Increased intracranial pressure was induced in anaesthetized dogs by application of liquid nitrogen to the dura mater. Intracranial pressure and cerebral blood flow were measured, together with arterial blood pressure and arterial and cerebral venous blood gases. Carbon dioxide was administered ...
PubMed Central
Absolute measurements of cerebral blood flow (CBF) are an important endpoint in studies of cerebral pathophysiology. Currently no accepted method exists for in vivo longitudinal monitoring of CBF with high resolution in rats and mice. Using three-dimensional Doppler Optical Coherence Tomography and cranial window ...
Local cerebral blood flow has been measured by quantitative autoradiography, employing (14C)iodoantipyrine as tracer, in rats killed half an hour after occlusion of the middle cerebral artery. The results were compared with pattern of local cerebral blood flow (CBF) in sham-operated rats and ...
Energy Citations Database
A dual-imaging modality is demonstrated for high-resolution quantitative imaging of local cerebral blood flow in the rat cortex by combining simultaneous spectral-domain Doppler optical coherence tomography (SDOCT) and full-field laser speckle contrast imaging (LSCI). Preliminary studies in tissue flow phantom and cocaine-induced ...
PubMed
Brain function depends on a steady and well-regulated supply of oxygenated blood. This absolute dependence is emphasized by the high incidence of mortality and morbidity associated with disorders of the cerebral circulation. In years past, no one dared ho...
National Technical Information Service (NTIS)
CONCLUSIONS: With inhalation of oxygen under excess pressure, combined with effective external counterpressure, the oxygen supply of the animal organism at an altitude of 30,000 m. is determined by the level of intrapulmonary pressure. With absolute press...
In 20 patients with ischemic cerebrovascular disease, classic migraine, or angiomas, we compared paired dynamic positron emission tomographic measurements of regional cerebral blood flow using both ({sup 15}O)water and ({sup 18}F)fluoromethane as tracers. Cerebral blood flow was also determined according to the ...
Critical cases of high blood pressure are common clinical occurrences that may account for as many as 25% of all medical emergencies. About 75% of these increases in blood pressure can be judged as hypertensive urgencies, 25% are even hypertensive emergency situations. Nevertheless, only less than 1% of the hypertensive population experiences hypertensive ...
Understanding the pathophysiology of paediatric head trauma is essential for rational acute management. It has been proposed that the response to severe head injury in children differs from that in adults, with increased cerebral blood flow (cerebral hyperaemia) representing the most common cause of raised intracranial pressure, but ...
Near infrared spectroscopy (NIRS) is a relatively new method which is suitable for monitoring oxygenation in blood and tissue in the brain of the fetus and the neonate. The technique involves in-vivo determination of the absorption of light in the wavelength range 775 to 900 nm through such tissue and converting such changes in absorbance to provide information about the ...
NASA Astrophysics Data System (ADS)
The capability of a miniaturized probe to measure local cerebral blood flow in a continuous and quantitative manner is described. The incorporation of thermal conductivity measurements using the isothermal principle with the hydrogen clearance method allows calibration of the thermal conductivity component in absolute terms. Evaluation ...
Exposure to microgravity alters the distribution of body fluids and the degree of distension of cranial blood vessels, and these changes in turn may provoke structural remodelling and altered cerebral autoregulation. Impaired cerebral autoregulation has been documented following weightlessness simulated by head-down bed rest in humans, ...
... in the present study, significantly decreased cerebral edema and preserved both electrocortical activity and cerebral blood flow in cortex exposed to ...
DTIC Science & Technology
The authors examined effects of hypothermia on cerebral metabolic rate and cerebral blood flow in anesthetized, newborn pigs (1-4 days old). Cerebral blood flow (CBF) was determined with 15-{mu}m radioactive microspheres. Regional CBF ranged from 44 to 66 ml{center dot}min{sup {minus}1}{center ...
... Abstract : Cerebral angiography was performed on 20 rhesus monkeys, and the systemic blood pressure of these and 4 additional animals was ...
The short half-life of /sup 15/O led early observers to believe that it was unsuitable for use as a biological tracer. However, initial studies with this nuclide demonstrated its potential usefulness for in vivo, regional physiologic measurements. Subsequently, techniques were developed to measure cerebral blood flow (CBF), blood ...
... Title : The Effect of Intracisternal Phentolamine on Cerebral Blood Flow after Simulated Subarachnoid Hemorrhage. Descriptive ...
... Title : EFFECTS OF METHYL ALCOHOL ON CEREBRAL BLOOD FLOW AND METABOLISM: OBSERVATIONS DURING AND AFTER ACUTE ...
