49 例先天性胎儿心脏疾病的静脉导管血流频谱分析

目的：不同的胎儿先天性心脏疾病通过不同的作用机制影响到胎儿心脏功能,会引起胎儿体内血循环的不同改变。静脉导 管是胎儿血循环中重要的组成,也会随之出现相应的频谱改变。通过对49 例合并先天性心脏疾病胎儿的静脉导管血流频谱及参 数进行分析,研究胎儿不同类型心脏疾病对静脉导管（DV）血流频谱的影响。方法：选取2009 年1 月至2012 年12 月间我们在产 前超声检查中发现的49 例合并先天性心脏疾病的胎儿,分别测量DV血流频谱并进行参数分析,根据DV频谱是否正常分为两 组。结果：DV频谱正常组有29 例(59.18%),表现为S 波、a 波的流速和方向正常,PVIV 及DVRI指标位于正常范围。DV频谱异 常组有20 例,表现为S波流速降低、a 波缺失或反向,PVIV 及DVRI升高。结论：DV血流频谱和参数是评价胎儿心功能的良好 指标。不同种类胎儿心脏发育异常对胎儿心功能影响的作用机制不同,其DV频谱也有着不同改变。通过对DV频谱的波形和参 数分析,了解胎儿心脏异常的病生理机制,评价其严重程度和预后,这对于指导临床诊疗有着重要意义。     

四维彩超技术在筛查胎儿先天性心脏病的应用价值分析

目的:探讨四维彩超技术在筛查胎儿先天性心脏病的应用价值。方法:择取我院2012年3月至2014年3月收治的行产前筛查的300例产妇为研究对象,采用四维彩色多普勒超声择取心脏三血管、四腔观、肺动脉分叉、上下腔静脉回流、动脉导管弓、主动脉弓等常规切面,予以胎心各腔血流及胎心率等多项检测,对胎儿是否存在先心病进行综合诊断,并综合胎儿大体解剖状况,与病理诊断及二维超声检查结果进行对比。结果:四维彩超检出率为6.67%,正确率为90.00%;二维超声检出率为6.00%,正确率为83.33%,两组比较差异具有统计学意义(P0.05)。结论:四维彩超技术在筛查胎儿先天性心脏病中具有至关重要的应用价值,有助于指导胎儿先天性心脏病早期治疗,保证患儿预后,值得临床借鉴。     

49例先天性胎儿心脏疾病的静脉导管血流频谱分析

目的：不同的胎儿先天性心脏疾病通过不同的作用机制影响到胎儿心脏功能,会引起胎儿体内血循环的不同改变。静脉导管是胎儿血循环中重要的组成,也会随之出现相应的频谱改变。通过对49例合并先天性心脏疾病胎儿的静脉导管血流频谱及参数进行分析,研究胎儿不同类型心脏疾病对静脉导管（DV）血流频谱的影响。方法：选取2009年1月至2012年12月间我们在产前超声检查中发现的49例合并先天性心脏疾病的胎儿,分别测量DV血流频谱并进行参数分析,根据DV频谱是否正常分为两组。结果：DV频谱正常组有29例（59.18%）,表现为S波、a波的流速和方向正常,PVIV及DVRI指标位于正常范围。DV频谱异常组有20例,表现为S波流速降低、a波缺失或反向,PVIV及DVRI升高。结论：DV血流频谱和参数是评价胎儿心功能的良好指标。不同种类胎儿心脏发育异常对胎儿心功能影响的作用机制不同,其DV频谱也有着不同改变。通过对DV频谱的波形和参数分析,了解胎儿心脏异常的病生理机制,评价其严重程度和预后,这对于指导临床诊疗有着重要意义。     

