TFc T + + = (8) and hematocrit salineICA systemicICA ICA FF HCTF HCT + = (9) where FICA is blood flow rate in the ipsilateral ICA and Fsaline is the saline flow rate. Inflowing blood through the other source vessels, "Analysis of ...

Magnetic Resonance Angiography was used to measure the volumetric blood flow rates entering the common carotid artery (CCA), and exiting through the external (ECA) and internal (ICA) carotid arteries. Fourier decomposition of the pulsatile wave through the internal carotid artery shows that that the amplitude of the harmonics ...

Hemispheric mean cerebral blood flow (CBF), together with its CO2 reactivity in response to hyperventilation, was investigated in 18 patients with transient ischemic attacks (TIAs) by intraarterial 133Xe injection method in a subacute-chronic stage of the clinical course. In 8 patients, the lesion responsible for symptoms was regarded as unilateral ...

The mechanism underlying the plateau or relative decrease in cerebral blood flow (CBF) during maximal incremental dynamic exercise remains unclear. We hypothesized that cerebral perfusion is limited during high-intensity dynamic exercise due to a redistribution of carotid artery blood flow. To identify the ...

Internal carotid artery (ICA) trapping can be used for treating intracranial giant aneurysm, blood blister-like aneurysms and ICA rupture during the surgery. We present a novel ICA trapping technique which can be used with insufficient collaterals flow via anterior communicating artery (AcoA) ...

Brain single photon emission computed tomographic (SPECT) images acquired after injecting Tc-99m-HMPAO into the internal carotid artery (ICA) during an intracarotid amobarbital procedure (IAP SPECT) provide anatomical information on the blood flow distribution from the ICA. In this study, probabilistic maps of the ...

Analyzing Transient Turbulence in a Stenosed Carotid Artery by Proper Orthogonal Decomposition in a carotid arterial bifurcation with a stenosed internal carotid artery (ICA). The geometrical model employ computational fluid dynamics (CFD) to investigate blood flow in a carotid artery, which has

BACKGROUND:: The degree of carotid artery stenosis has traditionally been used as a marker of hemodynamic compromise and increased stroke risk. However, the hemodynamic effect of carotid atherosclerotic plaque length on cerebral blood flow has not been previously studied. OBJECTIVE:: To determine if carotid plaque length in addition to degree of stenosis ...

Radionuclide cerebral blood flow (CBF) examinations of 48 patients with atherosclerosis, 18 with occlusion and 30 with stenosis of the internal carotid artery (ICA) were correlated with their respective cerebral angiograms. The following results were obtained. Flow was visually unilaterally diminished in 29 (60%) ...

Background Arterial spin labelling (ASL) is an MRI technique for measuring perfusion at the brain tissue level. The aim of the study was to investigate cerebrovascular reactivity (CVR) at brain-tissue level in patients with an internal carotid artery (ICA) occlusion by combining ASL-MRI with a vascular challenge, and determine whether the CVR varies within the perfusion ...

Purpose: To establish reference values of the ratios of flow velocity in the middle cerebral artery (V_MCA) and the terminal portion of the internal carotid artery (V_tICA) to flow velocity in the extracranial portion of internal carotid artery ...

Near-infrared spectroscopy (NIRS) is a method for noninvasive estimation of cerebral hemodynamic changes. Principal component analysis (PCA) and independent component analysis (ICA) can be used for decomposing a set of signals to underlying components. Our objective is to determine whether PCA or ICA is more efficient in identifying and removing scalp ...

We described 9 consecutive patients who underwent operative carotid artery exploration with attempted carotid endarterectomy (CEA) for symptomatic internal carotid artery (ICA) occlusion. Indications for this surgery based on vascular imaging included segmental occlusion of the proximal ICA and also extensive occlusion of the distal ...

Few studies have investigated the relationship between the degree of stenosis of the internal carotid artery (ICA) and cerebrovascular reserve (CVR). This study examined that relationship. A total of 56 ICAs in 43 patients were included. Computed tomography scan or magnetic resonance imaging showed no evidence of infarction in any of these patients. Both ...

The blood flow dynamics of a stenosed, subject-specific, carotid bifurcation were numerically simulated using the spectral element method. Pulsatile inlet conditions were based on in vivo color Doppler ultrasound measurements of blood velocity. The results demonstrated the transitional or weakly turbulent state of the ...

