Relationship between ultrasound parameters of the umbilical and middle cerebral arteries and intrauterine fetal distress

BACKGROUND By comprehensively analyzing the blood flow parameters of the umbilical and middle cerebral arteries,doctors can more accurately identify fetal intrauterine distress,as well as assess its severity,so that timely interventions can be implemented to safeguard the health and safety of the fetus.AIM To identify the relationship between ultrasound parameters of the umbilical and middle cerebral arteries and intrauterine distress.METHODS Clinical data of pregnant women admitted between January 2021 and January 2023 were collected and divided into the observation and control groups(n=50 each),according to the presence or absence of intrauterine distress.The ultrasound hemodynamic parameters of the uterine artery(UtA),fetal middle cerebral artery(MCA),and umbilical artery(UmA)were compared with neonatal outcomes and occurrence of intrauterine distress in the two groups.RESULTS Comparison of ultrasonic hemodynamic parameters,resistance index(RI),pulsatility index(PI),and systolic maximal blood flow velocity of UmA compared to diastolic blood flow velocity(S/D),revealed higher values of fetal MCA,PI,and S/D of UmA in pregnant women with UtA compared to controls(P<0.05),while there was no difference between the two groups in terms of RI(P<0.05)The incidence of a neonatal Apgar score of 8-10 points was lower in the observation group(66.7%)than in the control group(90.0%),and neonatal weight(2675.5±27.6 g)was lower than in the control group(3117.5±31.2 g).Further,cesarean section rate was higher in the observation group(70.0%)than in the control group(11.7%),and preterm labor rate was higher in the observation group(40.0%)than in the control group(10.0%).The incidence of fetal distress,neonatal growth restriction and neonatal asphyxia were also higher in the observation group(all P<0.05).CONCLUSION Fetal MCA,UmA,and maternal UtA hemodynamic abnormalities all develop in pregnant women with intrauterine distress during late pregnancy,which suggests that clinical attention should be paid to them,and monitoring should be strengthened to provide guidance for clinical intervention.

Transit time ultrasound perivascular flow probe technology is superior to MR imaging on hepatic blood flow measurement in a porcine model

Background: The hepatic hemodynamics is an essential parameter in surgical planning as well as in various disease processes. The transit time ultrasound(TTUS) perivascular flow probe technology is widely used in clinical practice to evaluate the hepatic inflow, yet invasive. The phase-contrast-MRI(PC-MRI) is not invasive and potentially applicable in assessing the hepatic blood flow. In the present study, we compared the hepatic inflow rates using the PC-MRI and the TTUS probe, and evaluated their predictive value of post-hepatectomy adverse events. Methods: Eighteen large white pigs were anaesthetized for PC-MRI and approximately 75% hepatic resection was performed under a unified protocol. The blood flow was measured in the hepatic artery(Qha), the portal vein(Qpv), and the aorta above the celiac trunk(Qca) using PC-MRI, and was compared to the TTUS probe. The Bland-Altman method was conducted and a partial least squares regression(PLS) model was implemented. Results: The mean Qpv measured in PC-MRI was 0.55 ± 0.12 L/min, and in the TTUS probe was 0.74 ± 0.17 L/min. Qca was 1.40 ± 0.47 L/min in the PC-MRI and 2.00 ± 0.60 L/min in the TTUS probe. Qha was 0.17 ± 0.10 L/min in the PC-MRI, and 0.13 ± 0.06 L/min in the TTUS probe. The Bland-Altman method revealed that the estimated bias of Qca in the PC-MRI was 32%(95% CI:-49% to 15%); Qha 17%(95% CI:-15% to 51%); and Qpv 40%(95% CI:-62% to 18%). The TTUS probe had a higher weight in predicting adverse outcomes after 75% resection compared to the PC-MRI( β= 0.35 and 0.43 vs β = 0.22 and 0.07, for tissue changes and premature death, respectively). Conclusions: There is a tendency of the PC-MRI to underestimate the flow measured by the TTUS probes. The TTUS probe measures are more predictive of relevant post-hepatectomy outcomes.