Absolute cerebral perfusion parameters were obtained by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) carried out using different contrast-agent administration protocols. Sixteen healthy volunteers underwent three separate DSC-MRI examinations each, receiving single-dose (0.1 mmol/kg b.w.) gadobutrol, double-dose gadobutrol and ...
The goal of this study was to elucidate the association between the development of periventricular white matter lucency and autoregulation of cerebral blood flow in hypertensive patients through the arteriovenous oxygen saturation difference method. We studied 51 hypertensive patients who had previously suffered from minor strokes (lacunar infarction, 43; ...
The effect of the angiotensin-converting enzyme (ACE) inhibitor captopril on regional cerebral blood flow (rCBF) was studied in 12 patients within 5 days after their first acute stroke. rCBF was studied by xenon-133 inhalation and single-photon emission computed tomography (SPECT) scan before and 1 h after oral administration of 25 mg captopril. No ...
Sixty regional cerebral blood flow measurements were performed on 4 normal volunteers, 7 epileptics, and 40 cerebrovascular disorders using intravenously injected N-isopropyl-(I-123)p-iodoamphetamine (123I-IMP) and single photon emission computed tomography with rotating gamma camera. Arterial blood sampling was combined for obtaining ...
We developed a novel imaging technique that provides real-time two-dimensional maps of the absolute partial pressure of oxygen and relative cerebral blood flow in rats by combining phosphorescence lifetime imaging with laser speckle contrast imaging. Direct measurement of blood oxygenation based on phosphorescence ...
Brain computed tomography perfusion imaging in acute stroke may help guide therapy. However, the perfusion thresholds defining potentially salvageable (penumbra) and irreversibly injured (infarct core) tissue require further validation. The aim of this study was to validate infarct core and penumbra perfusion thresholds in a rodent stroke model by developing and optimising perfusion computed ...
Good estimates of total cerebral blood flow can be obtained by a technique somewhat analogous to that of externally estimating cardiac output volume rate. Radioiodinated human scrum albumin is pulse-injected into a carotid artery. The pulse of activity is recorded as it passes through the torcula Herophili, a venous sinus that normally drains a ...
To evaluate the risk of temporary or permanent internal carotid artery occlusion. In 156 patients intraarterial balloon test occlusion in combination with a stable xenon-enhanced CT cerebral blood flow study was performed before radiologic or surgical treatment. All 156 patients passed the clinical balloon test occlusion and underwent a xenon study in ...
Laser-Doppler flowmetry (LDF), a new method allowing instantaneous, continuous, and noninvasive measurements of microcirculatory blood flow in a small tissue sample, was evaluated for its accuracy in monitoring regional cerebral blood flow (rCBF) in the cortical microcirculation after focal cerebral ischemia. ...
... IMMUNIZATION, ORGANOPHOSPHATES, BLOOD CIRCULATION, SYMPATHETIC NERVOUS SYSTEM, CYTOCHEMISTRY, CEREBRUM ...
... Descriptors : *BLOOD CIRCULATION, *BLOOD PRESSURE, *CEREBRUM, VELOCITY, FRACTALS, BRAIN, VARIATIONS, PHYSIOLOGICAL ...
... Colbrie W, Wahlgren NG, and Jogestrand T. Carotid artery blood flow and middle cerebral artery blood flow velocity during physical exercise. ...
Although several reports on the clinical usefulness of N-isopropyl-(/sup 123/I)p-iodoamphetamine (IMP) in the diagnosis of cerebral disease have appeared in the literature, quantitative, noninvasive measurements of regional cerebral blood flow with this method pose difficulties because cerebral IMP uptake not only ...
We have examined sensitivity and specificity of pseudocontinuous arterial spin labeling (PCASL) to detect global and regional changes in cerebral blood flow (CBF) in response to two different psychoactive drugs. We tested alcohol and morphine in a placebo-controlled, double-blind randomized study in 12 healthy young men. Drugs were administered ...
Four very low birth weight, very premature infants were monitored during a 12� postural elevation using diffuse correlation spectroscopy (DCS) to measure microvascular cerebral blood flow (CBF) and transcranial Doppler ultrasound (TCD) to measure macrovascular blood flow velocity in the middle cerebral artery. ...
Lesion Volumes Type of Image or Map Cerebral Blood Volume Cerebral Blood Flow Tracer Mean Transit Time Cerebral Blood Volume, Relative Cerebral Blood Flow, and Mean Tissue Transit Time1 PURPOSE: To investigate additional information ...
