AIMS/BACKGROUND While the retinal lesions of sickle cell retinopathy have been well documented, their pathogenesis remains unclear. The purpose of this study was (1) to compare macular blood flow velocity in patients with sickle cell disease and controls, and (2) to determine in sickle cell patients the relation between macular blood flow velocity and red blood cell density. METHODS Macular b...

BACKGROUND AND PURPOSE Current transcranial Doppler criteria for vasospasm after aneurysmal subarachnoid hemorrhage are not age specific. We analyzed the effect of age on cerebral blood flow velocity changes after subarachnoid hemorrhage and constructed an age-adjusted predictive model of cerebral blood flow velocity in subarachnoid hemorrhage patients. METHODS We identified patients with ane...

OBJECTIVES The purpose of this study was to assess rest and stress atrial coronary blood flow (CBF) velocity and flow reserve. BACKGROUND Because of the limitations of the methods used until now for assessing myocardial perfusion (MP) in the small mass of atrial tissue, data are lacking for human atrial MP. METHODS Seventeen patients with suitable coronary anatomy underwent CBF velocity mea...

Wieneke, Heinrich, Clemens von Birgelen, Michael Haude, Holger Eggebrecht, Stefan Möhlenkamp, Axel Schmermund, Dirk Böse, Christoph Altmann, Thomas Bartel, and Raimund Erbel. Determinants of coronary blood flow in humans: quantification by intracoronary Doppler and ultrasound. J Appl Physiol 98: 1076– 1082, 2005. First published October 29, 2004; doi:10.1152/ japplphysiol.00724.2004.—The direct...

Observations on blood velocity in the middle cerebral artery using transcranial Doppler ultrasound and on the ipsilateral internal carotid artery flow volume were obtained during periods of transient, rapid blood flow variations in 7 patients. Five patients were investigated after carotid endarterectomy. A further 2 patients having staged carotid endarterectomy and open heart surgery were inves...

BACKGROUND AND PURPOSE Cardiovascular disease risk predicts cognitive decline although the mechanisms underpinning this association remain unclear. Increasing cardiovascular risk may impair cerebral blood flow predisposing to cerebrovascular damage, cognitive decline, and dementia. METHODS This study examined the association between the Framingham General Cardiovascular Risk Profile and cereb...

We present a new method for the quantitative estimation of blood flow velocity, based on the use of the Radon transform. The specific application is for measurement of blood flow velocity in the retina. Our modified fundus camera uses illumination from a green LED and captures imagery with a high-speed CCD camera. The basic theory is presented, and typical results are shown for an in vitro flow...

We have developed a novel phase-resolved optical coherence tomography (OCT) and optical Doppler tomography (ODT) system that uses phase information derived from a Hilbert transformation to image blood flow in human skin with fast scanning speed and high velocity sensitivity. Using the phase change between sequential scans to construct flow-velocity imaging, this technique decouples spatial reso...

The key to surviving hypoxia is to protect the brain from energy depletion. The epaulette shark (Hemiscyllium ocellatum) is an elasmobranch able to resist energy depletion and to survive hypoxia. Using epi-illumination microscopy in vivo to observe cerebral blood flow velocity on the brain surface, we show that cerebral blood flow in the epaulette shark is unaffected by 2 h of severe hypoxia (0...

A hemodynamic model for pulsatile fluid flow in a pressurized thin-walled elastic tube was applied for the computation of volumetric blood flow and velocity profiles for a given set of system parameters at any selected location along the umbilical artery. The velocity profiles over one heart cycle provide the fetal blood flow velocity waveforms (FVW) from which the usual Doppler indexes (DI) ca...