Assessment of Uterine Receptivity by Endometrial and Subendometrial Blood Flows Measured by Vaginal Color Doppler Ultrasound in Women Undergoing IVF Treatment

Objective To evaluate endometrial and subendometrial blood flows measured by vaginal color Doppler ultrasound as a predicator of endometrial receptivity in women undergoing IVF treatment. Methods A total of 119 infertile patients undergoing the first IVF/ICSI-ET cycle were recruited. Three groups were divided according to a color Doppler ultrasound examination performed on the day of hCG injection. Group A, endometrial and subendometrial blood flows were 2 branches and below; group B, endometrial and subendometrial blood flows were between 3 and 4 branches; group C, endometrial and subendometrial blood flows were 5 branches and above. Patients were transferred 1-3 embryos each. Demographic data, ovarian responses, endometrial thickness, PI, RI, development of embryo and IVF result among groups were compared. Results Demographic data, ovarian responses, endometrial thickness, PI, RI and development of embryo among groups have no significant difference. The pregnancy rate of group A was significantly lower than that of group B （P〈0.05） and group C （P〈0.01）. The implantation rate of group A was significantly lower than than of group C （P〈0.01）. There was no significant difference of the rate of pregnancy and implantation between group B and group C （P〉0.05）. Conclusion Endometrial and subendometrial blood flows measured by vaginal color Doppler ultrasound is a good predicator of pregnancy during IVF treatment. A good endometrial and subendometrial blood flows is benefit for the result of IVF.

Assessment of voluntary rhythmic muscle contraction-induced exercising blood flow variability measured by Doppler ultrasound

Given recent technological developments, ultrasound Doppler can provide valuable measurements of blood velocity/flow in the conduit artery with high temporal resolution. In human-applied science such as exercise physiology, hemodynamic measurements in the conduit artery is commonly performed by blood flow feeding the exercising muscle, as the increase in oxygen uptake (calculated as a product of arterial blood flow to the exercising limb and the arterio-venous oxygen difference) is directly proportional to the work performed. The increased oxygen demand with physical activity is met through a central mechanism, an increase in cardiac output and blood pressure, as well as a peripheral mechanism, an increase in vascular conductance and oxygen extraction (a major part of the whole exercising muscles) from the blood. The increase in exercising muscle blood flow in relation to the target workload (quantitative response) may be one indicator in circulatory adjustment for the ac- tivity of muscle metabolism. Therefore, the determination of local blood flow dynamics (potential oxygen supply) feeding repeated (rhythmic) muscle contractions can contribute to the understanding of the factors limiting work capacity including, for instance, muscle metabolism, substance utilization and magnitude of vasodilatation in the exercising muscle. Using non-invasive measures of pulsed Doppler ultrasound, the validity of blood velocity/flow in the forearm or lower limb conduit artery feeding to the muscle has been previously demonstrated during rhythmic muscle exercise. For the evaluation of exercising blood flow, not only muscle contraction induced internal physiological variability, or fluctuations in the magnitude of blood velocity due to spontaneous muscle contraction and relaxation induced changes in force curve intensity, superimposed in cardiac beat-by-beat, but also the alterations in the blood velocity (external variability) due to a temporary sudden change in the achieved workload, compared to the target workload, should be considered. Furthermore, a small amount of inconsistency in the voluntary muscle contraction force at each kick seems to be unavoidable, and may influence exercising muscle blood flow, although subjects attempt to perform precisely similar repeated voluntary muscle contractions at target workload (muscle contraction force). This review presents the methodological considerations for the variability of exercising blood velocity/flow in the limb conduit artery during dynamic leg exercise assessed by pulsed Doppler ultrasound in relation to data previously reported in original research.