A 54-year-old male presented with intermittent massive hemorrhage from recurrent oropharyngeal cancer. The angiogram showed the encasements at the main trunk of the left internal carotid artery (ICA) and external carotid artery (ECA). Transcatheter arterial embolization (TAE) of the ECA with gelatin sponge particles and microcoils was performed. However, hemorrhage recurred ...

Background and purpose: Stenting is one of the treatment options for carotid artery stenosis. To show the effectiveness of the treatment, computational fluid dynamics (CFD) has been performed for the last several decades. The inlet/outlet boundary conditions are important in CFD, and several researchers have used various inlet/outlet boundary conditions. In this paper, we compared the ...

of system resolution and the spill-over of left ventricle, right ventricle and myocardium caused variables correspond to major cardiac components such as left ventricle, right ventricle, and myocardium for transformation of all dynamic data. Two planes of short axis images were summed in order to extract myocardium

INTRODUCTION The segmentation of perfusion images is essential for tissue-specific quantitative assessment of cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transit time (MTT) values. Average CBV, CBF, MTT values expressed per tissue type can help assess the severity of pathology and the progression of ...

To develop a simple, relatively noninvasive small-animal model of reversible regional cerebral ischemia, we tested various methods of inducing infarction in the territory of the right middle cerebral artery (MCA) by extracranial vascular occlusion in rats. In preliminary studies, 60 rats were anesthetized with ketamine and different combinations of vessels were occluded; blood ...

Quantification of cerebral blood flow (CBF) with dynamic susceptibility contrast (DSC) magnetic resonance imaging (MRI) requires the determination of the arterial input function (AIF). The segmentation of surrounding tissue by manual selection is error-prone due to the partial volume artifacts. Independent component analysis (ICA) has ...

Blister-like internal carotid artery (ICA) aneurysms are known for their fragile and thin-walled morphology associated with a high risk of intraprocedural rupture. Neurosurgical and endovascular options are illustrated on three exemplary cases reviewing the diagnostic and therapeutic implications of these special aneurysms. A 49-year-old woman was admitted with subarachnoid ...

Near-infrared spectroscopy (NIRS) is a noninvasive and real- time method for monitoring oxy-(HbO2) and deoxyhemoglobin (Hb) in tissue, an is suitable for intraoperative monitoring. In this study, NIRS monitoring was performed on 10 patients during carotid cross-clamping. The data were analyzed with a theoretical cerebral hemoglobin model developed to identify an ischemic pattern using NIRS ...

This study investigates the oxygen mass transport in the region around the human carotid bifurcation, particularly addressing the effects of bifurcation geometry and pulsatile blood flow on the oxygen transport between the blood flow and artery wall tissue, coupled with the metabolic oxygen consumption and oxygen ...

Arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) with image acquisition at multiple inversion times is a noninvasive ASL technique able to compensate for spatial heterogeneities in transit times caused by collateral blood flow in patients with severe stenosis of the cerebropetal blood vessels. Our aim was to ...

Arterial spin labeling (ASL) perfusion magnetic resonance imaging (MRI) with image acquisition at multiple inversion times is a noninvasive ASL technique able to compensate for spatial heterogeneities in transit times caused by collateral blood flow in patients with severe stenosis of the cerebropetal blood vessels. Our aim was to ...

Balloon test occlusion (BTO) of the internal carotid artery (ICA) combined with cerebral blood flow (CBF) study has proved to be a sensitive test for prediction of the outcome of permanent vessel occlusion. In this study, we evaluated the acute changes in regional CBF during BTO under hypotension in order to examine the possible risk ...

The authors performed transcranial Doppler ultrasonography (TCD) during internal carotid artery (ICA) balloon test occlusion (BTO) and observed changes in mean flow velocity (Vm) in the middle cerebral artery (MCA), and pulsatility index (PI) while monitoring the stump pressure (Sp) of the internal carotid artery (ICA), and neurologic ...

Previous studies of white matter signal hyperintensity (WMSH) on T2-weighted MRI (magnetic resonance imaging) have shown it to be related to decreased cerebral blood flow (CBF). However, there have been few studies on the relationship of WMSH and the internal carotid blood flow (CaBF). Doppler ultrasound sonography ...

A method for the analysis of fatigue parameters has been rarely researched in VDT operation. Up to now, fatigue was evaluated by changing of biological information. If signals regarding fatigue are detected, fatigue can be measured. The purpose of this study proposed experiment and analysis method to extract parameters related to fatigue from the biological information during VDT operation using ...