E-print Network
Sequential changes in cerebral blood flow as well as in regional blood flow to the brain (brain stem, cerebellum, hypothalamus, white matter and grey matter) were measured in unanesthetized dogs subjected to gradual prolonged hemorrhage according to a protocol which stimulates the most commonly encountered type of clinical hemorrhagic ...
An experimental method for determining local cerebral blood flow (CBF1) within the area of supply of a major cerebral artery is described, using xenon-133. Utilizing anatomic-radiologic correlates, the territories of the anterior and middle cerebral arter...
Cerebral blood flow (CBF) reactivity monitoring is an appropriate primary parameter to evaluate cerebral resuscitation due to a systemic or regional cerebral injury leading to possible irreversible brain injury. Use of the electrical impedance method to e...
The method of Reinmuth et al for determining cerebral blood flow (CBF) (Arch. Neurol., 12:49-66, 1965) has been adapted for use on dogs. Measurements of CBF, cerebral vascular resistance (CVR) and cerebral oxygen and glucose consumptions were made at rect...
... Pagination or Media Count : 18. Descriptors : *BRAIN, *BLOOD VESSELS, *BLOOD CIRCULATION, BLOOD PRESSURE, CARBON DIOXIDE. ...
... Descriptors : *BLOOD CIRCULATION, *BLOOD ANALYSIS, BRAIN, PULSE RATE, WOUNDS AND INJURIES, PATHOLOGY, ACCELERATED ...
... Descriptors : (*FEVERS, BLOOD CIRCULATION), (*BLOOD CIRCULATION, BRAIN), MEASUREMENT, DOGS, RESPONSE(BIOLOGY), BODY ...
PURPOSE: To evaluate changes in cerebral hemodynamics after carotid stenting of symptomatic carotid artery in the patients who underwent ischemic stroke caused by carotid artery stenosis. METHODS: Twenty patients with unilateral symptomatic carotid artery stenosis received brain computer tomography perfusion (CTP) scan a week before and a week after carotid artery stenting. ...
... brain volumes are critically affected by barbiturate anesthesia and ... analysis, Polarographic analysis, Rare gases, Barbiturates, Primates, Cerebral ...
... wall may balloon out forming an aneurysm. A cerebral aneurysm may enlarge until it bursts, sending blood throughout ...
MedlinePLUS
... area within the vessel wall. If a cerebral (brain) aneurysm ruptures, the escaping blood within the brain may ... or death. A person who has a ruptured cerebral aneurysm may complain of the sudden onset of "the ...
We retrospectively examined regional cerebral blood flow values in 78 patients in the stabilized phase of stroke to evaluate the consistency of lateralization compared with computed tomographic imaging. Examinations were performed using the xenon-133 inhalation technique, and the data were processed and displayed by a computer-assisted system of our own ...
The initial validation of the brief inhalation method to measure cerebral oxygen extraction fraction (OEF) with positron emission tomography (PET) was performed in non-human primates with predominantly normal cerebral oxygen metabolism (CMRO2). Sensitivity analysis by computer simulation, however, indicated that this method may be subject to increasing ...
Autoregulation of cerebral blood flow (ACBF) under orthostatic tests (OT) was estimated in acute experiments on rabbits and cats under local anesthesia according to changes of perfusion pressure (PP) in carotid arteries, cerebral blood flow, pressure in t...
A functional form for the vascular concentration of MRI contrast agent after intravenous bolus injection was developed that can be used to model the concentration at any vascular site at which contrast concentration can be measured. The form is based on previous models of blood circulation, and is consistent with previously measured data at long post-injection times, when the ...
... Accession Number : ADA539636. Title : Urine Test Strips to Exclude Cerebral Spinal Fluid Blood. Descriptive Note : Journal article. ...
... 15. SUBJECT TERMS Cerebral blood flow, autoregulation, carotid flow, rheoencephalogram, pig 16. SECURITY CLASSIFICATION OF: 17. ...
Polarographic analysis on blood and cerebral tissue oxygenation in dogs during breathing of rarefied
NASA Technical Reports Server (NTRS)
... LC Hsu, and WY Sheng, "Transfer function analysis of cerebral hemodynamics in patients with carotid stenosis," J. Cereb. Blood Flow Metab., vol. ...
... Accession Number : AD0769187. Title : Local Cerebral Blood Flow Utilizing Xenon-133,. Corporate Author : ARMED FORCES ...
... 1. Blood flow in the cerebellum, basal ganglia, brain stem, and right and left hemispheres resembled global cerebral blood flow (see Table I). ...
... Accession Number : ADA090426. Title : Effects of Low Power Microwaves on the Local Cerebral Blood Flow of Conscious Rats,. ...
