Investigation of the effect of exhaust particles on ocular blood flow in highway toll collectors using color Doppler ultrasonography

PURPOSE: To investigate the effect of exhaust particles on orbital blood flow velocity of the ophthalmic artery, central retinal artery, and posterior ciliary artery by color Doppler ultrasonography in highway toll collectors. MATERIAL AND METHODS: Color Doppler imaging was used to measure the peak-systolic and end-diastolic flow velocities and resistivity indices of the ophthalmic artery, central retinal artery, and posterior ciliary artery in 20 toll collectors and 20 controls. RESULTS: Both the peak-systolic and the end-diastolic flow velocities were decreased in the ophthalmic artery, central retinal artery, and posterior ciliary artery, and the resistivity index was increased in the central retinal artery in toll collectors when compared with control groups. Results were considered statistically significant if P<0.05. CONCLUSION: It was determined that the effect of exhaust particles reduced ocular blood flow velocity in toll collectors as measured by color duplex Doppler ultrasonography.     

Doppler ultrasonography findings in ocular Behçet's disease

The aim of this prospective study was to determine and compare the orbital Doppler ultrasonography parameters of patients with Behçet's disease (with or without ocular involvement) with those of healthy subjects. We evaluated ophthalmic artery (OA), central retinal artery, posterior ciliary artery (PCA), central retinal vein, and superior ophthalmic vein (SOV) flow velocities and resistance indices (RIs). Detection of the decreased flow velocities in the OA and SOV and the increased RI in the OA and PCA might allow the identification of active period of patients with Behçet's disease.     

Transcranial Doppler ultrasonography in neurologically asymptomatic children and young adults with sickle cell disease

The purpose of the study was to evaluate transcranial Doppler ultrasonography for identifying cerebrovascular disease in neurologically asymptomatic children and young adults with sickle cell disease. A total of 47 consecutive patients with sickle cell disease (28 females, 19 males; age range 8 months to 29 years, mean age 9 years 6 months) were evaluated by transcranial color and duplex Doppler ultrasonography via transtemporal and occipital (2-MHz probe) as well as by transocular (5-MHz probe) approach. Eleven vessels (middle, posterior, anterior cerebral artery, vertebral artery, ophthalmic artery on each side and basilar artery) were analyzed in each patient. Following nine transcranial Doppler findings predictive for cerebrovascular disease, patients with one or more of those abnormal sonographic findings underwent MR imaging and MR angiography. In 8 patients with abnormal transcranial Doppler the MR angiography was normal. Thirty-one patients demonstrated normal results. In 15 of 16 patients with one or more abnormal Doppler findings (34% of all studied patients) MR imaging and MR angiography were performed. The MR angiography disclosed cerebrovascular stenosis in 7 patients (15% of all patients, 44% of those with pathological transcranial Doppler findings). In one of those patients MR imaging revealed silent peripheral ischemic infarction as well. Our findings indicate the usefulness of transcranial Doppler ultrasonography to reveal occult cerebrovascular lesions in neurologically asymptomatic patients with sickle cell disease. It should regularly be performed in all sickle cell patients in order to detect patients at risk for later stroke. Patients with homozygous disease and a high frequency of preceding sickle cell crises should be followed most closely. Electronic Publication     

Efficiency of placental three dimentional power Doppler ultrasonography for predicting preeclampsia in early pregnancy

Purpose

to evaluate the role of three dimentional power doppler ultrasonography (3D PDUS) of the uteroplacental circulation in early pregnancy as a screening tool for prediction of preeclampsia.