Measurement of Liver Size and Intrahepatic Blood Flow of Red-eared Turtles by Color Doppler Ultrasound

In the study, a total of 20 red-eared turtles （ half male and half female） were selected to conduct the measurement of liver size and intrahepatic blood flow of red-eared turtles by color Doppler ultrasound. The results showed that the fight hepatic lobe could be scanned through the right carotid anterior acoustic win- dow, and the left hepatic lobe could be scanned through the left carotid anterior acoustic window, but the vision would be obstructed by the air in trachea. The liver could also be scanned through the left femoral anterior acoustic window and the fight femoral anterior acoustic window when filling of bladder was good. The correla- tion regression analysis suggested that estimated values of liver showed no linear relationship with weight, the longest back curve and the widest back curve. Through the study, the normal indicators for ultrasound examination of red-eared turtle liver were established, in order to provide a reference for examination of turtle liver.

超声B-Flow联合外周血NLR、CRP对颈动脉粥样硬化斑块易损性的诊断效能研究

目的探讨超声二维灰阶血流显像技术(B-Flow)联合外周血中性粒细胞与淋巴细胞比值(NLR)、C反应蛋白(CRP)诊断颈动脉粥样硬化(CAS)斑块易损性的价值。方法纳入2019年2月至2022年8月在天津市永久医院诊查的152例CAS患者为研究对象,均利用颈动脉斑块超声B-Flow和数字减影血管造影(DSA)检查斑块性质,并检测外周血NLR、CRP水平,以DSA结果为“金标准”,将患者分为易损斑块组和稳定斑块组,统计超声B-Flow检查结果,比较两组外周血NLR、CRP水平,分析超声B-Flow、外周血NLR、CRP水平三者单独及联合诊断CAS斑块易损性的价值。结果DSA检查结果显示,152例CAS患者检出66例易损斑块,86例为稳定斑块;超声B-Flow检查出72例易损斑块,80例稳定斑块,以DSA检查结果作为“金标准”,超声B-Flow诊断易损斑块的灵敏度、特异度、准确度分别为84.85%、81.39%、82.89%;易损斑块组外周血NLR、CRP水平均高于稳定斑块组(P<0.05);超声B-Flow联合外周血NLR、CRP水平诊断CAS易损性斑块的灵敏度、特异度、曲线下面积(AUC)分别为98.48、81.39%、0.907,联合诊断的灵敏度高于单独诊断,AUC高于单独诊断(P<0.05),特异度与单独诊断相近。结论超声B-Flow、外周血NLR、CRP均对CAS斑块易损性具有一定的诊断效能,但三者联合诊断效能更好。

A FREQUENCY DOMAIN QUANTITATIVE MEASUREMENT METHOD FOR BLOOD FLOW VELOCITY WITH BIDIRECTIONAL DOPPLERULTRASOUND AVOIDING DOWN-BAND CHANNEL

The up-band signal of the second ultrasonic beam contained reversecomPOnent or blooll now. Using double ultrasonic beam,bidirectional Doppler ultrasound can avoid the use or two kinds or band filters and be simplified into a singlekind or band filter. In order to make the output more accurate,the inrluence of angle effect can be overcome by the table-out method and another special methodcalled cose recorrection.The experiment result is that when the deviation angle varies from-- 18' to +20' the relative error or output is less than 5%.

Measurement of the exercising blood flow during rhythmical muscle contractions assessed by Doppler ultrasound:Methodological considerations

Given the recent technological developments, ultra-sound Doppler can provide valuable measurements of arterial blood flow with high temporal resolution. In a clinical setting, measurements of hemodynamics is used to monitor, diagnose and manage changes in blood velocity profile for cardiac valve disease, relatively large vessel stenosis and other cardiovascular diseases. In health science and preventive medicine for cardiovascular disease with exercise therapy, evaluation of cardiac and vascular function is a useful indicator not only at rest but also during exercise, leading to improved exercise tolerance as well as physical activity. During exercise, the increase in oxygen uptake (calculated as product of arterial blood flow to the exercising limb and the arteriovenous oxygen difference) is directly proportional to the work performed. The increased oxygen demand is met through a central mechanism, an increase in cardiac output and blood pressure, as well as a peripheral mechanism, an increase in vascular conductance and oxygen extraction (major part in the whole exercising muscles) from the blood. Therefore, the determination of the local blood flow dynamics (potential oxygen supply) feeding to rhythmic muscle contractions can contribute to the understanding of the factors limiting the work capacity including, for instance the muscle metabolism, substance utilization and vasodilatation in the exercising muscle. Using non-invasive measures of pulsed Doppler ultrasound the validity of evaluating blood velocity/flow in the fore- arm or lower limb conduit artery feeding to the mus- cle is demonstrated during rhythmic muscle exercise;however the exercising blood velocity profile (fast Fourier transformation) due to muscle contractions is always seen as a physiological variability or fluctuations in the magnitude in blood velocity due to the spontaneous muscle contraction and relaxation induced changes in force curve intensity. Considering the above mentioned variation in blood velocity in relation to muscle contractions may provide valuable information for evaluating the blood flow dynamics during exercise. This review presents the methodological concept that underlines the methodological considerations for determining the exercising blood velocity/flow in the limb conduit artery in relation the exercise model of dynamic leg exercise assessed by pulsed Doppler ultrasonography.