Cerebral blood flow (CBF) velocity and cranial fluid volume, which is defined as the total volume of
... inertial reaction of equal but opposite force (G) to displace organs and blood ... G-LOC occurs with a critical reduction in cerebral blood flow which has ...
A primary focus of neurointensive care is the prevention of secondary brain injury, mainly caused by ischemia. A noninvasive bedside technique for continuous monitoring of cerebral blood flow (CBF) could improve patient management by detecting ischemia before brain injury occurs. A promising technique for this purpose is diffuse correlation spectroscopy ...
The significance of fluid metabolism among the patients with cerebral infarction has barely mentioned in the literature despite the several reports suggesting the potential risk of reduced hydration status for the development of cerebral infarction. The aim of the this study is to explore the validity of the presumable relationship between hydration status ...
Regional quantitation of selected areas on PET images of brain studies provides numerical information about cerebral blood flow or local metabolism. To ensure accurate recovery of the absolute values within a region-of-interest (ROI), the well-known golden rule is to use ROI sizes at least equal to 2xFWHM of the spatial resolution of ...
Diabetic ketoacidosis (DKA) is a state of severe insulin deficiency, either absolute or relative, resulting in hyperglycemia and ketonemia. Although possibly underappreciated, up to 10% of cases of intracerebral complications associated with an episode of DKA, and/or its treatment, in children and youth are due to hemorrhage or ischemic brain infarction. Systemic inflammation ...
Cerebral atrial natriuretic peptide (ANP), which is generated in the brain, has functions in the regulation of brain water and electrolyte balance, blood pressure and local cerebral blood flow, as well as in neuroendocrine functions. However, cerebral ANP clearance is still poorly understood. ...
The Bookend technique is a magnetic resonance imaging (MRI) dynamic susceptibility contrast method that provides reliable quantitative measurement of cerebral blood flow (CBF) and cerebral blood volume (CBV). The quantification is patient specific, is derived from a steady-state measurement of CBV, and is obtained ...
In 200 autopsies of stroke cases, there were 99 cerebral hemorrhages including hypertensive cerebral hemorrhage 78, cerebral blood vessel anomalies 7, anemia 5, leukemia 4, tuberculous meningitis 2, septicemic, cerebral hemorrhage 1, severe jaundice compl...
A study using radioactive microspheres for the investigation of cerebral blood flow during acceleration is described. Details of a technique for the blunt dissection of cerebral tissues are included. Results of flow studies at 3 and 5 G sub z acceleration...
There is a growing body of evidence that increases in neuronal activity occur during rapid eye movement (REM) sleep. Cerebral metabolic rate is also thought to increase, based on indirect evidence that cerebral blood flow (CBF) is elevated during REM slee...
It has been hypothesized that acute lesions of the brain enlarge through an autodestructive process. Serotonin (5HT), a potent cerebral vasoconstrictor, is believed by some to mediate the process by reducing cerebral blood flow (CBF) in tissue surrounding...
The pathophysiology of migraine remains poorly understood. Sumatriptan has been reported to increase flow velocities in large cerebral arteries, consistent with a vasoconstrictive effect. We report data from a study of tissue cerebral blood flow (CBF) in ...
We report dynamic CT perfusion imaging assessment of hemodynamics in a patient with a high-grade cerebral glioma and compare our results to those of previously published studies. PMID:12719953
... Title : The Effect of an Experimental Missile Wound to the Brain on Brain Electrolytes, Regional Cerebral Blood Flow and Blood Brain Barrier ...
... Descriptors : *BLOOD CIRCULATION, *CAROTID ARTERIES, EXPERIMENTAL DATA, MONITORING, HUMANS, TEST METHODS, ELECTRICAL ...
... Descriptors : (*RESPIRATION, HIGH ALTITUDE), OXYGEN, BLOOD, BRAIN, PRESSURE, OXYGEN CONSUMPTION, PRESSURE BREATHING ...
... tissue that is susceptible to injury from low oxygen or low blood sugar. � Inadequate oxygen or blood flow to the brain in the ...
... have, by chemical and ... ACETYLCHOLINE, *ATROPINE, *BLOOD CIRCULATION, *CHOLINERGIC ... CORTEX, CEREBRUM, CHEMICALS, CHOLINE ...
To investigate the vasoconstrictor effect of 5-hydroxytryptamine (5-HT1B/1D) receptor agonists for migraine treatment, changes in cerebral blood flow (CBF) and blood volume induced by rizatriptan were assessed by positron emission tomography (PET). Eleven healthy volunteers underwent PET studies before and after rizatriptan ...