产前经腹灰阶联合彩色血流超声多参数对胎盘植入性疾病的诊断效能研究

摘要 目的：探究产前经腹灰阶联合彩色血流超声多参数对胎盘植入性疾病的诊断效能。方法：2019年11月-2021年12月于我院收治的产前超声诊断为前置胎盘的孕妇共计62例,其中44例超声诊断合并了胎盘植入的孕妇。所有孕妇产前均进行经腹灰阶检查、经腹彩色超声检查和二者联合检查胎盘植入性疾病,通过分析胎盘植入性疾病筛查结果,评价产前超声经腹灰阶联合彩色血流超声多参数对胎盘植入性疾病的筛查效能。结果：（1）通过灰阶超声诊断检出胎盘植入的灵敏度为73.42 %,特异度为86.54 %;（2）通过彩色超声诊断检出胎盘植入的灵敏度为76.89%,特异度为89.07 %;（3）经腹灰阶联合彩色血流超声多参数诊断检出胎盘植入的灵敏度为87.79 %,特异度为90.36 %;（4）经腹灰阶检查、经腹彩色超声检查和二者联合检查对胎盘植入性疾病筛查阳性率分别为56.45 %、62.90 %和67.74 %,二者联合检查对产前胎盘植入性疾病筛查阳性率显著高于经腹灰阶检查和经腹彩色超声检查（P<0.05）。（5）二者联合检查的敏感度为72.26 %,特异度为90.54 %,阳性比为95.55 %,诊断比值比为78.89 %。结论：产前经腹灰阶联合彩色血流超声多参数对胎盘植入性疾病的诊断有较高的灵敏度和特异度,值得临床推广应用。     

Evaluation of ultrasonography effectiveness in prostate cancer detection

The database of examining 624 patients aged 49-85 were analyzed to define the diagnostic effectiveness of gray-scale, color and power Doppler transrectal ultrasonography (TRUS). Among them there are 473 (75.8%) cancer patients and 151 (24.2%) benign prostate diseases patients. All the patients underwent a transrectal ultrasound examination with multifocal biopsy. The gray-scale, color and power Doppler transrectal ultrasound examination has the diagnostic accuracy of 75,3%. At this the effectiveness of the method increases with the Gleason sum growing.     

The usefulness of contrast-enhanced sonography in the differential diagnostic of adrenal tumors

INTRODUCTION: The occurrence of gland tumors causes significant clinical problem. Non hormone-secreting tumors provide the most complicated diagnostic difficulties. The application of contrast-enhanced sonography could improve the vessels visualization and point out characteristic features of benign and malignant changes. The authors believe that this new method make possible the differential adrenal tumor diagnostic process more precise and increase the specificity of ultrasonography in the recognition of benign and malignant tumors. The aim of this study was to define the usefulness of contrasting agent Levovist in differential diagnostics of adrenal tumors and its influence on sensitivity and specificity of ultrasound examination and to establish patients qualification criteria for surgical procedures. MATERIAL AND METHODS: Ultrasound examinations were made with the use of digital devise by GE Voluson 740, probe 4-6 mHz with Doppler options and volumetric probe 3D according to the following protocol: 26 patients with recognized adrenal tumor were qualified for the examination. Patients in the first stage of tumor vascularization had Doppler examination with color (CD) and power Doppler (PD). Three-dimensional ultrasonography was used to improve visualization of vascularization. In the final phase of the examination the patients were administrated of Levovist in the recommended by the producer dose: 2.5 g in the concentration of 400 mg/l. RESULTS: 26 cases of adrenal gland tumours were subjected to analysis. In standard ultrasonographic examination focal changes in 25 patients were hipoechogenic focuses and in one case the focus was hyperechogenic. Heterogeneity of focuses was observed in 16 cases. In Doppler examination with color (CD) and power Doppler (PD) vascular blood flow was revealed within 12. After using contrasting agent Levovist vascular blood flow was achieved in 4 additional cases, which constituted 61%. CONCLUSIONS: 1. 3D ultrasound could be useful in cases of big adrenal tumors--over 3 cm diameter after application of ultrasound contrast agents. 2. The use of Levovist in Doppler examination improves the visualization of tumor vascularization. However, it is impossible to differentiate benign from malignant tumors unequivocally.     

Doppler echocardiographic estimation of left ventricular end-diastolic pressure after MI in rats

The spectral Doppler mitral flow pattern, alone or combined with tissue Doppler mitral annulus velocity, can be used to predict left ventricular (LV) filling pressure in humans, whereas invasive hemodynamic measurements are still required in the rat. This study was undertaken to assess whether LV end-diastolic pressure (LVEDP) can be estimated using Doppler echocardiography in the rat after myocardial infarction (MI). Thirty-seven rats (23 rats with MI after left coronary artery ligation and 14 sham-operated rats) were evaluated 3 mo after surgery with echo-Doppler and invasive hemodynamic measurements. Pulse wave spectral Doppler at the mitral valve tip was used to measure the E wave, the E wave deceleration time (DT), and the A wave; spectral Doppler tissue imaging was used to measure the early diastolic lateral mitral annulus velocity (E(a)). We found weak correlations between LVEDP and the peak velocity of the early mitral inflow (E), E/peak velocity of the late mitral inflow, and DT, and strong correlations with E(a) and especially with E/E(a) [R(2) = 0.89, LVEDP (in mmHg) = 0.987E/E(a) - 4.229]. Longitudinal followup of a subgroup of rats with MI revealed a marked rise of E/E(a) between days 7 and 21 in rats with heart failure only. We conclude that Doppler echocardiography can be used for serial assessment of LV diastolic function in rats with MI.     