Diffuse optical tomography (DOT) methods observe hemodynamics in the brain by measuring light transmission through the scalp, skull, and brain. Thus, separating signals due to heart pulsations, breathing movements, and systemic blood flow fluctuations from the desired brain functional responses is critical to the fidelity of the derived maps. Herein, we ...

PURPOSE: The purpose of this study was to report the preliminary experience of a modified transcervical carotid angioplasty and stenting (CAS) technique with filter protection and flow reversal only during filter placement in patients unsuitable for transfemoral CAS and at high risk for carotid endarterectomy (CEA). PATIENTS AND METHODS: Twenty-five of 132 patients, aged 75 to ...

To understand cerebral blood circulation after long-term exposure to carbon disulfide (CS2), four patients with encephalopathy and polyneuropathy, who had worked in a viscose rayon plant, were studied. Clinical and laboratory examinations, including brain magnetic resonance images (MRI), computed tomography (CT), CT perfusion, and CT angiography, were carried out. Brain CT and ...

BACKGROUND: A routine aspiration method in filter-protected carotid artery stenting (CAS) has been reported recently in which the proximal internal carotid artery (ICA) blood column was aspirated using an aspiration catheter after postdilatation regardless of flow state on digital subtraction angiography. We examined the debris ...

The protein inhibitor of carbonic anhydrase (CA), pICA, was localized in pig tissues by an immunohistochemical technique, using rabbit antipICA IgG. Staining for pICA was found in liver sinusoids and kidney glomeruli, where phagocytic cells are located, i.e. Kupffer and mesangial cells, respectively. pICA was not ...

We present a patient with a symptomatic, high-grade stenosis of the internal carotid artery (ICA) and contraindication for open surgery. Endovascular treatment was attempted, but stent placement was not possible. In view of good collateral flow to the related hemisphere, embolization of the stenosis of the ICA with Guglielmi detachable ...

BACKGROUND AND PURPOSE: TCD screening is widely used to identify children with SCD at high risk of stroke. Those with high mean flow velocities in major brain arteries have increased risk of stroke. Thus, our aim was to establish reference values of interhemispheric differences and ratios of blood flow Doppler parameters in the ...

We report a case of congenital absence of the left internal carotid artery (ICA) that presented with left-sided facial numbness. On MRI of the brain, occlusion of the left cavernous ICA was suggested. On colour Doppler ultrasound (CDS), the left ICA was not visualized and the ipsilateral common carotid artery (CCA) showed normal ...

Local cerebral blood flow (LCBF) and local tissue: blood partition coefficient (L lambda) values were measured for small volumes of gray or white matter by CT CBF. Single compartment analysis was used but fitted to infinity in normal volunteers aged between 20 to 100 years (N . 20). Hemispheric LCBF and L lambda values were compared to ...

While it is widely appreciated that volumetric blood flow rate (VFR) dynamics change with age, there has been no detailed characterization of the typical shape of carotid bifurcation VFR waveforms of older adults. Toward this end, retrospectively gated phase contrast magnetic resonance imaging was used to measure time-resolved VFR waveforms proximal and ...

While it is widely appreciated that volumetric blood flow rate (VFR) dynamics change with age, there has been no detailed characterization of the typical shape of carotid bifurcation VFR waveforms of older adults. Towards this end, retrospectively gated phase contrast magnetic resonance imaging was used to measure time-resolved VFR waveforms proximal and ...

Indications for the clinical use of transcranial Doppler (TCD) continue to expand while scanning protocols and quality of reporting vary between institutions. Based on literature analysis and extensive personal experience, an international expert panel started the development of guidelines for TCD performance, interpretation, and competence. The first part describes complete diagnostic spectral ...

In spite of a wide choice of pacemakers, there are some problems in making more rational clinical decisions for individual patients since mode selection and programming is usually performed on the basis of a clinical hunch. The aim of this study was to measure the differences in carotid flow in patients with a pacemaker programmed in the dual chamber and in the single chamber ...

A SPECT (single photon emission computed tomography) study in internal carotid artery (ICA) occlusion was performed in 6 patients. The validity of iodoamphetamine (IMP) SPECT study in the evaluation of cerebral blood flow (CBF) or neurologic function is still controversial. In this study, the authors showed several cases in whom SPECT ...

We present a case of spontaneous recanalization of the internal carotid artery (ICA) that occurred in a 51-year-old male patient. The occlusion of the right ICA was asymptomatic and was detected incidentally during imaging of the opposite carotid artery. The patient underwent neuroradiologic analysis and a tapered, flame-like occlusion suggestive of the ...

