Introduction: Nitroglycerin is a fast-acting drug that rapidly dilates coronary arteries and thus increases blood flow to these vessels, and increases the blood flow through the lateral vessels to low blood areas. It also reduces both end diastolic pressure and volume of the left ventricular. However, the effect of nitroglycerin on the circulation hemodynamic is not known. Caro...

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...

introduction : cerebral autoregulation (ca) and mean cerebral blood flow velocity in males and females are still under controversy. the present study was scheduled to address the effect of sex on these parameters. materials and methods : the present study was interventional and performed on 30 healthy volunteers (15 males aging from 20-30 yrs and mean age of 23.9±3 years old and 15 females agin...

PURPOSE The aim of this study was to assess vascular changes and blood flow abnormalities in the common carotid arteries of patients with head and neck cancers after external radiotherapy, using color Doppler ultrasonography. METHODS We studied 24 patients treated with external radiotherapy for various head and neck cancers. In order to study the acute effects of irradiation on common carotid...

Introduction:In this study, a non-invasive method based on consecutive ultrasonic image processing is introduced to assess time rate changes of the carotid artery wall displacement, velocity and acceleration in the longitudinal direction. The application of these parameters to discriminate healthy and atherosclerotic arteries was evaluated. Methods:Longitudinal displacement rate of common ...

background: common carotid arterial stiffness can be assessed during carotid arterial ultrasonography, but its association with brachial stiffness, a well-defined cardiovascular risk factor, has not been clarified. the aim of this study was to examine the relationship between common carotid artery and brachial artery stiffness. methods: the static pressure-strain elastic modulus of the common c...

PURPOSE The aim of this study was to introduce and implement a noninvasive method to derive the carotid artery pressure waveform directly by processing diagnostic sonograms of the carotid artery. METHODS Ultrasound image sequences of 20 healthy male subjects (age, 36±9 years) were recorded during three cardiac cycles. The internal diameter and blood velocity waveforms were extracted from cons...

background: pulse wave velocity (pwv) is widely used for estimating the stiffness of an artery. v arious invasive and non-invasive methods have been developed to determine pwv over the years. in the present research , the non-invasive estimation of the pwv of large arteries was used as an index for arterial stiffness. methods: a dynamic model based on the navier-stokes equations coupled to elas...

Transcranial Doppler ultrasonography can map the changes in blood velocity that result from stenosis or occlusion of the middle cerebral artery. To evaluate patterns of collateral blood flow in disease of the middle cerebral artery stem, we used both cerebral angiography and transcranial Doppler ultrasonography to study the systolic blood velocities in both anterior cerebral arteries in 10 cons...