Measurements Of Cerebral Blood Flow in Postasphyxiated Newborns by Color Doppler Imaging（CDI）

Cerebral blood flow of 10 asphyxiated term newborns was continuously measured during the first 7 days of life and compared with that of 10 normal term infants by CDI. Frequency spectrum and blood flow variables in the anterior, middle and posterior cerebral arteries were studied. The results showed evidently lower systolic amplitude in patients than that in normal subjects. End diastolic amplitude was zero in part of vessels, and values of bloed flow variables were all lower in day 1 of the life as compared with the control groups. Frequency spectrum recovered to normal patterns in 9 survived infants in day 2. but blood flow variables recovered to normal by day 7. Values of resistance index (RI) rose to 1 in some vessels of moderate hypoxic ischemic encephalopathy (HIE) infants and stayed at 1 in the severe HIE infants. It is concluded that low CBF plays a key role in brain damage of post-asphyxiated newborns and RI may be an important parameter in the evaluation prognosis.

Voluntary Thigh Muscle Strength with Resection Stump-Dependent Blood Flow and Vasodilation in an Amputated Lower Leg with Total Surface Bearing Prosthesis during Dynamic Knee Extensor: A Case Trial

Background: The magnitude of the hyperemic response due to repeated thigh stump exercise on incremental contraction intensity might be useful information in localized exercise tolerance for devising cardiovascular physical therapy for amputees. The effect of exercise on amputated leg blood flow (LBF) may potentially be altered due to voluntary muscle contractions after loss of the lower leg compared with the healthy leg. Case Presentation: A 57-year-old male patient with Burger disease attempted 3 min unilateral repeat/dynamic knee extensor exercise at a target muscle contraction frequency (1 s thigh muscle contraction and 1 s relaxation, 90 repetitions) with each leg <right transtibial amputated leg (AL) using a total surface-bearing prosthesis (TSB) and left non-AL> at six different contraction intensities (rubber resistance belt). Simultaneous measurement of blood velocity/flow (Doppler ultrasound) in the femoral artery, blood pressure, leg vascular conductance (LVC), and peak muscle strength (PMS) were performed during the 3 min exercise period. The maximum voluntary contraction by one-legged isometric knee muscle contraction was 14.7 kg in non-AL and 7.9 kg in the AL with prosthesis. The relative PMS was defined as “PMS/maximum voluntary contraction × 100 (%)”. Pre-exercise LBF was lower in the AL (200 ± 25 ml/min) than the non-AL (275 ± 74 ml/min). Both the non-AL and AL showed good positive linear relationships between absolute-/relative-PMS and LBF or LVC during 30 s at steady-state before the end of the exercise period. Furthermore, there was also similarity seen in the increase rate in LBF and/or LVC for the incremental relative PMS compared with the absolute PMS. Conclusion: In this case, the muscle strength depended on blood flow increase/vasodilation was seen in this “AL” using a TSB prosthesis for repeated dynamic knee extensor exercise. The present amputee’s limb muscle strengthening with the resection stump closely related to the degree of hyperemia in the amputated limb.

