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Mean Blood Flow Velocities (mean + blood_flow_velocity)
Selected AbstractsCerebral Vasospasm in Childhood Migraine During the Intermigrainous PeriodJOURNAL OF NEUROIMAGING, Issue 2 2004Lauren E. Boasso ABSTRACT Background and Purpose. The aims of this study were to evaluate the changes in intracranial hemodynamics and assess the presence of vasospasm in children with migraine during the intermigrainous period. Methods. Transcranial Doppler (TCD) sonography findings, clinical examinations, and the vasospastic index of Lindegaard were analyzed for children who fulfilled the criteria for childhood migraine. The significance of the presence of vasospasm and abnormal hemodynamics were statistically analyzed using the normal approximation to the binomial test method. TCD sonography was performed using the standard published techniques for children. Results. Sixty-two patients between the ages of 5 and 17 years who had undergone at least one TCD sonographic examination were selected for this study. A total of 113 TCD sonographic examinations were performed on the patients. Elevated mean blood flow velocities were found in 23 of 62 patients (37%) (P< .001). Early vasospasm was found in 4 of 62 patients (6.5%) (P< .001). Bruits were noted in 35 of 62 patients (56%). Conclusions. This study raises the possibility of cerebral vasospasm in the intermigrainous period in childhood migraine. Further studies are needed to elaborate on the pathophysiology of cerebrovascular behavior during this period. These findings may have a significant impact on the current clinical treatment of childhood migraine. [source] Cardiocirculatory effects of patent ductus arteriosus in extremely low-birth-weight infants with respiratory distress syndromePEDIATRICS INTERNATIONAL, Issue 3 2003Senji Shimada Abstract Background:,Cardiocirculatory effects of hemodynamically significant patent ductus arteriosus (hsPDA) have not been systematically studied in extremely low-birth-weight (ELBW) infants with respiratory distress syndrome (RDS). The objective of the present study was to evaluate the effects of hsPDA on the left ventricular output (LVO) and organ blood flows in ELBW infants with RDS. Methods:,Extremely low-birth-weight infants (birth-weight <1000 g) treated with surfactant for RDS were studied by serial Doppler flow examinations. Doppler flow variables in 19 infants in whom hsPDA developed (hsPDA group) were compared with those in 19 infants without hsPDA matched for gestational age, birth-weight, and postnatal age (non-hsPDA group). All infants in the hsPDA group had pharmacologic closure of ductus arteriosus when hsPDA developed. Results:,Before pharmacological closure of PDA, the hsPDA group had significantly higher LVO, lower blood flow volume of the abdominal aorta, and lower mean blood flow velocities in the celiac artery, superior mesenteric artery, and renal artery than the non-hsPDA group. These alterations in the hsPDA group reverted to the levels in the non-hsPDA group after the closure of PDA and had no deleterious effects on the cardiorespiratory status. No significant differences between the groups were found in mean blood flow velocities of the anterior cerebral artery throughout the study period. Conclusion:,These results indicate that although LVO is increased, the splanchnic and renal blood flows are decreased when hsPDA develops in ELBW infants with RDS. The effects of these alterations of LVO and organ blood flows on the cardiorespiratory course seem to be minor when early pharmacologic closure of PDA is done. [source] Ultrasound assessment of short-term ocular vascular effects of intravitreal injection of bevacizumab (Avastin®) in neovascular age-related macular degenerationACTA OPHTHALMOLOGICA, Issue 6 2010Philippe Bonnin Acta Ophthalmol. 2010: 88: 641,645 Abstract. Purpose:, Angiogenic inhibitors, alone or combined with other therapies, are believed to represent a promising treatment for neovascularization in age-related macular degeneration (wet AMD). They can maintain or improve visual acuity (VA), at least for the first 2 years. However, evolution to retinal atrophy cannot be ruled out and it may be useful to assess the effects of antiangiogenic therapy on retinal and choroidal circulation. Methods:, We carried out a pilot study in 15 patients with wet AMD. Time-averaged mean blood flow velocities (BFVs) in the central retinal, temporal posterior ciliary and ophthalmic arteries (CRA, TPCA and OA) were measured by ultrasound imaging before and 4 weeks after a single intravitreal injection of 1.25 mg bevacizumab in 0.05 ml. Patients underwent two ophthalmic examinations, before and 4 weeks after injection, including VA measurement and optical coherence tomography (OCT3) examination. Results:, In treated eyes, bevacizumab injection was followed by a significant improvement in VA (from 20/125 to 20/80; p = 0.0214), and a decrease in mean central macular thickness (from 392 ± 96 ,m to 271 ± 50 ,m; p = 0.0038). Mean BFV decreased by 10% in the CRA (p = 0.0226), 20% in the TPCA (p = 0.0026) and 20% in the OA (p = 0.0003). No effect was observed in fellow eyes. Conclusions:, Intravitreal bevacizumab acutely improved VA and reduced central macular thickness in wet AMD. Ultrasound imaging revealed that BFVs decreased in all retrobulbar arteries, suggesting that after local diffusion, bevacizumab exerts a short-term regional effect. Bevacizumab might therefore induce hypoperfusion of the whole eye, which may correspond to a vascular side-effect. [source] Ophthalmic artery blood flow velocity changes in diabetic patients as a manifestation of macroangiopathyACTA OPHTHALMOLOGICA, Issue 2 2000Masanori Ino-ue ABSTRACT. Purpose: The hemodynamic characteristics of ophthalmic artery (OA) blood flow velocity in diabetic patients with ocular involvement were evaluated. Methods: Changes in OA blood flow of eyes with background diabetic retinopathy (BDR), proliferative retinopathy (PDR) and ocular