糖尿病眼底动脉血流动力学的彩色多普勒超声研究

目的:探讨糖尿病眼底血流动力学的变化。方法:彩色多普勒超声检测糖尿病患者67例和正常对照者40例的视网膜中央动脉(central retinal artery,CRA)、睫状后动脉(posterior ciliary artery,PCA)的收缩期血流峰值速度(PSV)、舒张末期血流速度(EDV)、阻力指数(RI),分析糖尿病视网膜病变(diabetic retinopathy DR)和糖尿病不伴视网膜病变(non-diabet-ic retinopathy,NDR)时其血流动力学的改变以及正常人不同年龄组血流参数的变化规律。结果:正常人不同年龄组间的PSV差异有显著性意义(P<0.05);不同年龄组间EDV、RI差异无显著性意义(P>0.05)。与对照组相比较,糖尿病患者PCA、CRA的血流速度减低,阻力指数增高,差异有显著性意义;且在无视网膜病变时不仅CRA而且PCA也存在血流动力学的异常。结论:彩色多普勒超声对糖尿病眼底动脉血流动力学变化的显示具有较高临床价值。     

Determination of the effect of a single hemodialysis session on retrobulbar blood hemodynamics by color Doppler ultrasonography

Background: Retrobulbar hemodynamic alterations can occur during hemodialysis sessions, and patients with chronic renal failure may experience visual problems.

Purpose: To evaluate the effect of single-session hemodialysis on retrobulbar vessel hemodynamics by color Doppler ultrasonography.

Material and Methods: Thirty-five patients were included in the study. Retrobulbar blood flows were examined before and after dialysis sessions. Doppler spectral patterns of retrobulbar blood flow were evaluated. The t test for paired samples and the Wilcoxon matched-pairs signed-rank test were used for comparing the flow values before and after dialysis.

Results: Systolic and diastolic blood flow velocities of the ophthalmic artery, central retinal artery, central retinal vein, nasal posterior ciliary artery, and temporal posterior ciliary artery were found to be decreased bilaterally after hemodialysis sessions. No significant change was observed in resistivity index values after hemodialysis sessions.

Conclusion: Our findings reveal that retrobulbar circulation was disturbed after a single hemodialysis session.     

低温条件下兔肾脏血流动力学超声检测

目的:探讨低温条件下兔三级肾动脉血流动力学变化规律.方法:建立兔低温模型,选取20只兔,平均分为5组,分别置于室温,-10℃和- 15℃中,分别于4h和8h时进行肾脏二维超声及彩色多普勒检查(CDFI).二维超声测量肾脏大小,记录其长、宽、厚径;多普勒流速曲线分析肾门部主肾动脉(MRA)、肾窦部段动脉(SRA)中部和肾锥体两侧缘的叶间动脉(IRA)的血流动力学指标:收缩期峰值血流速度(PSV/Vs),舒张末期最低血流速度(EDV/VD),阻力指数(RI).结果:低温条件下肾脏的各径线测值均无改变;血流参数收缩期峰值血流速度,舒张期最低血流速度和阻力指数在各级肾动脉表现出不同的特点.结论:超声检查可以反映低温条件下兔三级肾动脉的血流动力学改变,可为临床研究低温所引起的肾损害提供信息.     

超声对颈动脉内膜剥除前、后颅内外血流动力学变化的评价

目的:探讨彩色多普勒血流成像(CDFI)和经颅彩色多普勒血流成像(TCCDFI)评价颈动脉内膜剥除术(CEA)治疗前、后患者颅内外动脉血流动力学的变化。方法:用CDFI和TCCDFI分别对23例颅外段颈内动脉(EICA)狭窄患者CEA治疗前、后狭窄局部管径、收缩期峰值流速(PSV)及同侧大脑中动脉(MCA)、眼动脉(OA)CEA治疗前、后PSV、搏动指数(PI)和颅内侧支循环的建立情况进行分析。结果:EICA狭窄患者CEA术后原狭窄处内径、PVS及患侧MCA、OA的PSV、PI恢复正常,侧支循环关闭。结论:CDFI与TCCDFI结合可评价颈动脉狭窄患者行CEA治疗前、后颅内外动脉的血流动力学变化,对判断CEA的疗效具有重要的临床价值。     