Effects of Norepinephrine on Renal Cortical and Medullary Blood Flow in Atherosclerotic Rabbits

Objective The aim of this study was to explore the effect of norepinephrine(NE)on renal cortical and medullary blood flow in atherosclerotic rabbits without renal artery stenosis.Methods Atherosclerosis was induced in 21 New Zealand white rabbits by feeding them a cholesterol-rich diet for 16 weeks.Thirteen healthy New Zealand white rabbits were randomly selected as controls.After atherosclerosis induction,standard ultrasonography was performed to confirm that there was no plaque or accelerated flow at the origin of the renal artery.Contrast-enhanced ultrasound(CEUS)was performed at baseline and during intravenous injection of NE.The degree of contrast enhancement of renal cortex and medulla after the injection of contrast agents was quantified by calculating the enhanced intensity.Results The serum nitric oxide(NO)level in atherosclerotic rabbits was higher than that in healthy rabbits(299.6±152 vs.136.5±49.5,P<0.001).The infusion of NE induced a significant increase in the systolic blood pressure(112±14 mmHg vs.84±9 mmHg,P=0.016)and a significant decrease in the enhanced intensity in renal cortex(17.78±2.07 dB vs.21.19±2.03 dB,P<0.001)and renal medulla(14.87±1.82 dB vs.17.14±1.89 dB,P<0.001)during CEUS.However,the enhanced intensity in the cortex and medulla of healthy rabbits after NE infusion showed no significant difference from that at baseline.Conclusion NE may reduce renal cortical and medullary blood flow in atherosclerotic rabbits without renal artery stenosis,partly by reducing the serum NO level.

超声评估在子宫内膜容受性判定中的应用

目的 探讨经阴道三维超声在子宫内膜容受性判定中的应用价值。方法 回顾性选取昆明市妇幼保健院2022年4月至2023年6月106例拟行辅助生殖者,所有辅助生殖者在妊娠前均接受经阴道三维超声检测,根据临床妊娠与否分为妊娠组(n=48)和未妊娠组(n=58),运用经阴道三维容积探头,记录2组子宫内膜类型、子宫内膜血流分型、子宫内膜容积、妊娠率、子宫内膜及内膜下血流参数[血流指数(flow index,FI)、血管化指数(vascularization index,VI)、及血管-血流指数(vascular fiow index,VFI)]情况。结果 2组在子宫内膜类型、子宫内膜血流分型、子宫内膜容积方面比较,差异有统计学意义(P <0.05);子宫内膜形态A型妊娠率高于C型,子宫内膜血流分型Ⅲ级妊娠率高于型Ⅰ级,差异有统计学意义(P <0.05);2组在子宫内膜及内膜下FI、VI以及VFI方面比较,差异有统计学意义(P <0.05)。结论 经阴道三维超声技术能够有效评估子宫内膜容受性,预测妊娠结局,为临床治疗方案提供重要依据。

子宫动脉多普勒超声血流成像相关参数与妊娠期高血压产妇妊娠结局的关系

目的 探讨子宫动脉多普勒超声血流成像相关参数与妊娠期高血压产妇妊娠结局的关系。方法 选取80例妊娠期高血压产妇纳入病例组,80例健康产妇纳入健康组,比较两组的子宫动脉多普勒超声血流成像相关参数。比较病例组不同妊娠结局产妇的相关参数,分析不良妊娠结局的危险因素。结果 病例组的子宫动脉RI、 PI、 S/D均高于健康组(P <0.05)。病例组发生不良妊娠结局产妇的子宫动脉RI、 PI、 S/D均高于未发生产妇(P <0.05)。Logistic回归分析显示,子宫动脉RI、 PI、 S/D均为不良妊娠结局发生的独立危险因素(OR>1,P <0.05)。结论 妊娠期高血压产妇的子宫动脉RI、 PI、 S/D显著高于正常产妇,且子宫动脉RI、 PI、 S/D与不良妊娠结局有关,临床中可将多普勒超声检查用于病情诊断及不良妊娠结局风险预测。