高危孕妇胎儿缺氧与彩色多普勒超声结合四维超声检查的相关性研究

摘要 目的：探讨与研究高危孕妇胎儿缺氧与彩色多普勒超声结合四维超声检查的相关性。方法：2018年2月到2020年1月在本院进行建档分娩的高危孕妇108例作为研究对象,都给予彩色多普勒超声结合四维超声检查,记录影像学特征,判定胎儿缺氧发生情况并进行相关性分析。结果：在高危孕妇108例中,发生宫内缺氧28例（宫内缺氧组）,发生率为25.9 %;宫内缺氧组的大脑中动脉、脐动脉的阻力指数（RI）、搏动指数（PI）、收缩期峰值流速舒张期流速比值（S/D）均高于非宫内缺氧组（P<0.05）;宫内缺氧组的上腔静脉血流心室收缩期峰值流速（S波）、心房收缩期速度（A波）、心室舒张期峰值流速（D波）均高于非宫内缺氧组（P<0.05）;高危孕妇108例中,Spearsman分析显示大脑中动脉、脐动脉的RI、PI、S/D以及上腔静脉血流S、D、A均与宫内缺氧都存在相关性（P<0.05）;logistic多因素回归分析显示：大脑中动脉、脐动脉的S/D与上腔静脉血流S、A为导致胎儿缺氧的主要影响因素（P<0.05）。结论：高危孕妇胎儿缺氧与彩色多普勒超声结合四维超声检查特征具有相关性,彩色多普勒超声结合四维超声可作为检查胎儿缺氧的可行、简单无创、方便快捷的方式,具有极高的应用价值。     

Pressure pulses and flow velocities in central veins of the anesthetized sheep fetus

The pressure drop and pressure pulses in the isthmus of the ductus venosus (DV) in fetal sheep have not been measured directly and related to flow. In eight acutely anesthetized fetal sheep, a 3-Fr tip pressure transducer (TP) was inserted from the external jugular into the umbilical vein (UV). Ultrasound Doppler flow velocities, TP position, and intravenous pressures were recorded in the UV, DV, and inferior vena cava (VC) while the TP was withdrawn. Flow was steady in the UV, but small pressure fluctuations (<0.4 mmHg) could be detected. Time-averaged pressure dropped 1.9 mmHg (mean; 0.5-3.3 mmHg 95% confidence interval) across the DV isthmus. Pressure pulses increased from 1.7 mmHg (mean; 1.2-2.1 mmHg 95% confidence interval) in the DV to 3.9 mmHg (mean; 1.8-6.0 mmHg 95% confidence interval) in the inferior VC. The pressure wave from the heart arrived later [0.053 s (mean; 0.025-0.080 s 95% confidence interval)] in the isthmus of the DV than in the diaphragmatic inferior VC, indicating a wave velocity of approximately 1.1 m/s. At all locations, pressures and flow velocities were inversely related.     

Blood flow in ductus venosus in early uncomplicated pregnancy

The ductus venosus is the very important part of fetal venous circulation. It plays a central role in return of venous blood from the placenta. This unique shunt carries well-oxygenated blood from the umbilical vein through the inferior atrial inlet on its way across the foramen ovale. Using Doppler ultrasound, it is possible to assess the blood flow in fetal vessels including ductus venosus. It is observed, in animal and human studies, that the typical waveform for blood flow in ductus venosus in early pregnancy can be different depending on numerous conditions e.g. fetal karyotype. This study is performed to assess the physiologic parameters of blood flow in ductus venosus in uncomplicated early pregnancy. Material and Methods: 404 women were examined between 11+0 and 13+6 weeks (+ days) of gestation by ultrasound. Fetal crown-rump length (CRL) was measured to assess the gestational age. The assessment of risk of fetal abnormalities was based on nuchal translucency (NT) measurement. The ductus venosus blood flow with color and spectral Doppler was obtained in all patients. The following features were assessed: pulsatility index (PI), and direction of flow (positive/negative) during atrial contraction (wave A). All cases were followed up to 22 weeks of gestation when the control scan was performed. Results and conclusions: 30 cases were excluded from the uncomplicated group due to: high risk of fetal abnormalities, fetal loss, confirmed fetal abnormalities and utero-placental pathology. 374 women were considered as uncomplicated pregnancy. In both uncomplicated and complicated groups the mean values for pulsatility index (PI) were established. The mean PI value in uncomplicated pregnancies was: 0.91 (SD +/- 0.32). No significant differences between groups were noticed. In 370 cases of uncomplicated pregnancy the A wave direction was positive but in 1.1% of cases the reverse flow in atrial contraction was observed.     

