Background and Purpose: Transcranial Doppler blood flow velocities are inversely related to age and hematocrit, but the relative importance of age, oxygenation, and hemorheological factors has not previously been examined. We evaluated the relative contributions of these factors to middle cerebral artery blood flow velocity in adults with chronic renal failure, a population subject to significa...

BACKGROUND AND PURPOSE The effects of hemodialysis on the cerebral circulation of humans and the correlation between changes in blood flow velocity in the basal cerebral arteries and those of several physiological variables influenced by hemodialysis have been inadequately studied. METHODS Blood flow velocities were obtained from the middle cerebral artery and the basilar artery by transcrani...

We evaluated the efficacy of transcranial Doppler ultrasonography in 23 patients suffering from acute middle cerebral artery occlusion. The diagnosis of occlusion was most suggestive when all basal arteries except the affected middle cerebral artery were detectable. Enhanced blood flow velocity in the anterior cerebral artery due to leptomeningeal collateralization was used as a corroborating c...

We assessed the potential of 2-MHz pulsed-wave transorbital Doppler ultrasonography to delineate the role of the ophthalmic artery as a source of collateral cerebral blood supply by comparing oculopneumoplethysmography, transorbital Doppler ultrasonography, periorbital continuous-wave Doppler ultrasonography, and transcranial Doppler ultrasonography in 25 patients with unilateral internal carot...

OBJECTIVE The purpose of this study was to evaluate with Color Doppler the influence of type of delivery, sex, postnatal age and time post feeding on full term healthy newborns cerebral blood flow. METHOD 50 newborns were studied. The Doppler parameters, peak-systolic velocity, end-diastolic velocity, mean velocity, pulsatility index and resistance index, were measured in the anterior cerebra...

Introduction: Nitric oxide seems to play a dual role in ischemia/reperfusion injury. Few studies have investigated whether it exacerbates or improves brain edema. In the present study, we inhibited the activity of nitric oxide synthase by L-NAME and evaluated the cerebral infarct volume, tissue swelling and brain edema, alongside the measurement of blood flow of the ischemic region. Methods...

OBJECTIVES To evaluate the predictive capacity of umbilical, cerebral and uterine artery Doppler in women admitted for preeclampsia (PE). METHODS 190 consecutive singleton pregnancies admitted with PE were included. Umbilical, cerebral and uterine artery Dopplers were performed. The association with adverse perinatal outcome was evaluated from 2 x 2 tables and multivariately by logistic regre...

BACKGROUND AND PURPOSE The objective of this study was to examine clinical outcomes and recanalization rates in a multicenter cohort of stroke patients receiving intravenous tissue plasminogen activator by site of occlusion localized with bedside transcranial Doppler. Angiographic studies with intraarterial thrombolysis suggest more proximal occlusions carry greater thrombus burden and benefit ...

Background: Nitric oxide synthase (NOS) activity is increased during hypertension and cerebral ischemia. NOS inactivation reduces stroke-induced cerebral injuries, but little is known about its role in blood-brain barrier (BBB) disruption and cerebral edema formation during stroke in acute hypertension. Here, we investigated the role of NOS inhibition in progression of edema formation and BBB d...

Objective: To evaluate the screening efficiency of ultrasound and Doppler measurements in the prediction of fetal anemia in alloimmunized pregnancies. Materials and Method: In a prospective study, 24 nonhydropic fetuses with red blood cell alloimmunization were evaluated with ultrasound and Doppler imaging. Middle cerebral artery peak systolic velocity, intrahepatic umbilical venous maximum vel...