自由跤运动员专项训练时的血流限制对其肌肉力量和形态的影响

目的:探讨4周自由跤专项训练时,血流限制对女子自由跤运动员肌肉力量以及身体成分、肢体围度、肌肉厚度的影响。方法:将20名专项训练经历在5年以上的北京队一线女子自由跤运动员随机分为加压组和对照组。两组受试者使用相同的专项训练内容,加压组训练时在上肢或下肢佩戴加压带进行血流限制。比较两组受试者4周训练前后肌肉力量以及身体成分、肢体围度和肌肉厚度的变化。结果:4周训练后,1)与训练前相比,加压组和对照组的身体成分均无显著性变化(P>0.05),但加压组出现骨骼肌量增加、脂肪量减少的趋势,加压组体重增加了0.57%,骨骼肌量增加了4.10%,脂肪量下降了1.48%;2)与训练前相比,加压组右上臂紧张围增加(P<0.05),其余围度指标均无显著性变化(P>0.05),加压组上臂围度增加幅度大于对照组;3)与训练前相比,加压组放松状态下的肱二头肌厚度、放松和紧张状态下的大腿前侧肌肉厚度增加(P<0.05),且放松状态下的肱二头肌和大腿前侧肌肉厚度增加幅度较大(26.59%和22.36%);训练后,加压组放松状态下的肱二头肌厚度、放松和紧张状态下的大腿前侧肌肉厚度高于对照组(P<0.05);4)与训练前相比,加压组左膝屈和右膝伸峰值力矩增加(P<0.05),且加压组增加幅度(6.00%和8.87%)大于对照组(5.42%和0.00%);5)与训练前相比,加压组深蹲、卧推、卧拉的最大静力增加(P<0.05);训练后,加压组的卧推最大静力(70.63 kg)显著高于对照组(51.07 kg)(P<0.05),且加压组提升幅度(9.45%)高于对照组(0.46%)。结论:4周自由跤专项训练结合血流限制干预,在保持运动员体重的同时,提高了上下肢主要肌肉的体积,提高了深蹲、卧推和卧拉等的最大力量和局部关节力量,效果优于传统专项训练。

小儿颈部淋巴管瘤的超声诊断及血流特征分析

目的 分析超声诊断小儿颈部淋巴管瘤的声像图特点及血流特征。方法 选择2016年6月至2019年6月收治的超声疑似颈部淋巴管瘤患儿50例,以手术病理诊断作为金标准,计算超声诊断符合率,分析巨囊型淋巴管瘤、微囊型淋巴管瘤、混合型淋巴管瘤的超声特征及阻力指数、静脉流速、收缩期峰值流速。结果 50例患儿手术病理中,巨囊型淋巴管瘤35例(70.0%),微囊型淋巴管瘤8例(16.0%),混合型淋巴管瘤3例(6.0%),淋巴血管畸形4例(8.0%)。超声诊断符合率为92.0%。巨囊型淋巴管瘤的阻力指数、静脉流速、收缩期峰值流速最高,其次是微囊型淋巴管瘤,最低的是混合型淋巴管瘤,三者间差异均有统计学意义(P<0.05)。结论 超声在小儿颈部淋巴管瘤的诊断中准确性高,为临床医师制定治疗方案提供科学依据。

二维超声联合微血管血流成像对睾丸结核的诊断价值

目的:探讨二维超声联合微血管血流成像(MV-flow)对睾丸结核的诊断价值。方法:选择2023年1月至12月在郑州大学第一附属医院因阴囊疼痛、坠胀,或伴有阴囊肿块就诊,疑似睾丸结核的91例患者为研究对象。均行二维超声检查、彩色多普勒血流显像(CDFI)和MV-flow。以病理结果为金标准,比较二维超声联合MV-flow及二维超声联合CDFI诊断睾丸结核的效能,同时计算血流像素占比。另外选取20例疑似睾丸结核患者,通过MV-flow获取血管指数(VI),采用同类相关系数(ICC)评估MV-flow检测结果的一致性。结果:91例患者中共有80例病理确诊为睾丸结核。二维超声联合MV-flow诊断睾丸结核的敏感度、特异度、准确度分别为96.3%、54.6%和91.2%,高于二维超声联合CDFI(87.5%、18.2%、79.1%)。MV-flow睾丸内血流像素占比高于CDFI[(2.13±0.81)%vs(1.86±0.70)%,P=0.360]。VI在观察者内和观察者间的一致性良好[ICC(95%CI)分别为0.874(0.683~0.950)、0.945(0.860~0.978)]。结论:相比二维超声联合CDFI,二维超声联合MV-flow对睾丸结核的诊断效能更高。