彩色多普勒超声对缺血性视乳头病变早期血流动力学的研究

目的:探讨缺血性视乳头病变早期患者眼血流动力学变化。材料和方法:应用彩色多普勒血流成像(CDFI)技术检测40例患者与36例健康志愿者眼动脉、视网膜中央动脉、睫状后动脉收缩峰值速度(PSV)、舒张末期流速(EDV)、阻力指数(RI)及视网膜中央静脉最大流速(Vmax)。结果:与正常组比较,患者组眼动脉PSV无显著差异(P>0．05), EDV减低、RI增高(P<0．05);视网膜中央动脉PSV、EDV减低,RI增加(P<0．05);睫状后动脉PSV、EDV明显减低, RI明显增加(P<0．01);视网膜中央静脉Vmax减低(P<0．05)。结论:CDFI可评估缺血性视乳头病变早期眼血流动力学变化,为临床提供诊断信息。     

Cerebral hemodynamics in asymptomatic patients with internal carotid artery occlusion: a dynamic susceptibility contrast MR and transcranial Doppler study.

BACKGROUND AND PURPOSE: Perfusion imaging with dynamic susceptibility contrast MR imaging (DSC-MRI) has been used to evaluate hemodynamic status in patients with symptomatic occlusive cerebrovascular disease. The aim of the present study was to determine the hemodynamic changes occurring in asymptomatic patients with unilateral internal carotid artery (ICA) occlusion by use of DSC-MRI with transcranial Doppler (TCD) measurement of the breath-holding index (BHI). METHODS: Nine patients with asymptomatic unilateral ICA occlusion underwent DSC-MRI and TCD examination. One patient was excluded from final analysis because of severe movement artifacts. On a separate workstation, regional cerebral blood volume (rCBV), regional cerebral blood flow (rCBF), and regional mean time to peak (rMTT) were calculated on the basis of signal decay rate during the passage of gadolinium bolus through the sampled volume in the territory of the middle cerebral artery. TCD-BHI was calculated in all patients. Six healthy subjects underwent the same MR protocol as the patients. RESULTS: Compared with control subjects, patients with unilateral ICA occlusions had hemodynamic changes in the ipsilateral hemisphere: rCBF was significantly lower than in controls (P <.01), and r MTT was significantly increased in both white (WM) and gray matter (GM) in the affected side (WM: P <.01; GM: P <.05). No statistically significant difference in rCBV was found in the group of patients (occluded versus contralateral, P <.1) or between the patient and control groups (occluded side versus controls, P <.1). The correlation of rCBV and BHI showed a strong relation of the two variables, showing a decrease of the latter when the former increased. CONCLUSION: DSC-MRI is a valuable tool for measuring hemodynamic changes in the presence of carotid disease with hemodynamic impairment. In our opinion, hemodynamic changes and efficiency of collateral pathways can be evaluated in occlusive carotid disease by using paired measurement of BHI and DSC-MRI. In the patient group, MR-determined rCBV and TCD-determined BHI showed a significant inverse correlation, suggesting similar significance of the two indices.     

肝外梗阻性黄疸的血流动力学研究

目的探讨肝外梗阻性黄疸对肝脏血流动力学的影响.材料和方法应用彩色多普勒血流显像仪测定23例肝外梗阻性黄疸患者的肝固有动脉和肝左静脉血流,并与23例单纯胆囊结石患者和23例正常人对比.结果肝外梗阻性黄疸患者肝固有动脉内径、血流速度、血流量显著高于正常人和单纯胆囊结石患者;而正常人和单纯胆囊结石患者之间无差别.肝左静脉血流测值在各组之间均无显著差别.结论梗阻性黄疸时肝固有动脉血流量明显增多;肝左静脉病变较门静脉轻.     

Value of color Doppler ultrasonography in the evaluation of orbital vascular flow in end-stage renal disease patients undergoing hemodialysis