OBJECTIVE: True understanding of carotid bifurcation pathophysiology requires a detailed knowledge of the hemodynamic conditions within the arteries. Data on carotid artery hemodynamics are usually based on simplified, computer-based, or in vitro experimental models, most of which assume that the velocity profiles are axially symmetric away from the carotid bulb. Modeling accuracy and, more ...

Intraoperative monitoring of cerebral hemodynamics during carotid endarterectomy (CEA) provides essential information for detecting cerebral hypoperfusion induced by temporary internal carotid artery (ICA) clamping and post-CEA hyperperfusion syndrome. This study tests the feasibility and sensitivity of a novel dual-wavelength near-infrared diffuse correlation spectroscopy ...

Intraoperative monitoring of cerebral hemodynamics during carotid endarterectomy (CEA) provides essential information for detecting cerebral hypoperfusion induced by temporary internal carotid artery (ICA) clamping and post-CEA hyperperfusion syndrome. This study tests the feasibility and sensitivity of a novel dual-wavelength near-infrared diffuse correlation spectroscopy ...

Using monochromatic synchrotron radiation, we performed microangiography in C57BL/6J mice and investigated their vasculature after unilateral and bilateral carotid artery occlusion. Bilateral occlusion of the carotid artery was made by a ligation of the left common carotid artery followed by a ligation of the right internal carotid artery (ICA) two days later (n=12). Five days ...

Focal injury to the brain or retina is a frequent complication of drug delivery to the internal carotid artery (ICA) and may be due to poor mixing of the drug with blood at the infusion site. Rhesus monkeys were studied to determine whether phased drug delivery during diastole from a modified pulsatile angiographic injector would improve drug mixing in ...

... Tests on Straked Delta Wings", 18th ICAS ... on a Semi-Span Delta Wing Model, Oscillating in ... 16 Geurts, EGM, "Flow Visualization and Particle Image ...

Assessing the hemodynamic status of the brain and its variations in response to stimulations is required to understand the local cerebral circulatory mechanisms. Dynamic contrast enhanced imaging of cerebral microvasculature provides information that can be used in understanding physiology of cerebral diseases. Bolus tracking is used to extract characteristic parameters that quantify local ...

A 64-year-old man complaining of pulsatile headache was admitted. Imaging studies revealed a near-total occlusion of the right proximal internal carotid artery (ICA) with slow antegrade flow into the distal ICA. Right cerebral flow was supplied by collateral flow through the posterior ...

... Descriptors : , AORTA, BLOOD CIRCULATION, BLOOD PRESSURE, BLOOD VESSELS, CONTRACTION, CONTROL, KIDNEYS, PHYSIOLOGY ...

A blood pump that comprises a pump housing having a blood flow path therethrough, a blood inlet, and

ICAS2002 CONGRESS SIMULATION TECHNIQUES IN HYPERSONIC AEROTHERMODYNAMICS Vladimir V. Riabov Rivier College, Nashua, New Hampshire 03060, USA Keywords: hypersonic non-equilibrium rarefied-gas flows, aero- & thermodynamic coefficients Abstract Hypersonic viscous flows near simple-shape bodies (wedge, cone, disk, plate

In cerebral blood circulation, the interplay of arterial geometrical features and flow dynamics is thought to play a significant role in the development of aneurysms. In the framework of the Aneurisk project, patient-specific morphology reconstructions were conducted with the open-source software VMTK (www.vmtk.org) on a set of computational angiography ...

... ICA Join the ICA Donate Now Store ICA Facebook Causes Connect IC Facebook Community ICA on Twitter ICHelp YouTube Channel Interstitial ... ICA Join the ICA Donate Now Store ICA Facebook Causes Connect IC Facebook Community ICA ...

Observe blood flow and muscle contractions in each body segment of Lumbriculus variegates (observe the blood flow in each segment).

This study describes and evaluates a semi-automated method for prescribing an optimal imaging plane that is located as close as possible to the skull base, and is simultaneously nearly perpendicular to the four arteries leading blood to the brain (internal carotid arteries (ICAs) and vertebral arteries (VAs)). Such method will streamline and improve ...

... regulates blood flow from the heart into the aorta, the major blood vessel that brings blood to ... blood to flow from the heart to the aorta. It prevents the blood from flowing back from ...