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Objective:To investigate the accuracy and reproducibility of a new method, Automatic Measurement of Arterial Stiffness(AMAS) system, for arterial stiffness automatic measurement based on regional pulse wave velocity (PWV).Methods:A total of 30 hypertensive patients who were hospitalized in the Department of Cardiology in Tangdu Hospital, Air Force Military Medical University from September 1 to 30, 2019 were enrolled as hypertensive group, while 30 healthy participants at the same time were collected as healthy group. Carotid-femoral PWV (cfPWV) was measured in all subjects by two independent observers using the conventional manual method and the AMAS system. The measurements were compared and the agreement was analyzed.Results:There was no significant difference of cfPWV between AMAS system and the manual method, and the intraclass correlation coefficient was 0.953 (95% CI=0.922-0.971). Bland-Altman plots showed good agreement [mean difference: -(0.08±0.40)m/s; limit of agreement: -0.87-0.71 m/s]. Time consumption for cfPWV measurement using the AMAS system was significantly less than that of conventional manual method, saving about 70% of the time. The cfPWV measured by AMAS showed good intra- and inter-observer reproducibility. Conclusions:AMAS system is accurate and reproducible in measuring arterial stiffness. It may provide a noninvasive, rapid, reliable approach for arterial stiffness evaluation in clinical settings.
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Objective:To explore the feasibility and accuracy of three-dimensional (3D) modeling methods based on ultrasound imaging data for normal and abnormal fetal cardiac structures, and to construct a methodology system for 3D printing of fetal heart based on ultrasound.Methods:A total of 93 fetuses examined in Tangdu Hospital of Air Force Military Medical University from January to December 2019 were selected. Fetal echocardiography was obtained using spatio-temporal image correlation (STIC). Ninety-three hearts were 3D modeled by blood flow modeling, blood pool modeling and cavity modeling, and printed by stereolithography technique. The data measured on the 3D digital models and 3D printed solid models were compared with the corresponding fetal echocardiographic images respectively in order to evaluate the accuracy of the modeling methods.Results:The fetal cardiac blood flow models based on Doppler flow image data showed the malformation and trend of small blood vessels. The fetal cardiac structure models printed based on blood pool modeling displayed the malformation of heart and large blood vessels. Models printed based on cavity modeling method accurately displayed valve and structural defects.For 83 normal fetal hearts, the long diameters of left and right ventricles measured on echocardiography [(15.3±1.9)mm, (13.2±1.9)mm] were compared with those measured on digital models [(15.1±1.9)mm, (12.9±1.9)mm] and 3D printed models[(15.1±1.9)mm, (13.0±1.9)mm], respectively, and there were no significant differences between any two groups of them ( P>0.05). Bland-Altman showed good consistency for all measurements within and between operators. Conclusions:The three modeling methods, including blood flow modeling, blood pool modeling and cavity modeling, have their own advantages in displaying different types of fetal heart malformations. Appropriate modeling methods should be selected for 3D modeling and printing to make up for the limitations of single modeling method. The consistency between measurements on 3D models and those on echocardiography is high, and the repeatability between operators is good.