Purpose: To evaluate choroidal and retinal vascular flow dynamics by means of color Doppler ultrasonography in patients with end-stage renal disease undergoing hemodialysis and to compare these findings with healthy controls. Material and Methods: Color Doppler ultrasonography and spectral analysis of nasal and temporal posterior ciliary and central retinal artery flow of both eyes were performed in 20 patients (40 eyes) and 22 controls (44 eyes) to assess peak systolic flow velocity, end-diastolic flow velocity, and resistive indices (RI). Patients with hypertension, diabetes mellitus, and any cardiac pathology were not included in the study. A general ophthalmologic examination was performed in all patients and controls. Results: The average peak-systolic and end-diastolic blood flow velocities of nasal (12.88±4.91/6.88±3.26) and temporal (15.22±9.59/6.41±3.97) posterior ciliary artery and central retinal artery (14.94±8.38/6.7±4.13) in patients were significantly higher than the corresponding values of the controls. The RI values of nasal (0.52±0.10) and temporal (0.58±0.12) posterior ciliary artery and central retinal artery (0.55±0.11) in patients with end-stage renal disease undergoing hemodialysis were significantly lower than in the controls. Conclusion: Choroidal and retinal blood flow velocities are higher and RI values for all three vessels lower in patients with end-stage renal disease undergoing hemodialysis compared to healthy controls. These alterations may be related to either increased choroidal blood flow or vasoconstriction of the proximal vessels.     

Doppler and gray-scale ultrasound evaluation of morphological and hemodynamic changes in liver vascualture in alcoholic patients

OBJECTIVE: The aim of this study is to search sonographically for morphological and hemodynamic changes in hepatic and splanchnic vasculature of alcoholic patients having no signs of hepatic damage, and compare these with normal healthy subjects. METHODS: Thirty alcohol-dependent patients and 30 control subjects with no alcohol problem or hepatic impairment were included in the study. All patients were evaluated by gray-scale and spectral Doppler ultrasound. The diameter of the portal vein, portal venous velocity, peak systolic and end diastolic velocities of hepatic and superior mesenteric arteries were assessed. RI, PI and systolic/diastolic velocity ratios were also calculated. RESULTS: Portal vein cross-sectional area was greater in alcoholic patients compared to control group (P = 0.0012). Portal vein velocity, hepatic artery peak systolic and end diastolic velocity, superior mesenteric artery peak systolic and end diastolic velocity were significantly greater in alcoholic patients than in control group (P < or = 0.001). No statistically significant difference was detected between other parameters evaluated. CONCLUSION: In alcohol-dependent patients, some hemodynamic and morphologic changes occur in hepatic and splanchnic circulation, even before the signs of hepatic damage develop. These changes can be detected by means of Doppler and gray-scale sonogrsphy.     

战斗机飞行员脑血流动力学的研究

目的 探讨战斗机飞行员脑血流动力学的特点.方法 试验对象分为3组：战斗机飞行员组（40名）、运输机飞行员组（30名）和健康对照组（30名）,分别用2 MHz多普勒探头检测颅内各动脉的血流速度及搏动指数.结果 战斗机飞行员组与其他两组比较,颅内动脉各期血流速度呈对称性增快,差异均有显著性意义（P＜0.01）,以大脑中动脉、大脑后动脉、椎动脉、基底动脉和眼动脉血流速度增快明显.搏动指数虽有升高,但无统计学意义.运输机飞行员组与健康对照组相比,各期血流速度差异不显著.结论 战斗机飞行员颅脑动脉高血流流速是一种代偿性生理变化,在飞行鉴定时应引起重视.     

Contrast-enhanced ultrasound Doppler examination of the retrobulbar arteries

PURPOSE: To evaluate the diagnostic usefulness of an ultrasound contrast agent in examination of the retrobulbar arteries. MATERIAL AND METHODS: Ten healthy volunteers received a galactose-based echo-contrast medium (Levovist) by i.v. infusion. The ophthalmic, central retinal, the nasal and the temporal posterior ciliary arteries and the short ciliary arteries were studied in 19 eyes by color and spectral Doppler ultrasonography before and after contrast administration. Peak systolic and end diastolic velocities and spectral Doppler indices (pulsatility and resistive) were assessed. The quality of the spectral and color Doppler imaging of the arteries were visually graded on a 5-point scale. RESULTS: There were significant differences in pre- and post-contrast peak systolic velocities in the ophthalmic arteries (p<0.05), but not in the other retrobulbar arteries, or in any of the spectral Doppler indices. After contrast administration the mean spectral Doppler score for vessels poorly visualized before contrast increased from 2.2 (+/-0.4) to 3.1 (+/-0.9). The number of short ciliary arteries with sufficient spectral Doppler quality increased from 7 prior to contrast to 14 following contrast. Prior to the infusion of Levovist, 62 (73%) out of 85 retrobulbar arteries could be evaluated with a sufficient spectral Doppler quality. Following the administration of contrast 66 (78%) arteries had sufficient spectral Doppler quality. However, by combining the results of the pre- and post-contrast examinations, sufficient spectral Doppler quality was obtained in 77 (91%) of the 85 retrobulbar arteries. CONCLUSION: Contrast enhancement increased the number of detectable retrobulbar vessels. However, in the case of good quality pre-contrast imaging of the retrobulbar vessels, the use of Levovist did not add any substantial diagnostic information. The optimal spectral Doppler results were obtained when both pre- and post-contrast examinations were performed.     