多切面法联合彩色多普勒超声在胎儿先天性心脏病诊断中的应用

目的:探讨多切面法联合彩色多普勒超声在胎儿先天性心脏病(congenital heart diseases,CHD)诊断中的应用价值。方法:采用多切面法联合彩色多普勒超声对2015年5月~2016年7月300例胎儿进行CHD筛查,并与随访的产后超声或尸解结果作对照。结果:300例胎儿经产前超声联合多切面法检出CHD胎儿20例,检出率为6.7%,经产后超声或尸解确诊14例:三尖瓣下移畸形1例,室间隔完整型完全性大动脉转位1例,完全性房室间隔缺损1例,室间隔完整型肺动脉瓣闭锁1例,双流入型单心室1例,共同动脉干Ⅰ型2例,单纯室间隔缺损2例,法洛氏四联症2例,主动脉弓缩窄1例,肺动脉瓣轻度狭窄1例,二尖瓣闭锁并共同动脉干1例;误诊为单纯室间隔缺损1例,误诊为法洛氏四联症1例,病例流失4例。产前超声联合多切面法对有、无高危因素的检出率分别为3.79%、13.48%,比较有统计学意义(P0.05)。产前超声联合多切面法诊断CHD的灵敏度为100%、特异度为99.66%、阳性预测值为80.00%、阴性预测值为100%。结论:多切面法联合彩色多普勒超声在胎儿CHD诊断中具有较高的应用价值。     

彩色多普勒超声检查对胎儿颅内畸形筛查的应用价值及染色体异常分析

摘要 目的：探讨彩色多普勒超声检查对胎儿颅内畸形筛查的应用价值,并进行染色体异常分析。方法：选择2016年2月至2019年5月本院收治的进行胎儿颅内畸形筛查的高危孕妇120例,所有孕妇都给予彩色多普勒二维超声与三维超声筛查,对超声筛查异常者进行染色体异常分析,记录预后情况。结果：在120例孕妇中,二维超声诊断为胎儿颅内畸形12例,三维超声诊断为13例(预后都确诊为胎儿颅内畸形)。染色体核型筛查检出胎儿颅内畸形12例,其中21-三体综合征8例,18-三体综合征3例,13-三体综合征1例。确诊为胎儿颅内畸形的孕妇超声NT值都显著高于非胎儿颅内畸形孕妇,差异都有统计学意义(P<0.05)。孕妇选择终止妊娠10例,选择继续妊娠3例,继续妊娠3例胎儿都最终死亡。结论：产前彩色多普勒超声结合染色体核型在胎儿颅内畸形筛查中具有很高的价值,两者可互相补充,共同发挥诊断与预后评估价值。     

对比分析四维容积超声及彩色多普勒超声在胎儿肺静脉异位引流诊断中的应用

摘要 目的：对比分析四维容积超声及彩色多普勒超声在胎儿肺静脉异位引流（APVC）诊断中的应用价值。方法：采用回顾性分析方法,2019年1月到2022年1月选择在本院进行诊治的胎儿肺静脉异位引流孕妇60例作为研究对象,都给予四维容积超声及彩色多普勒超声,记录影像学特征并判断诊断价值。结果：在60例孕妇中,彩色多普勒超声检查判断为胎儿肺静脉异位引流51例,诊断敏感性为85.0 %;四维容积超声检查判断为胎儿肺静脉异位引流59例,诊断敏感性为98.3 %,四维容积超声检查对胎儿肺静脉异位引流的诊断敏感性明显高于彩色多普勒超声检查（P<0.05）。彩色多普勒超声检查与四维容积超声检查诊断的特异性都为100.0%。在60例孕妇中,判断为胎儿肺静脉异位引流心上型32例,心下型28例;心上型的肺静脉引流途径为肺静脉-垂直静脉-右上腔静脉22例、肺静脉-垂直静脉-左上腔静脉10例,心下型的肺静脉引流途径为肺静脉-垂直静脉-左头臂静脉-右上腔静脉6例、肺静脉-垂直静脉-门静脉22例。合并心脏畸形32例,合并畸形率为53.3 %;有51例孕妇终止妊娠,9例孕妇继续妊娠,其中8例未经治疗者新生儿期死亡,1例在3月龄死亡。结论：相对于彩色多普勒超声,四维容积超声在胎儿肺静脉异位引流诊断中的应用可提高诊断敏感性,可有效反映肺静脉回流情况,可指导临床进行早期干预。     

