grafts: is there evidence of a subclavian-carotid artery steal syndrome?

Dialysis grafts may lead to major hyperperfusion in the graft arm and to hypertrophic, hypervolemic cardiomyopathy. No data have been published concerning the impact of dialysis grafts on the cerebral perfusion in relation to a potential carotid steal syndrome, possibly causing neurologic or neuropsychologic symptoms. In 30 patients (32 to 74 years old) with dialysis grafts we studied the following hemodynamic parameters in the brachial and common carotid arteries bilaterally: Flow velocities (spectral Doppler sonography), diameter (B-mode) and volume flow (color M-mode) with a color duplex system (Philips P700). Volume flow in the brachial arteries of the graft arm averaged 1032 ml/min (range, 158 to 2854 ml/min) as compared to 42 ml/min (range, 15 to 108 ml/min) in the nongraft arm. Almost identical volume flow data could be seen in both common carotid arteries (418 versus 421 ml/min) with no evidence of reduced flow in the carotid arteries in patients with high flow in the graft arm. A tendency toward higher volume flow in both carotid arteries in patients with high volume flow in the graft arm was noted. We found no evidence of shunt-induced cerebral hypoperfusion. Cerebral autoregulation appears to be patent even with high brachial artery shunt volume.     

Assessment of coronary blood flow in humans using phase difference MR imaging

Coronary blood flow quantification provides essential information on the hemodynamic significance of coronary artery stenoses. Recently, magnetic resonance (MR) flow mapping has emerged as a new promising method to noninvasively determine flow velocity and flow volume within the coronary arteries. The aim of this study was to compare phase difference (PD) MR flow quantification with intracoronary Doppler flow measurements in 15 patients with suspected or known coronary artery disease. Flow quantification was attempted before and after systemic application of 5mg Isosorbiddinitrate (ISDN) in order to determine possible alterations in coronary flow volume. PD MR flow mapping was performed successfully in 13 of the 15 patients. For flow velocities and flow volume values, a close correlation between PD MR and Doppler flow measurements was found (r = 0.79 and r = 0.90, respectively). However, average flow measured by PD MR was significantly lower than the invasively obtained values (9.0 ± 4.4 cm/sec vs. 11.7 ± 4.9 cm/sec; p<0.001 and 46.3 ± 28.7 ml/min vs. 53.4 ± 32.8 ml/min; p<0.05). Although the mean flow volume remained constant in the entire patient group after ISDN application, individual changes (increase in 6, decrease in 4 cases) could be documented with PD MR imaging and showed a good correlation to the Doppler method (r = 0.82). In conclusion, PD MR flow mapping is a promising method for the noninvasive quantification of coronary blood flow and therefore offers the potential of assessing coronary artery stenoses. However, technical improvements are mandatory in order to increase accuracy of the method.     

超声造影评价正常成人脑血流循环时间

目的 应用超声造影检测正常人的脑循环时间(cerebral circulation time,CCT).方法 选择47例无心脑血管病史的志愿者,应用高频超声检测颈内动脉及椎动脉的血流量,选取同时显示颈内动脉及颈内静脉的切面,由肘正中静脉团注超声造影剂SonoVue后存储图像,应用分析软件根据时间峰值曲线准确测量CCT并进行分析.根据剂量不同将受检者分为三组.当血流信号恢复到基线信号强度后,在对侧重复测定一次.根据CCT计算脑血容量,并进行统计分析.结果 47例受检者中颈部血管图像均可清晰获得,计算脑血流量为603～990 ml/min,平均(778±171)ml/min;双侧CCT均可成功检测,CCT为4.1～10.2 s,平均(6.22±1.47)s.左右两侧CCT差异无统计学意义(P＞0.05).不同注射剂量组CCT差异无统计学意义(P＞0.05).根据脑血流量及CCT计算脑血容量为54～96 ml,平均(76±27)ml.结论 结合颈部血管超声,超声造影检测CCT可以准确、便捷地估测脑血容量.