Relationship between portal blood flow measured by image-directed doppler ultrasonography and hepatic blood flow measured by indocyanine green constant infusion in patients with cirrhosis

The validity of portal blood flow measurement in image-directed Doppler ultrasound (PBF-IDU) is still under debate. In this study PBF-IDU has been compared with hepatic blood flow measured by the indocyanine green constant infusion technique (HBF-ICG), which is the reference invasive method with which to measure total hepatic blood flow in man (ie, the sum of hepatic artery and portal vein blood flow). In 27 cirrhotic patients with hepatopetal portal blood flow, PBF-IDU was measured by multiplying the portal vein cross-sectional area by the averaged mean velocity of blood in the vessel. About 1 hour later HBF-ICG was measured during hepatic vein catheterization performed to evaluate portal hypertension. In 19 of 27 patients, intra-hepatic arterial resistance indices were also measured. PBF-IDU and HBF-ICG were 1.010 ± 0.555 L/min (M ± SD) and 1.496 ± 0.731 L/min, respectively. Blood flow measured by the two methods showed a close correlation (r = 0.80, p < 0.001). The regression line showed that HBF-ICG was systematically higher than PBF-IDU (mean difference + 29 ± 30%). The hepatic artery component of HBF-ICG probably accounted for the difference. An inverse correlation was found between the differences between the two procedures and intrahepatic arterial resistance indices (r = ?0.52, p = 0.04), which may be considered indirect parameters of arterial supply. It can be concluded that image-directed Doppler ultrasound is a sufficiently accurate method to measure portal blood flow in cirrhotics. © 1995 John Wiley & Sons, Inc.     

Effect of epidural anaesthesia on dorsal pedis arterial diameter and blood flow

Summary. In nine subjects the influence of low (LE: blockade at or below the umbilicus; Th. 10) and high epidural anaesthesia (HE: block above the umbilicus) on vascular tone was evaluated by high frequency ultrasound (20 mHz) determined luminal diameter and a Doppler (8 mHz) assessment of mean blood flow velocity (V_mean) in the dorsalis pedis artery. The LE was induced by 0–5% bupivacain through a catheter at L₃-L₄, and HE was established by further infusion. Resting blood pressure and heart rate were not affected by LE or HE. One subject developed selective thoracic anaesthesia, and another was blocked on the contralateral side only. In the seven adequately blocked subjects, the luminal diameter of the dorsalis pedis artery increased from 1.70 (1.25–1.93) to 1.90 (1.75–2.23) mm during LE (+12%) and further to 2.08 (1.83–2.96) mm during HE (22%; P<0.05). The V_mean was similar during control (7 [4–26] cm s^-1) and LE (12 [4–55] cm s^-1), but increased during HE to 35 (12–78) cm s^-1 (+500%; P<0.05). Thus, arterial blood flow was higher during LE (21 [7–98] ml min^-1; +263%) and HE (94 [21–177] ml min^-1; +1175%) than at rest (8 [7–36] ml min^-1; P<0.05). This study quantified the importance of sympathetic nerve activity for vascular tone and in turn blood flow in an artery of a resting human limb, as the diameter and V_mean increased with progressive epidural anaesthesia.     

妊高征患者子宫动脉血流动力学的超声研究

目的：探讨妊娠高血压综合征（妊高征）患者子宫动脉血流动力学变化规律及临床意义。方法：应用彩色多普勒超声对47例中晚期妊娠妇女的子宫动脉进行前瞻性研究。根据临床最后诊断将受检查者分为妊高征组（41例）和正常妊娠组（106例）,对比分析两组受检查子宫动脉血流动力学变化及超声图表现,结果：（1）在妊娠21周以前,两组受检者子宫动脉血流参数相差不显著（P＞0．05）。（2）妊娠21周以后,妊高征组子宫动脉收缩期峰血流速度（Vp)较正常妊娠组快,舒张期最小血流速度（Vmin)和平均血流速度（Vmin)减慢（P＞0．01）,妊高征组子宫动脉阻力指数（RI）和搏动指数（PI）比正常妊娠组高（P＜0．01）,收缩期加速度（ACC）增快（P＜0．01）,妊高征组子宫动脉阻力指数（RI）和搏动指数（PI）比正常妊娠组高（P＜0．01）,收缩期加速度（ACC）增快（P＜0．01）,加速时间（AT）和射血时间（ET）缩短（P＜0．05）,妊高征组子宫动脉多普勒频谱表现典型者出现舒张早期“V”切迹,结论：妊高征患者子宫动脉血流动力学和多普勒频谱形态与正常妊娠妇女有明显的不同,常规定期监测中晚期妊娠妇女子宫动脉血流动力学变化及多普勒频谱形态,对早期发现和治疗妊高征,保障母婴健康具有极其重要的意义。     