正常胎儿脐静脉血流量Z评分模型的构建及其对小于胎龄儿围生期不良结局的预测价值

目的构建正常胎儿脐静脉血流量(Quv)Z评分模型,并探讨该模型对小于胎龄儿(SGA)围生期不良结局的预测价值。方法(1)纳入862例18~40周正常胎儿建立模型。以腹部超声测量的腹内段Quv作为因变量,孕周为自变量,采用回归分析获得Quv均数及标准差的最佳拟合方程后,根据公式[Z评分=(实际Quv测值-拟合Quv均值)/拟合Quv标准差]建立正常胎儿Quv Z评分模型。(2)另纳入53例正常胎儿(正常组)和109例SGA,并根据围生期有无不良结局将SGA分为不良结局组(n=50)、无不良结局组(n=59)。利用所建立的模型获得3组的胎儿Quv Z评分。通过绘制受试者工作特征曲线分析正常胎儿Quv Z评分预测SGA围生期不良结局的效能。结果(1)正常胎儿的Quv与孕周呈正相关(P<0.05),Quv的均数及标准差相对孕周的最佳拟合方程均为线性方程。根据公式获得正常胎儿Quv Z评分模型:Z评分=(Quv+346.069-20.754×孕周)(/-51.320+4.075×孕周)。正常组胎儿Quv的Z评分呈正态分布,且不随孕周而改变。(2)不良结局组、无不良结局组、正常组的胎儿Quv Z评分依次增加(P<0.05)。(3)正常胎儿Quv Z评分预测SGA围生期不良结局的曲线下面积为0.843,基于最佳截断值-2.06的预测敏感度、特异度、阳性预测值、阴性预测值分别为74.0%、86.4%、82.2%、76.4%。结论所建立的正常胎儿Quv Z评分模型可消除孕周的影响,具有较好的临床适用性。正常胎儿Quv Z评分是预测SGA围生期不良结局较敏感的指标。

颈总动脉流速对创伤合并休克患者容量反应性的评价

目的探讨颈总动脉呼气末及吸气末流速对评估创伤合并休克患者容量反应性的意义。方法前瞻性研究2017年7月—2019年1月上海市浦东新区人民医院重症监护室收治需要机械通气控制呼吸的创伤合并休克患者60例,根据液体复苏后是否具有容量反应性(VR)且扩容前后心输出量(CO)变化是否≥15%将患者分为有反应(VR+组)及无反应(VR-组),各30例。VR+组男性23例,女性7例;年龄18~86岁,平均46.9岁。VR-组男性21例,女性9例;年龄18~90岁,平均46.1岁;采用迈瑞M9便携式多普勒超声取右颈总动脉长轴方向上测量两组患者呼气末最大血流速度(ex-Vmax)、吸气末最大血流速度(in-Vmax)与呼气末平均血流流速(ex-TAmax)、吸气末平均血流流速(in-TAmax),并计算出各自的变异度值:颈总动脉吸呼气末最大血流速度变异度(△Vmax)、吸呼气末平均血流速度变异度(△TAmax),分析不同组别上述数值的变化;绘制受试者工作特征(ROC)曲线,分析以上各项指标在容量反应性评估方面的价值。结果VR+组与VR-组in-Vmax[(71.72±18.67)cm/s vs.(79.47±24.04)cm/s]、in-TAmax[(40.67±11.44)cm/svs.(46.44±15.84)cm/s]比较无明显差异,但ex-Vmax[(61.00±17.84)cm/s vs.(76.86±25.28)cm/s]、ex-TAmax[(34.83±11.01)cm/s vs.(44.66±15.43)cm/s]比较差异有统计学意义(P<0.05)。VR+组与VR-组△Vmax(19.42%±14.18%vs.5.09%±13.59%)、△TAmax(18.19%±11.63%vs.4.29%±7.57%)比较差异有统计学意义(P<0.001)。ex-Vmax与ex-TAmax对创伤合并休克患者容量评估的ROC曲线下面积分别为0.695和0.678,而△Vmax与△TAmax的ROC曲线下面积均>0.800,分别是0.803和0.863,提示△Vmax、△TAmax对于创伤合并休克患者容量的评估更敏感。结论呼气末颈总动脉最大血流流速及平均血流流速、吸呼气末最大血流流速差异度及平均血流流速变异度均可用来评估机械通气创伤合并休克患者的容量反应性,且吸呼气末最大血流流速变异度及平均血流流速变异度对容量反应性的评估效果更佳。