Hemodynamic response changes in cerebrovascular disease: implications for functional MR imaging

BACKGROUND AND PURPOSE: Patients with cerebrovascular occlusive disease may develop compensatory changes in local cerebral vasculature with a resultant loss of vascular reactivity. These alterations can affect the blood oxygen level-dependent (BOLD) signal that is the basis for functional MR imaging. We investigated the BOLD signal in patients with unilateral cerebrovascular disease to ascertain the clinical utility of functional MR imaging in these patients. METHODS: Five healthy volunteers and three patients with cerebro-occlusive disease were imaged with both a block and an event-related design of a visually cued bilateral motor task. Activation maps were calculated, and individual hemodynamic response curves were generated for left and right primary motor cortices. Vascular reserve was determined for the relevant vascular territory by using transcranial Doppler ultrasonography (US). RESULTS: In the event-related data, the amplitude of the BOLD response was significantly decreased in the motor cortex ipsilateral to the stenosis and showed significant delays in the timing of the hemodynamic response. In contrast, the longer duration stimulus and longer TR of the block design showed significant decreases in the BOLD amplitude but no significant interhemispheric temporal differences. Corroborating the hemodynamic status, transcranial Doppler US analysis showed diminished vascular reserve ipsilateral to the lesion. CONCLUSION: Differences in the results between the event-related and block paradigms reflect the sensitivity to alterations in autoregulation or vascular compliance. These changes in the vasculature directly affect the BOLD contrast underlying functional MR imaging. Thus, while this technique remains a useful clinical tool, caution is warranted when studying patients with cerebrovascular disease.     

Change in brain size during and after pregnancy: study in healthy women and women with preeclampsia

BACKGROUND AND PURPOSE: Qualitative decreases in maternal brain size have been observed late in pregnancy. The aim of this study was to quantitatively evaluate changes to the maternal brain during and after healthy pregnancy and to compare these changes with those observed in cases of preeclampsia. METHODS: Three-dimensional T1-weighted MR volume images were obtained in nine healthy participants before and after delivery. Additional images were obtained in some of these participants before pregnancy, during pregnancy, and within 52 weeks after delivery. Five women with preeclampsia were examined before delivery and 6 weeks after delivery. Three of these patients were examined within 52 weeks after delivery. Images were registered, and both brain and ventricular volumes were calculated by using a semiautomated computer program. RESULTS: Both the healthy and preeclamptic groups had a reduction in brain size during pregnancy that was maximal at term and that reversed by 6 months after delivery. The ventricular size showed a corresponding increase in size during pregnancy and a decrease in size after delivery. In the preeclamptic patients, brain size was significantly smaller (P =.05) than in healthy participants, both before and after delivery. CONCLUSION: The brain decreases in size during pregnancy and increases in size after delivery. The changes follow a consistent time course in each woman. The mechanism and physiologic importance of these findings are speculative at the present time.     