产前超声在中孕期胎儿严重先天性心脏病筛查中的应用

目的:探究产前超声检查在中孕期胎儿严重先天性心脏病(CHD)筛查中的应用。方法:选择2012年1月至2014年1月在我院妇产科进行产前常规超声检查的孕妇12076例,年龄22-41岁,平均(28.6±8.3)岁,孕周20-36周,平均(25.2±6.7)周。将符合纳入排除标准的孕妇8953例作为研究对象,其中初产妇6023例,经产妇2930例。对纳入研究的孕妇行彩色多普勒超声检查,并对妊娠结局进行追踪,将确诊情况与筛查结果进行比较分析。结果:产前彩色多普勒超声诊断出胎儿CHD38例,经尸检或新生儿彩色多普勒超声检查均确诊为CHD,对胎儿期未筛查出CHD的孕妇进行新生儿彩色多普勒超声检查,确诊4例,产前超声检查胎儿CHD检出率为90.48%(38/42),检出准确率100%(38/38)。结论:彩色多普勒超声筛查孕中期胎儿CHD,灵敏度和特异性高,安全无创伤,操作简便快速,值得推广为产前筛查的首选方法。     

An assessment of ductus venosus tapering and wave transmission from the fetal heart

Pressure and flow pulsations in the fetal heart propagate through the precordial vein and the ductus venosus (DV) but are normally not transmitted into the umbilical vein (UV). Pulsations in the umbilical vein do occur, however, in early pregnancy and in pathological conditions. Such transmission into the umbilical vein is not well understood. In particular, the effect of the impedance changes in the DV due to its tapered geometry is not known. This paper presents a mathematical model that we developed to study the transmission of pulsations, originating in the fetal heart, through the DV to the umbilical vein. In our model, the tapered geometry of the DV was found to be of minor importance and the only effective reflection site in the DV appears to be at the DV inlet. Differences between the DV inlet and outlet flow were also found to be minor for medium to large umbilical vein–DV diameter ratios. Finally, the results of a previously proposed lumped model were found to agree well with the present model of the DV–umbilical vein bifurcation.     

A new technique for the identification of respiratory sinus arrhythmia in utero

Fetal heart rate (FHR) monitoring forms the basis of routine fetal assessment, particularly short-term variability in the interbeat interval which can be difficult to interpret. Respiratory sinus arrhythmia (RSA), the change in heart rate in response to breathing, contributes to short-term variability, and the presence of RSA in utero may reflect the functional integrity of the central nervous system. This paper describes the use of Doppler ultrasound to derive the required measures of fetal heart rate and fetal breathing movements and spectral analysis to identify RSA. Cases are presented to illustrate the results obtained both in the presence and absence of RSA.     

MicroPure Imaging for the Evaluation of Microcalcifications in Gouty Arthritis Involving the First Metatarsophalangeal Joint: A Preliminary Study

Objective

To assess the value of MicroPure, a new ultrasound image processing technique, in identifying microcalcifications (formed by monosodium urate crystals) in the first metatarsophalangeal joints attacked by gout compared to gray-scale ultrasound images.

Materials and Methods

Thirty-six patients who fulfilled the study inclusion criteria underwent gray-scale ultrasound and MicroPure examinations of the first metatarsophalangeal joints attacked by gout. Static images of the target areas were acquired using gray-scale ultrasound and MicroPure. Two independent and blinded investigators analyzed the images to determine the number of microcalcifications and to score for image quality and artifacts.