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Objective:To investigate the application of ultrasound imaging in evaluating the curative effect of patients with nutcracker syndrome (NCS) treated with three-dimensional(3D) printing extravascular titanium stents.Methods:From December 2015 to December 2018, a total of 41 NCS patients enrolled in the Second Affiliated Hospital of the Air Force Military Medical University to receive 3D-printing extravascular titanium stents treatment were included in this study. Ultrasound and CT angiography (CTA) were performed before and 1 week after operation to evaluate the compression of left renal vein and related hemodynamic changes.Results:Before the operative, the ultrasound examination showed that the angle between the abdominal aorta and superior mesenteric artery was (21.29±4.53)°, which was significantly improved in 1 week after treatment [(47.42±7.45)°, P<0.001]. Left renal vein was significantly compressed before treatment, with the smallest inner diameter of (1.51±0.49)mm and its peak blood flow velocity was (143.92±50.40)cm/s. Postoperative ultrasound images showed the significant expansion of left renal vein and no high velocity blood flow was observed. Ultrasound examination also showed that the diameter of left renal vein at renal hilum, blood flow velocity at renal hilum and inner diameter of spermatic vein were significantly improved after treatment ( P<0.001). Similar to ultrasound results, CTA also found that the angle between abdominal aorta and superior mesenteric artery increased significantly after treatment[(17.59±4.56)° vs (52.27±9.01)°, P<0.001]. CTA also showed the left renal vein was compressed before treatment, with the smallest inner diameter of (2.09±0.86)mm, and it was significantly expanded after operation. The inner diameter of left renal vein at renal hilum was also significantly reduced after treatment ( P<0.001). Conclusions:Ultrasound imaging can effectively evaluate the LRV compression and related hemodynamic changes before and after 3D printed stent implantation treatment in NCS patients and provide a reliable method to evaluate its clinical efficacy for these patients.
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Objective To explore the mechanism of intrathoracic pressure(ITP) influncing cardiac function and facilitate noninvasive determination of ventricular pressure theoretically.Methods With Valsalva and Mueller maneuver,two-dimension images of standard long axis views and the cross-sectional views were recorded in 20 volunteers,aged from 18 to 45 years,at the specific ITP levels(including-20 mmHg、-10 mmHg、0 mmHg、+ 10 mmHg and + 20 mmHg).The subjects were instructed to mantain for at least 10 s,and three successive measurements were recorded and averaged.The stroke volume(SV) and radius of curvature(R) were obtained from further off-line analysis.Results With the ITP maintaining at -20 mmHg,-10 mmHg,0 mmHg(end expiration),+ 10 mmHg and + 20 mmHg respectively,the corresponding radiuses of curvature were (2.35 ±0.24)cm,(2.25 ± 0.23)cm,(2.14 ± 0.21)cm,(2.02 ± 0.21) cm,(1.93 ± 0.19) cm,there were statistically significances between two groups (P =0.006,0.031,0.005 and ＜0.001,respectively].When the ITP were at 0 mmHg(end expiration),+ 10 mmHg and + 20 mmHg,the stroke volume were (71.54±8.81)ml,(73.20±9.52)ml and (78.81± 14.61)ml (P =0.674,0.135).When the intrathoracic pressure decreased from 0 mmHg to-20 mmHg,the stroke volume were (78.81±14.61)ml,(68.28 ±9.28)ml and (59.69±7.52)ml(P =0.029,0.037).Conclusions The ITP has different effects on the two ventricles,and subsequently generates a pressure gradient across the IVS which can alter its shape and position at end-diastole.With the IVS shifting,the preload and filling function of left ventricle gets changed acorrding to the Frank Starling principle.
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Currently, medical ultrasound teaching focuses on the delivering the image infor-mation itself, while its connection with basic medicine and clinical medicine is neglected. Such a teaching method is not good for students to establish a systemic view. To conduct the ultrasound medi-cine education effectively in undergraduate students, we have tried some reforms, including: perform-ing diseases or problem based teaching, integrating basic medicine, ultrasound medicine and clinical medicine throughout the whole teaching process, providing as many practice opportunities as possible for the graduates and integrating the ultrasound imaging with other medical imaging modalities. The practice shows that with the reform, the students have a better understanding of ultrasonic knowledge itself, a better grasp of the whole medical knowledge structure, and also have a preliminary impression on how to diagnose the disease through reasonable application of different treatments. In addition, students have more passion for study.