Role of retrograde flow in the shear stimulus associated with exercise blood flow

To test the hypothesis that retrograde flow influences the shear stimulus of exercise blood flow, eight healthy men [25.6+/-3.1 years (SD)] performed 20 min of single-leg knee-extension exercise at two contraction velocities: fast (FR, 1.5 m s(-1)) and slow (SR, 0.4 m s(-1)). Contraction frequency (30 cpm) and workload (5 kg) were kept constant resulting in a work rate of 15.25 W for both contraction velocities. Common femoral artery diameter and blood velocity were measured at rest and during exercise using ultrasound Doppler. Mean blood flow was not different between contraction velocities while antegrade (2012.4+/-379.9 versus 1745.6+/-601.5 ml min(-1); P=0.05) and retrograde (121.7+/-43.0 versus 11.2+/-6.6 ml min(-1); P<0.001) flows were higher during FR than SR contractions, respectively. Despite the similar mean blood flow response, vascular resistance was lower during FR than SR contractions (0.06+/-0.01 versus 0.08+/-0.03 units; P=0.03) and was closely related to shear rate (pooled data: r=-0.77, P<0.01). Retrograde flow was associated with a lower vascular resistance during exercise (pooled data: r=-0.48, P相似文献   

经阴道彩超检测正常和病理早期妊娠黄体血流状况的探讨

目的观察比较正常和病理早期妊娠中的黄体血流状况,分析其意义。方法采用经阴道彩超声检查215例早期妊娠的孕妇,检出妊娠黄体205例,其中正常早期妊娠组148例、先兆流产组25例、宫外孕组22例,观察卵巢内黄体血流分布特点,检测收缩期峰值流速Vmax)、阻力指数RI及搏动指数PI。结果(()()1经阴道彩超对早期妊娠黄体总检出率95.3%,其中正常组检出率99.38/150);先兆流产组96.1%/26);宫外孕组75.8%(((22/29)。2三组妊娠黄体血流分布特点无差异,均呈连续环状分布。3先兆流产组黄体血流的PVS、PI、RI与正常早期妊娠组比较无差异(P>0.05),宫外孕组病人的黄体血流PVS比正常妊娠组的PVS低(P<0.05),PI、RI与正常组比较无差异(P>0.05)。结论经阴道彩色多普勒超声可以准确地识别妊娠黄体,血流指标中收缩期峰值流速在鉴别正常早孕与宫外孕可能有一定帮助。     

Color Doppler evaluation of changes in uterine perfusion induced by the use of an absorbable cervical tourniquet during open myomectomy

PURPOSE: To evaluate the hemodynamic changes in uterine perfusion following the vascular occlusion of the uterine arteries with an absorbable cervical tourniquet applied during open myomectomy. METHODS: Twenty-eight patients with symptomatic fibroids and a clinical uterine size equivalent to 14 or more weeks' gestation underwent open myomectomy. Patients were randomized to either the tourniquet or the control group. In the tourniquet group, a number 1 polyglactin suture was tied around the cervix to occlude the uterine arteries and left in situ. Doppler flow measurements were obtained at 5 days, 6 weeks, 3 months, and 6 months postoperatively and compared with preoperative values. RESULTS: Fourteen women were randomized to each group. Data were obtained from 12 patients in the tourniquet group and 11 in the control group. There were no statistically significant differences between the two groups for uterine artery at 5 days, 6 weeks, 3 months, or 6 months postoperatively. However, the peak systolic velocity was significantly reduced in the tourniquet group compared with the control group at 5 days (p < 0.05); thereafter, there were no significant differences between the two groups. CONCLUSIONS: A polyglactin cervical tourniquet causes only a temporary effect on uterine perfusion, which is consistent with its absorption profile.     