Renal blood flow changes induced with endothelin-1 and fenoldopam mesylate at quantitative Doppler US: initial results in a canine study

PURPOSE: To evaluate quantitative Doppler ultrasonography (US) for assessing renal blood flow changes induced with endothelin-1 (ET-1) and fenoldopam mesylate in conscious dogs. MATERIALS AND METHODS: A blood flow probe was surgically implanted around the renal artery in eight adult dogs. Color and power Doppler US images were acquired in conscious restrained dogs during intravenous infusion of ET-1 and fenoldopam mesylate. Simultaneous with imaging, blood flow through the renal artery was measured with the implanted probe. The color level of the images within the region representing the kidney was analyzed to derive flow indices. These indices were compared with direct-flow measurements. RESULTS: The flow indices, color-weighted flow area (CWFA), and percentage of area of color, derived from color and power Doppler US images, correlated linearly with direct flow. The mean color level of color and power Doppler US images correlated weakly with direct flow. Pre- versus postinfusion CWFA decreased with all ET-1 infusions (P < or =.032). Infusion of fenoldopam mesylate increased CWFA in all cases (P < or =.032). CONCLUSION: Quantitative Doppler US enabled successful measurement of the flow changes induced with ET-1 and fenoldopam mesylate. Quantitative Doppler US is potentially useful as a noninvasive surrogate endpoint in evaluating the action of various therapeutic agents.     

Doppler ultrasonography in predicting relapse of hyperthyroidism in Graves' disease

Purpose:
To determine whether Doppler ultrasonography could be useful in the prediction of relapse of hyperthyroidism in patients with Graves' disease.
Material and Methods:
Forty patients with Graves' disease confirmed by laboratory tests were examined for a number of blood flow parameters in the inferior thyroid artery before and after they were subjected to proper antithyroid drug treatment. Data were retrospectively reviewed and compared with findings for a control group of 16 age-matched subjects.
Results:
Significantly increased blood flow parameters were observed both in patients with active hyperthyroidism before treatment and in euthyroid patients who presented a relapse shortly after withdrawal of proper antithyroid drug treatment versus normal controls. Conversely, no significant differences were observed between patients who remained in stable remission and normal controls.
Conclusion:
Our results support the concept that Doppler ultrasonography evaluation of patients with Graves' disease may contribute to the detection of a relapsing course of hyperthyroidism.     

Color Doppler evaluation of the ocular arterial flow changes in chronic obstructive pulmonary disease

PURPOSE: To evaluate the hemodynamic changes in the extraocular orbital vessels of the patients with chronic obstructive pulmonary disease (COPD), using color Doppler ultrasonography (CDU) technique, and to compare the results with those of healthy control subjects. METHODS: Forty-five patients with COPD and 17 healthy control subjects were included in this study. Patients with COPD were classified according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD). Fifteen patients of stage I COPD (mild airflow limitation), stage II COPD (worsening airflow limitation) or stage III COPD (severe airflow limitation) were enrolled into Group I, II and III, respectively. End tidal carbon dioxide (EtCO(2)), peripheral oxygen saturation (SpO(2)), pulse rate (PR) and respiratory rate (RR) were measured by using capnograph/pulse oximeter in all patients. Measurements were performed in only one randomly chosen eye of each participant. The peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistance index (RI) were measured in the ophthalmic artery (OA), central retinal artery (CRA), lateral short posterior ciliary artery (LPCA) and medial short posterior ciliary artery (MPCA), using CDU technique. RESULTS: The PSV measurements of the OA were significantly higher in Groups II and III compared to control group (p < 0.01, p < 0.001, respectively). The RI values from OA and CRA were significantly higher in Group II and III than the control group (p < 0.05). The RI values of LPCA and MPCA were also significantly higher in Group II than the control subjects (p < 0.05). When RI values were compared, mean values of LPCA and MPCA were significantly lower in Group III than in Group II (p < 0.05). There were no significant differences between Group I and control patients about PSVs, EDVs and RI values of all arteries Statistically significant correlations were found for the EtCO(2) with PSV (r = 0.53, p < 0.01) and EDV (r = 0.51, p < 0.01) of the OA. Statistically significant correlations were also found for the SpO2 with RI (r = -0.34, p < 0.05) in the OA. CONCLUSION: We concluded that COPD is associated with impaired retrobulbar hemodynamics, especially in the ophthalmic artery. Moreover, central retinal and posterior ciliary arteries with increased resistance are also found to be affected when compared with healthy control eyes.