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Objective To propose an accurate method of noninvasive determination of central venous pressure(CVP ) by locating the central point of right atrium (RA ) using echocardiography .Methods Through the 3D reconstruction ,the accurate positions of RA of 30 patients who had been examined by multislice 3‐dimensional computed tomography for chest imaging were recorded .Based on solid geometric principles ,the central point in RA was located by echocardiography and then compared with CT‐location point .The accuracy and feasibility were assessed by absolute distance (Da) ,vertical distance (Dv) and the whole time of location (T) between the two points .Results Mean Da ,Dv and T of the whole subjects were 07.6cm(95% CI:06.2to08.1cm),01.6cm(95% CI:-00.2to03.4cm),and438.0s(95% CI:400.1to 47 4.0 s) ,respectively .Conclusions The echocardiographic method on the basis of solid geometry proposed in this study could be used to locate the central point in RA accurately and simply .Thus it would be helpful to improve the accuracy of noninvasive determination of central venous pressure .
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Objective To determine the central venous pressure (CVP) noninvasively based on hemodynamics principles using ultrasound location of the collapse point of the internal jugular vein.Methods Forty patients were enrolled in this study.The collapse point of the internal jugular vein was located and marked by a linear transducer,the body mark of right atrium was marked on the right lateral wall of the chest.The noninvasive CVP was calculated according to the vertical distance between those two points.The invasive CVP determination by central venous catheter was also carried out on all the patients.Correlation analysis was used to compare the invasive and noninvasive methods.With invasive determination of CVP as the gold standard,the ROC curve of the noninvasive ultrasound method was sketched to explore the optimal cut-off points.Results The correlation analysis reveal high positive correlation between CVPs determined by ultrasound imaging and central venous catheter (r =0.906,P ＜0.01).By the ROC curve test,fluid column height of 10.75 cm by ultrasound method was determined as the cut-off point,with the sensitivity and specificity of diagnosing elevation of CVP being 88.9％ and 93.5 ％ respectively.The corresponding area under the curve was 0.971.Conclusions Ultrasound imaging could be used to determine CVP noninvasively,which would be helpful in diagnosis of the circulating load of patients.
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Objective To explore the value of superior vena cava (SVC) Doppler spectrum in evaluation of the therapeutic effects of intermittent hypobaric hypoxia (HBHO)-induced pulmonary hypertension (PH) in rats and establish a new method for assessing pulmonary hypertension.Methods Fifty male SD rats were included.Forty of them were developed HBHO-PH and randomly divided into four groups with different manipulations:beraprost treatment group,sildenafil treatment group,placebo group and model group,with 10 rats in each group.The rest of 10 rats served as controls.Cardiac structure,pulmonary peak velocity (PAVmax),tricuspid peak velocity (TVEmax) and SVC Doppler ultrasound were performed in all rats before and after treatment for 2 weeks.Pulmonary arterial pressure was determined by the right heart catheterization.The relationship of the parameters with the pulmonary arterial pressure was analyzed.HE staining was done in lung tissues.Results Right heart catheterization showed that pulmonary artery systolic pressure (PASP) of the treatment groups were lower than that of the model group,the difference was significant(P ＜0.01).Pulmonary artery pressure decreased in varying degrees both after placed in a normal environment and after 2 weeks of treatment.PASP of the beraprost treatment group and the sildenafil treatment group decreased significantly and showed no statistical significant difference with the control group.In contrast,PASP of the placebo group was significant higher than that of control group(P ＜ 0.05).No statistically significant difference was found between the non-placebo treatment groups in PASP.Compared with the control group,the right ventricle/body weight ratio of the model group was statistically significant increased in all other groups(P ＜0.01).Right SVC AR/S ratio was well correlated with PASP (r =0.603,P =0.001).Right SVC AR/S ratio was statistically significant lower in treatment groups compared with the model group (P ＜0.01).All groups except the control group demonstrated various degrees of pulmonary arterial wall thickening.Conclusions The right SVC spectrum of AR/S correlates well with PASP and can be used to evaluate the pharmacological therapeutic effect of rats with HBHO-PH,in particular with moderate to severe PH.