Preoperative ultrasonographic evaluation of testicular volume and blood flow in patients with inguinal hernias.

OBJECTIVE: The purpose of this study was to investigate whether an inguinal hernia would have an impact on the testicular volume and blood flow by scrotal ultrasonography. METHODS: Twenty-six male patients with unilateral inguinal hernias with a mean age of 48.1 years were included in the study. Testicular volumes were calculated, and spectral parameters such as the pulsatility index and resistive index of the testicular artery at supratesticular, subcapsular, and intratesticular levels on both the side with the inguinal hernia and the contralateral side were measured by a preoperative ultrasonographic examination. Comparisons between the dependent groups were performed by a Wilcoxon or paired samples t test where appropriate. RESULTS: The mean +/- SD testicular volume on the side with the inguinal hernia was significantly higher than that on the contralateral testis (15.46+/-4.49 versus 14.54+/-3.65 mL, respectively; P<.05, Student t test). In addition, the mean resistive index of the intratesticular arteries was significantly higher on the side with the hernia compared with the contralateral side (0.66+/-0.06 versus 0.63+/-0.05; P<.05, Student t test). CONCLUSIONS: These data indicate that an inguinal hernia may impair testicular blood flow, which may be attributable to an intermittent mechanical compression effect on the funiculus spermaticus in the inguinal canal.     

经阴道三维超声在子宫肌壁间妊娠诊断中的价值

目的 总结子宫肌壁间妊娠的超声声像图特征,探讨阴道三维超声对子宫肌壁间妊娠的诊断价值。 方法 结合手术及病理结果,综合国内外有关文献,回顾4 例子宫肌壁间妊娠患者经阴道三维超声检查结果,总结其声像图特点,分析误诊原因。 结果 4例患者中3例经阴道三维超声诊断正确,1例经阴道二维超声误诊为宫角妊娠,该例经阴道三维超声复查后提示子宫肌壁间妊娠。结论 阴道三维超声对子宫肌壁间妊娠的诊断有重要价值。     

The relationship between blood flow and pulsatility index in the superior mesenteric artery at rest and during constrictor stimuli in normal subjects

The relationships between superior mesenteric artery blood flow (SMABF) and pulsatility index (PI) measurement during rest (25 subjects) and stimuli constricting the SMA (16 subjects) have been studied in normal subjects. At rest and during constrictor stimuli, SMABF and PI were highly reproducible (r = 0.89, p < 0.01 for SMABF, and r = 0.97, p < 0.001 for PI) between two observers. There was significant correlation between changes in SMABF, PI, and SMA vascular resistance during the constrictor stimuli, except during head-up tilt when PI was unchanged. Both PI and SMABF measurements are reproducible and can be used to monitor physiological changes in suitable (18 of 25) subjects. PI measurement, although semiquantitative, by itself can also be used to monitor these changes. This may be also of importance in pathological situations such as intestinal ischemia, where measurement of volume blood flow may be less accurate due to irregularities of the vessel wall. PI measurement, however, ideally should not be used in studies involving postural change. © 1994 John Wiley & Sons, Inc.     