Results

The two investigators observed significantly more microcalcifications with MicroPure compared to gray-scale ultrasound (ρ<0.001). The level of agreement between the investigators consistently increased from gray-scale ultrasound to MicroPure imaging (gray-scale interclass correlation coefficient of 0.69 vs. MicroPure interclass correlation coefficient of 0.81). One investigator preferred the MicroPure image quality over gray-scale ultrasound (ρ<0.001), but the other investigator disagreed (ρ<0.001). Both investigators observed fewer artifacts with MicroPure than with gray-scale ultrasound (ρ<0.009).

Conclusion

MicroPure imaging identified significantly more microcalcifications than gray-scale ultrasound.     

Role of ductus venosus in distribution of umbilical blood flow in human fetuses during second half of pregnancy

Color Doppler sonography was used to study umbilical and ductus venosus (DV) flow in 137 normal fetuses between 20 and 38 wk of gestation. Hepatic flows were also evaluated. In all parts of the venous circulation examined, blood flow increased significantly with advancing gestational age. The weight-specific amniotic umbilical flow did not change significantly during gestation (120 +/- 44 ml. min(-1). kg(-1)), whereas DV flow decreased significantly (from 60 to 17 ml. min(-1). kg(-1)). The percentage of umbilical blood flow shunted through the DV decreased significantly (from 40% to 15%); consequently, the percentage of flow to the liver increased. The right lobe flow changed from 20 to 45%, whereas the left lobe flow was approximately constant (40%). These changes are related to different patterns of growth of the umbilical veins and DV diameters. The present data support the hypothesis that the DV plays a less important role in shunting well-oxygenated blood to the brain and myocardium in late normal pregnancy than in early gestation, which leads to increased fetal liver perfusion.     

Dose-dependent disintegration of human endothelial monolayers by contrast echocardiography

Biological effects on endothelium induced by contrast ultrasound (US) may be relevant for transferring drugs into the tissue. An in vitro tissue-mimicking phantom was developed to simulate clinical precordial echocardiography of three modalities (two-dimensional (2DE), pulsed wave (PW), and Power Doppler echocardiography) with gradual increases of acoustic output (mechanical index (MI) 0.0-1.6 and thermal index soft tissue (TIS) 0.0-1.3, respectively; transmit-frequency 1.8 MHz in second harmonic mode (SHI) by 2DE, 1.8 MHz for PW-Doppler, and 3.2 MHz for Power Doppler) as well as contrast agent (CA) concentrations (0.002-4 mg/mL Levovist). Disintegration of the endothelial monolayer was quantitatively analyzed by counting intercellular gaps in light microscopy. No gaps were observed in CA application without sonication. Only few gaps appeared at sonication without CA application in 2DE at MI=1.6 and in PW- and Power Doppler at TIS > or =0.4 and MI > or =0.4. The number of gaps increased significantly with the gradual increase of US output and to a comparably lesser but also significant extent with CA concentrations. Diagnostic contrast echocardiography may induce endothelial disintegrations dependent on US output as well as on CA concentrations. This aspect might be helpful in further in vivo series on local drug delivery.     

Measurement of Thermal Effects of Doppler Ultrasound: An In Vitro Study

Objective

Ultrasound is considered a safe imaging modality and is routinely applied during early pregnancy. However, reservations are expressed concerning the application of Doppler ultrasound in early pregnancy due to energy emission of the ultrasound probe and its conversion to heat. The objective of this study was to evaluate the thermal effects of emitted Doppler ultrasound of different ultrasound machines and probes by means of temperature increase of in-vitro test-media.

Methods

We investigated the energy-output of 5 vaginal and abdominal probes of 3 ultrasound machines (GE Healthcare, Siemens, Aloka). Two in-vitro test objects were developed at the Center for Medical Physics and Biomedical Engineering, Medical University Vienna (water bath and hydrogel bath). Temperature increase during Doppler ultrasound emission was measured via thermal sensors, which were placed inside the test objects or on the probes’ surface. Each probe was emitting for 5 minutes into the absorbing test object with 3 different TI/MI settings in Spectral Doppler mode.

Results

During water bath test, temperature increase varied between 0.1 and 1.0°C, depending on probe, setting and focus, and was found highest for spectral Doppler mode alone. Maximum temperature increase was found during the surface heating test, where values up to 2.4°C could be measured within 5 minutes of emission.

Conclusions

Activation of Doppler ultrasound in the waterbath model causes a significant increase of temperature within one minute. Thermally induced effects on the embryo cannot be excluded when using Doppler ultrasound in early pregnancy.