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Objective To investigate the affecting factors of interventricular septum (IVS) swing by study of the mechanical model of the respiration-driven variation of cardiac function using echocardiography.Methods In present study,the equivalent mechanical model of septal swing in previous study was used.By changing the end-diastolic pressure difference between the simulated right and left ventricles and simulated intrapericardial pressure,the subsequent influences on IVS swing using echocardiography were observed.Results Under the rhythmic respiratory intrathoracic pressure change(RIPC)(0--4 mm Hg,1 mm Hg =0.133 kPa),the swing amplitude of simulated IVS increased with decrease of the simulated end-diastolic pressure difference between the simulated right and left ventricles (2.2-17.6 mm).With increasing of the simulated intrapericardial pressure,the simulated right ventricle and left ventricle collapsed in succession,the swing amplitude of simulated IVS also increased to a maximal amplitude of 22.4 mm.Conclusions The affecting factors of IVS swing including the magnitude of RIPC,the end-diastolic pressure difference between the two ventricles and the intrapericardial pressure.
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Objective To investigated the value of intraoperative ultrasonography in guiding the surgical approach,improving the total resection rate of the tumor,and the survival time of patients who underwent resection of cerebral gliomas.Methods One hundred and ninteen patients with cerebral gliomas (pathologically confirmed) comprised the study groups.Patients who underwent intraoperative ultrasoundguided surgery were followed up for 6-60 months.In addition,randomly selected low and high grade cerebral glioma patients (all 30 cases of which were without intraoperative ultrasonography guidance) served as the control groups.Follow up included survival time,and the differences in survival time between the study groups and control groups were statistically analyzed.Results Complete follow-up data were obtained for 101 of 119 cases (84.9％) for a follow-up time of 6 60 months.Total removal of the lesion was achieved in 68 cases (67.3％) and subtotal removal in 33 cases (32.7 ％).Sixty-five cases had partial recurrence (64.4％) and 60 patients died due to tumor recurrence.Survival in patients with low grade gliomas (LGG) was significantly higher than that in patients with high grade gliomas (HGG).Patients with total tumor resection had a longer survival time than patients who had subtotal tumor resection.In the control LGG group,6-month survival was 96.7％,1-year survival was 73.3％,2-year survival was 53.3％,4-year survival was 36.7％ and 5-year survival was 26.7％.In the control HGG group,survival at 6 months,1 year,2 years,4 year and 5 years was 83.3％,36.7％,13.3％,3％,0 respectively.When comparing survival between the control groups and study groups,there was no significant difference at 6 months (P ＞0.05),but survival at 1 year,2 years,4 year and 5 years was different (P ＜0.05).Conclusions Intraoperative ultrasonography-guided resection of cerebral gliomas helps the surgeon to understand the relationship between the lesion and the surrounding structures,helps to protect normal brain tissue and increase the safety of surgery.It is of value in improving the total resection rate of tumors and the patient's survival time.
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Objective To reveal the exact mechanical principle of the respiration-driven variation of cardiac function by observing the effect of respiratory intrathoracic pressure change (RIPC) on the mechanical models using echocardiography.Methods Model 1 was designed to observe the influence of RIPC on systemic and pulmonary venous return systems (SVR and PVR) respectively.Model 2,as an equivalent mechanical model of septal swing,was used to study the influence of RIPC on the motion of the interventricular septum (IVS).Results Model 1 demonstrated that the simulated RIPC had totally different influences on the simulated SVR and PVR.It increased the volume of the simulated right ventricle when the internal pressure was kept constant (8.16 cm H2O),while it had the opposite effect on PVR.Model 2demonstrated that there was a corresponding relationship between RIPC and the position of the simulated IVS which might be called pressure-position relationship.Conclusions The different anatomical arrangement of the two venous return systems leads to a different effect of RIPC on right and left ventricles,and thus generates a pressure gradient across IVS that tends to shift IVS left-and right-wards with respiration.The swing of the IVS changes the short axis diameters of the ventricles,thus their fillings and then their functions reciprocally.