ischemic syndrome (OIS) were ananalyzed by Color Doppler imaging. Results: Patients with BDR and PDR had significantly lower diastolic and mean blood flow velocities and higher pulsatility indices compared to controls. Diabetic patients with OIS had significantly lower systolic, diastolic and mean anterograde OA blood flow velocities than the controls. Pulsatility indices were higher in anterograde OA blood flow measurements compared to controls. Systolic blood flow velocities in rubeotic eyes with OIS were significantly lower than in rubeotic eyes with PDR. Conclusion: OA blood flow measurements by color doppler imaging may detect macroangiopathies in diabetic patients as manifested by carotid atheromas and arterio- and arterosclerosis of the OA and its branches. [source] Assessment of renal function with color Doppler ultrasound in autosomal dominant polycystic kidney diseaseINTERNATIONAL JOURNAL OF UROLOGY, Issue 3 2001Akira Kondo Abstract Background: Measurement of renal blood flow by color Doppler ultrasound is useful for assessment of renal function in a variety of renal disorders. In autosomal dominant polycystic kidney disease (ADPKD), however, it might be difficult to visualize interlobar arteries because of deformity of renal structure. To evaluate the usefulness of color Doppler in ADPKD, parameters determined by blood flow examination were compared with the results of ordinal renal function tests. Methods: Twenty-one patients with ADPKD were examined by color Doppler ultrasound measurement. In each patient, 10 interlobar arteries in both kidneys were investigated. Minimum blood flow velocity (Vmin), maximum blood flow velocity (Vmax), mean blood flow velocity (Vmean), acceleration, resistive index and pulsatility index were measured in relation to the results of creatinine clearance, serum creatinine, blood urea nitrogen and 15 and 120 min values of the phenolsulfonphthalein test. Results: In all patients, interlobar arteries were able to be visualized and blood-flow profile was measured. Although variations of Vmin, Vmax, Vmean and acceleration were relatively large, the resistive index and pulsatility index varied little in each kidney. Mean values of Vmin (P < 0.005), Vmean (P < 0.05), resistive index (P < 0.005) and pulsatility index (P < 0.005) were well correlated to creatinine clearance with statistical significance. Conclusions: In ADPKD, color Doppler ultrasound measurement is a useful method for assessment of renal function and could be used for monitoring the dynamic state of renal blood flow as a non-invasive technique. [source] Assessment of renal circulation in small for gestational age and appropriate for gestational age term newborns: A prospective studyJOURNAL OF CLINICAL ULTRASOUND, Issue 4 2008Hana Kolarovszka Abstract Purpose To compare selected parameters of renal circulation between small for gestational age (SGA) and appropriate for gestational age (AGA) newborns. Methods Fifty-two SGA and 100 AGA term newborns were examined. The size of the kidneys were measured, and renal blood flow in the central and intraparenchymal renal arteries were assessed via Doppler sonography. Peak systolic velocity (PSV), end diastolic velocity (EDV), mean blood flow velocity (V mean), resistance index (RI), and pulsatility index (PI) were determined and compared between the groups. Results No statistically significant differences in the velocity parameters were found between SGA and AGA infants in central renal arteries. Slightly higher RIs and PIs were seen in AGA newborns (RI, 0.76 ± 0.13 versus 0.78 ± 0.06 [p < 0.05]; PI, 1.65 ± 0.54 versus 1.84 ± 0.46 [p < 0.05]). There were statistically significant differences between the groups in all measured parameters in intraparenchymal arteries (RI, 0.57 ± 0.11 versus 0.63 ± 0.05 [p < 0.001]; PI, 0.89 ± 0.26 versus 1.09 ± 0.16 [p < 0.001]) except PSV (7.11 ± 1.55 versus 7.14 ± 0.81 cm/s [p > 0.05]). Conclusion Based on our findings, we suggest that renal circulation is not negatively influenced by intrauterine growth restriction in SGA neonates compared with AGA newborns. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008 [source] Accuracy of transcranial Doppler sonography for predicting cerebral infarction in aneurysmal subarachnoid hemorrhageJOURNAL OF CLINICAL ULTRASOUND, Issue 8 2006Ji-Yong Lee MD Abstract Purpose. To evaluate the accuracy of transcranial Doppler (TCD) sonography using different criteria for predicting cerebral infarction due to symptomatic vasospasm. Methods. We retrospectively evaluated the clinical and radiologic data of consecutive patients admitted with acute aneurysmal subarachnoid hemorrhage (SAH) in the anterior cerebral circulation between January 2001 and June 2002. TCD sonographic examinations were performed on alternate days up to 20 days after admission. Cerebral infarction was defined on CT as a new hypodensity in the vascular distribution with corresponding clinical symptoms. Vasospasm was diagnosed as mild or severe when TCD sonography revealed a mean blood flow velocity (MBFV) greater than 120 and 180 cm/s in the middle or anterior cerebral artery and in the intracranial part of the internal carotid artery, respectively. Results. A total of 93 patients with aneurysmal SAH in the anterior cerebral circulation were included. Vasospasm was demonstrated by TCD sonography in 60 patients (64.5%) and was shown via multivariable logistic regression analysis to be predictive of cerebral infarction (OR 3.11, 95% CI 1.46,6.59), with an 82.6% and 69.6% sensitivity, a 41.4% and 77.1% specificity, a 31.7% and 50.0% positive predictive value, and an 87.9% and 88.5% negative predictive value when the MBFV was greater than 120 and 180 cm/s, respectively. Conclusions. Vasospasm on TCD was found to be predictive of symptomatic cerebral infarction on CT, but its positive predictive value remained low despite the adoption of restrictive TCD criteria for vasospasm. © 2006 Wiley Periodicals, Inc. J Clin Ultrasound 34:380,384, 2006 [source] | ||||||||||