数字减影血管造影对双侧大脑中动脉峰值流速的影响

目的 通过对数字减影血管造影(DSA)患者造影前后双侧大脑中动脉峰值流速改变的观察,探讨DSA对其的影响.方法 应用经颅多普勒超声(TCD)扫描仪动态监测DSA患者在各个时间点的双侧大脑中动脉峰值流速的改变.结果 注药侧、非注药侧两组之间的大脑中动脉峰值流速差异无统计学意义(P＞0.05);双侧大脑中动脉各个时点峰值流速存在波动,差异有统计学意义(P＜0.01),注药侧大脑中动脉峰值流速在注完药后迅速下降,从穿刺前30 s的(98.1±32.4) cm/s到(90.5±32.2) cm/s,随之上升,达到最高值(112.2±37.8) cm/s,随之逐渐下降,于拔鞘后恢复到注药前水平;非注药侧大脑中动脉峰值流速在注药前各时点无明显变化,但在注完药后峰值流速明显上升(110.9±42.0)cm/s,趋于平稳后开始下降,于拔鞘后恢复注药前水平;组间和不同时点的交互作用差异有统计学意义(P＜0.01),两者的变化趋势明显不同.结论 虽然DSA可能影响大脑中动脉峰值流速的变化,但其仍有较高的安全性.     

经阴道彩色多普勒能量超声对早期诊断输卵管异位妊娠的临床研究

目的探讨经阴道彩色多普勒能量超声(TV-CDE)在早期诊断输卵管异位妊娠的检测价值。方法应用TV-CDE技术对98例临床疑诊异位妊娠患者的附件区包块行阴道二维超声图像、血流显像及频谱特征进行对照分析,对Vs、Vd、RI、PI值进行测量,分析了TV-CDE对异位妊娠定性的可行性。结果①异位妊娠包块血流信号丰富,血管连续性好,能较完整显示血管床、血管网及范围广的低流速血流信号;②脉冲多普勒取样为滋养层周围性血流频谱,其特征为频谱增宽、单相或双相持续存在、阻力降低(RI＝0.44±0.04)、舒张期血流丰富的动脉频谱;③具有鲜明丰富的滋养层周围性彩色血流频谱特征的“输卵管环”是早期输卵管妊娠的特征性表现,并提示是输卵管完整存在的标志。结论TV-CDE是目前诊断早期异位妊娠有价值的检测手段,其血流频谱特征和“输卵管环”具有特殊诊断及鉴别诊断意义,尤其是对异位妊娠早期诊断具有特异性。     

Impaired uterine arterial blood flow in pregnant women with recurrent pregnancy loss.

OBJECTIVE: This study was undertaken to evaluate uterine perfusion, which regulates uterine receptivity, in women with recurrent pregnancy loss. METHODS: We evaluated the blood flow resistance in the uterine arteries of 104 pregnant women at 4 to 5 weeks' gestation by transvaginal pulsed Doppler ultrasonography (control group, n = 52; and recurrent pregnancy loss group, n = 52). Blood tests for antinuclear and antiphospholipid antibodies were also performed. RESULTS: The uterine arterial pulsatility index in the recurrent pregnancy loss group was significantly higher than that in the control group. Women with antinuclear or antiphospholipid antibodies had an elevated pulsatility index in the uterine artery, which is prominent in women with recurrent pregnancy loss. Coagulopathy and vascular dysfunction caused by autoantibodies may impair uterine perfusion. However, the uterine arterial pulsatility index in the recurrent pregnancy loss group was significantly higher than that in the control group even among women without antinuclear antibodies or among women without antiphospholipid antibodies. This observation strongly suggests that the uterine artery pulsatility index may be an independent index for recurrent pregnancy loss. CONCLUSIONS: The introduction of pulsed Doppler ultrasonography has provided the means for noninvasive evaluation of uterine impedance and may identify patients with recurrent pregnancy loss associated with impaired uterine perfusion.     

多普勒超声信号分析定量评价自体静脉移植血管的管壁弹性和血流动力学变化

本研究以狗股静脉移植于股动脉为实验模型，采用Ｈｐ—１０００型彩色多普勒诊断仪（探头频率７．５ＭＨｚ），连续观察术后１２周内移植血管管壁弹性和流经移植血管段血流动力学变化。通过多普勒超声信号分析，定量评价了自体静脉移植血管的顺应性特点并计算了血流搏动指数。结果显示，移植血管的顺应性低于宿主动脉的顺应性，但术后１２周内无明显变化；血流搏动指数作为反映流经移植血管段的血流动力学的一项指标，术后１２周内无明显变化，且与术前无明显变化。