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ObjectiveTo test the reproducibility of wave intensity (WI)analysis derived measurements of pulse wave velocity (PWV),and to compare it with the traditional method-applanation tonometry.MethodsOne hundred and ten outpatient volunteers were enrolled in the study.The R-W1 of right brachial artery and right posterior tibial artery were measured through WI in diagnostic ultrasound equipment (Aloka α10),and were used to calculate the right brachial artery PWV which were also measured by tonometry (VP-1000) simutaneously;thus 30 of these volunteers were randomly selected to repeat the above examinations in the same session.Differences between the two methods were investigated by means of a paired t-test,and their linear correlations were also analyzed.Bland-Altman method was used to analyze the agreement between the two methods and their intraobserver intrasession variabilities.ResultsMean baPWVs determined by WI and tonometry were (13.03 ± 1.93) m/s and ( 12.05 ± 2.02) m/s,respectively (P ＜0.001),and the mean of their difference was (0.98 ± 1.1)m/s giving 95 ％ limits of agreement of ( - 1.18 m/s,3.14 m/s).Values of PWV obtained by the two systems were highly correlated( r =0.85,P＜ 0.001 ),with their intraobserver intrasession variabilities being 8.2％ and 7.0％,respectively.ConclusionsWI provides a new noninvasive and convenient method to measure PWV with good agreement and similar reproducibility to the standard tonometry system.
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Objective To investigate the clinical value of blood vessel diameter tracking and X-strain technology in evaluating the carotid elasticity in patients with diabetes.Methods Thirty-eight patients who were confirmed as diabetes without complications were enrolled in this study as the patient group and thirtyseven healthy volunteers matched with the patient group with sex,ages were typed as controls.The parameters reflecting common carotid elasticity:pulse wave velocity ( PWV),compliance coefficient (CC),stiffness index ( β),endovascular circumferential strain,strain rate,strain time ( EN _ CS,EN _ CS_ T,EN_CSR,EN_CSR_T),adventitial circumferential strain,strain rate,strain time (EP_CS,EP_CS_T,EP_CSR,EP_ CSR_ T),radial strain ( RS),radial strain rate (RSR) and radial strain time (RST) were measured using blood vessel diameter tracking technique and X-strain technique.Significant difference between the two groups and correlations among these variables were evaluated.Results In patient group,PWV and β were significantly higher than those of the control group,while variables like CC,EN_CS,EN_CSR,EP_CS,EP_CSR,RS and RSR were lower with P ＜0.05.All strain time prolonged in patient group ( P ＜0.05).No significant differences were observed in longitudinal strain index.Furthermore,CC was inversely related with PWV( r =- 0.872,P ＜0.001 ),and age,systolic pressure,β were positively related with PWV ( r =0.322,P =0.005; r =0.384,P =0.001; r =0.927,P ＜0.001) in patients group.Conclusions The stiffness and compliance indexes measured by blood vessel diameter tracking technique and the circumferential and radial strain index obtained by X-strain technique can reflect vessel elasticity change of patient with diabetes objectively.
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ObjectiveTo explore the characteristics of the fetal pulmonary venous Doppler spectrum in medium-term and terminal pregnancy and to evaluate its application in the cardiac function assessment and lung maturation.Methods The study group consisted of 86 normal fetuses aged from 23rd to 41st week's gestation.The Doppler echocardiography was used to record the pulmonary venous spectra.The peak diastolic velocity (D),deceleration time of D wave,deceleration of D wave (Ddec),the peak systolic velocity (S),acceleration time of S wave,and acceleration of S wave of the right superior pulmonary vein (Sac.c) were measured.Sacc/Ddec was calculated.The Tei index of the left ventricle was calculated.ResultsThe D and deceleration time of D wave and Ddec increased with gestational age (P ＜ 0.05).S,the acceleration time of S wave and Sacc showed no significant correlation with gestational age.Sacc/Ddec ratio was more likely smaller than 1 with the gestational age less than 28 weeks and larger than 1 with the gestational age longer than 28 weeks ( P ＜0.05).ConclusionsD wave flow velocity,deceleration time of D wave and the Ddec of the right superior pulmonary vein had a good correlation with the global left ventricular function.The Sac/Ddec ratio might be new index for assessing cardiac function and lung maturation.