超微血流成像在新生儿室管膜下疾病的应用

目的探讨超微血流成像技术对新生儿颅脑室管膜下疾病(出血及囊肿)的诊断价值。方法应用超声检查新生儿颅脑,将尾状核头部和丘脑交界处室管膜下出现强回声团或囊性回声标记为阳性指标,将患儿分为三组:正常组、强回声组和囊肿组,分别应用超微血流成像技术观测新生儿尾状核头部和丘脑交界处室管膜区的血流情况,并对病变组(强回声组和囊肿组)进行动态观察以明确诊断并随访。结果观察正常组30例患儿,室管膜下围绕脑室可见星点状及带状血流信号,血流信号丰富程度随侧脑室及脉络丛强回声增多而增丰;强回声组18例,其强回声与脉络丛回声相似,16例(16/18)超微血流成像显示此区域可以见丰富血流信号,其血流信号与脉络丛显示相似,并且其血流在室管膜下与远端脉络丛相连,其中2例(2/18)强回声内部未探及血流信号,后期随访转为囊状回声;囊肿组11例,室管膜下囊肿周边可见丰富血流信号,囊肿周边随强回声团增加其血流显示更丰富,8例(8/17)囊肿内可见血流信号。结论超微血流成像可明确室管膜下区早期病变性质,可以动态观测疾病进展及推测预后,为临床提供更全面的诊断信息,或许此技术的应用将成为室管膜下出血诊断的金标准。

基于多频脉冲采样的血流速度估计方法

传统双模超声技术相较于新兴技术更具实现可穿戴化的潜力。在进行脉冲多普勒血流速度估计时,双模超声需同时发射B模式脉冲进行成像定位,这要求B模式脉冲和多普勒脉冲共享采样时间。采用基于单频多普勒脉冲的稀疏间隔发射方式可以解决这一问题,但常见的稀疏发射排布方式(如嵌套发射、互质发射等)存在采样时间窗较长的缺点,特别是在血流速度变化明显的情况下存在时间分辨率不足的问题。此外,长时间窗包含了较多的血流速度分量,容易由于稀疏采样引起伪影,从而影响血流速度估计的准确性。因此,文中提出了一种基于多频脉冲采样的新型血流速度估计方法。首先,构建了多频脉冲采样的回波模型,并对该模型进行推导,证明了在频率衰减平稳假设下,该数学模型等价于单频多普勒脉冲稀疏发射方式,即多频脉冲采样可以通过较短的时间窗实现类似于基于单频脉冲采样模式的长时间窗的性能,从而提高血流速度谱的时间分辨率和估计精度;然后,提出了两种可用于多频脉冲采样模式的血流速度谱的构建方法,分别为复杂度较低的BMUSIC算法和伪影抑制效果较佳的VMUSIC算法。基于FieldⅡ仿真数据和人体实测数据的实验结果表明:相较于单频多普勒脉冲稀疏发射方式,文中方法不仅可以采用较短的时间窗提升血流速度谱的时间分辨率,还可以获得连续、清晰、精度较高且伪影抑制效果较佳的血流速度估计结果;在人体实测数据实验中,由于实验条件所限,文中方法无法实现非整数倍频,未能充分展现VMUSIC算法的性能优势。