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Objective To explore the value of transthoracic echocardiographic suprasternal view in the diagnosis of the subtype of the patent ductus arteriosus(PDA).Methods Sixty-five cases with PDA were examined by transthoracic echocardiographic suprasternal view and parasternal great artery short axis view respectively before closure therapy.The diameters of both the aotic and pulmonary side were detected,and subtype diagnoses were made.The results were compared with those from digital subtraction angiography (DSA).Results The demonstrated rates of PDA were 100％ on the parasternal great artery short axis and suprasternal views.Of the 65 cases,12 cases,19 cases and 19 cases were the funnel type of PDA checked on the parasternal great artery short axis view,suprasternal view and DSA respectively.The demonstrated rate of the parasternal great artery short axis view was lower than that of the suprasternal view (x2 =5.14,P ＜0.025 ).The diameter of the aotic side of PDA was (8.31 ± 2.76)mm,(10.87 ± 3.26) mm and (11.15±3.29)mm and the diameter of the pulmonary side of PDA was (5.69± 2.82)mm,(5.75 ± 2.63)mm and (6.09 ± 2.78) mm respectively on the above two views and DSA.Conclusions The diameter of the aotic side of PDA can be accurately detected by using superasternal view,which would be helpful for the diagnosis of PDA subtype.
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Objective To evaluate whether global 2-dimensional strain imaging can offer additional benefit over conventional echocardiography to detect subclinical myocardial damage in patients with chronic kidney disease(CKD). Methods Conventional echocardiography and global 2-dimension strain imaging were performed in 39 patients with CKD [23 men and 16 women,mean age (45.6± 14.6) years] and 29 control subjects. Twenty patients had CKD stage 2 or 3(group 1 ) and nineteen patients had CKD stage 4 or 5(group 2). Left ventricular structure and function were evaluated by conventional echocardiography. Global longitudinal and circumferential strain and strain rate were analyzed. Results There were no differences in ejection fraction and fraction shortening between CKD patients and controls. Compared with controls, CKD groups had significantly decreased value of global longitudinal strain and strain rate. Global longitudinal strain decreased from - (23.8 ± 3.1 ) % in controls to - ( 18. 5 ± 2.4) % in group 1 and to - (15.2 ± 3.2) % in group 2 ( P ＜0. 001 ). Compared with controls, there was no difference in global circumferential strain and strain rate between group 1 and controls, but global circumferential strain and strain rate of group 2 was reduced [ - (17.1± 3. 0) % vs -(21.2±2.8)%, P＜0.05;-(1.0±0.2)% vs -(1.3±0.3)%, P＜0.05]. In correlation analyses, global longitudinal strain was positively related to eGFR( r =0. 376, P ＜0. 001 ) and inversely related to left ventricular mass index( r = - 0. 473, P ＜0.01). Conclusions Global 2-dimensional strain imaging may represent a useful tool for the assessment of subclinical myocardial dysfunction in patients with CKD.
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Objective To study the effects of duration of migration from sea-level to high-altitude on cerebral hemodynamic parameters and their ethnic differences.Methods This randomized comparative study recruited 5 groups of healthy male subjects which were native Hans at sea-level (NHS),Han migrants from sea-level to high-altitude (HMSH,where HMSH-a for residence duration of 4 days,HMSH-b for 1 year,and HMSH-c for 5 years),and native Tibetans at high-altitude (NTH).Color duplex Doppler sonography (CDDS) was used to measure bilateral vertebral and internal carotid arterial diameters,mean flow velocities.The heart rate,arterial blood pressure,and arterial oxygen saturation were also recorded simultaneously,and in combination,hemoglobin was measured to assess total cerebral blood flow (TCBF),total cerebrovascular resistance (TCVR),and total cerebral oxygen supply (TCOS).Results After migration to high-altitude,Hans' TCVR and TCBF maintained the level of NHS after transient changes during early stage (P<0.05),and the TCBF was markedly higher than that of NTH (P<0.05);while the blood pressure and TCOS increased abruptly (P<0.05) at the beginning and kept for a relatively long time at a constant level which were higher than those of NTH all the time (P<0.05).Conclusions Han migrants can acclimate to high-altitude by adaptive change of cerebral blood flow over a short time and maintain a constant adaptability which is always weaker than that of native Tibetans.CDDS can be used for non-invasive measurement of actual cerebral blood flow,and is of good value in the study on high-altitude-related cerebral hemodynamics.
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Objective To investigate the value of intraoperative contrast-enhanced ultrasound(CEUS) in evaluating pathological grades of cerebral gliomas. Methods Intraoperative CEUS was performed in 33 patients of cerebral gliomas of different pathological grades. Real-time blood perfusion and enhance characteristics of these tumors were observed,quantitative parameters from the automatically derived time-intensity curve (TIC) were obtained, and compared with the tumor microvessel density (MVD) by immunostaining with anti-CD34. Results The time to peak was significantly shorter and the MVD was significantly higher in the high grade cerebral gliomas compared with the low grade ones ( P <0. 05). The time to peak was negatively correlated with the MVD by immunostaining (r = -0.79, P < 0. 05). Conclusions Intraoperative CEUS could be used to observe microvascular perfusion in real-time, and could indirectly reflect the information of MVD in cerebral gliomas, which is of help to grade cerebral gliomas and guide surgical resections.
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Objective To evaluate the hemodynamic changes in patients with middle cerebral artery (MCA) stenosis pre- and post-stenting by transcranial color-coded and pulsed-Doppler sonography.Methods Thirty patients with middle cerebral artery stenosis were included.Two-dimensional,color-coded and pulsed-Doppler sonography were used to monitor the morphologic and hemodynamic changes of the MCA before,in the middle of,and after the endovascular stenting operation.All patients were verified by digital substract angiography.Results The hyper-echoic stent grafts and also the size and location of the stent were clearly shown by two-dimensional ultrasonography in 28 patients.The systolic,diastolic and the timeaveraged maximal flow velocities significantly decreased both instantly and 3 - 7 d after the stenting.Specifically,the systolic peak flow velocity of the MCA dramatically decreased immediately after the stenting [(151.43 ± 25.14) cm/s vs (286.13 ± 57.38)cm/s,P ＜0.05],and showed a further decrease after 3 - 7 d [(108.80 ± 9.95) cm/s vs (151.43 ± 25.14) cm/s,P ＜0.05].Conclusions Transcranial color-coded and pulsed-Doppler sonography could be used to evaluate the hemodynamic changes after MCA stenting,and could be considered as the first choice of method for evaluating the therapeutic outcome of stenting.
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ObjectiveTo quantify the underestimation of cardiac blood flow velocities measured by Doppler echocardiography and to explore a method for correction using a new explored dual PW/TDI technique.MethodsThe dual PW/DTI mode was used to simultaneously record the aortic,mitral,tricuspid and pulmonary valvular blood flow velocity and the adjacent valvular annulus velocity in forty healthy volunteers,then the underestimations of the flow velocities were calculated.ResultsThe true blood flow velocity relative to the valvular annulus could be obtained by dual PW/TDI technique.Conventional Doppler echocardiographic measurements significantly underestimated the true velocity ( P ＜ 0.001).The actual aortic blood flow velocity had a significant underestimation of (8.5 ± 1.2) ％,the actual flow velocity of the pulmonary artery had a significant underestimation of (6.6 ± 1.1) ％,the underestimations of E and A wave of mitralvalve's were (13.4 ± 1.7)％ and (16.7± 3.4)％,the underestimations of E and A wave of tricuspid valve' s were ( 18.7 ± 1.9) ％ and (26.0 ± 16.1 ) ％.ConclusionsThe cardiac blood flow velocity measured by Doppler ultrasound has been significantly underestimated and this underestimation can bequantified and corrected using dual PW/DTI technique based on the principle of motion relativity.