Purpose:To characterize total retinal blood flow in a group of healthy subjects.Methods:64 healthy volunteers were included in this study. Retinal venous diameters were measured using a Dynamic Vessel Analyzer (DVA). Retinal blood velocities were measured using bi-directional laser Doppler velocimetry (LDV). All vessels with a diameter of more than 60 ...

BACKGROUND: -Systemic-pulmonary collateral (SPC) flow occurs commonly in single ventricle patients after superior cavo-pulmonary connection, with unclear clinical significance. We sought to evaluate the association between SPC flow and acute post-Fontan clinical outcomes using a novel method of quantifying SPC flow by cardiac magnetic resonance (CMR). METHODS AND RESULTS: -All ...

This paper investigates the main characteristics of the magneto-hemodynamic (MHD) response for application as a biomarker of vascular blood flow. The induced surface potential changes of a volunteer exposed to a 3 T static B0 field of a magnetic resonance imaging (MRI) magnet were measured over time at multiple locations by ...

AIM: We designed this study to investigate if immunoglobuline G-Pertussis toxin (IgG-PT) against Bordetella pertussis in umbilical cord blood can reliably be determined in dried blood spots on filter paper (Guthrie) cards. PATIENTS AND METHODS: We prospectively included 129 mothers and their newborns born in a general hospital in the ...

BACKGROUND: New insights into potential adverse effects of banked blood and improved infectious surveillance have led to questions regarding the utility of preoperative autologous blood donation. METHODS: A retrospective chart review of 153 patients undergoing abdominal free flap breast reconstruction was performed with the goal of determining the effect of ...

PURPOSE: The aim of this study was to investigate the value of commonly examined laboratory measurements, including ammonia and lactate, in predicting neurologic outcome of out-of-hospital cardiac arrest (OHCA) patients treated with therapeutic hypothermia (TH). METHODS: This was a retrospective cohort study of patients with a return of spontaneous circulation ...

Neurocognition is impaired in Chronic Fatigue Syndrome (CFS). We propose that impairment relates to postural cerebral hemodynamics. 25 CFS and 20 control subjects underwent incremental upright tilt at 0°, 15°, 30°, 45°, 60°, and 75° with continuous measurement of arterial blood pressure and cerebral blood flow velocity (CBFv). We used ...

The objective of this study was to determine whether changes in carboxyhaemoglobin (COHb) saturation following carbon monoxide (CO) rebreathing can be accurately detected by pulse CO-oximetry in order to determine blood volume. Noninvasive measurements of carboxyhaemoglobin saturation (SpCO) were continuously monitored by pulse CO-oximetry before, during and following 2 min ...

The Hall effect has been applied to electrolyte flow measurement. It has been proven that Hall voltage does not depend on electrolyte concentration; however, there is a linear relationship between Hall voltage and flow velocity. Obtained results for electrolyte allow us to suppose that Hall effect can be used to ...

The success of percutaneous interventions on stenotic hemodialysis prosthetic grafts and autogenous fistulas is assessed by comparing vessel diameter before and after treatment. These changes do not correlate with gold standard access blood flow (ABF) measurements obtained during hemodialysis. The AngioFlow (AngioDynamics, Inc, Queensbury, New York) calculates real-time blood flow ...

BACKGROUND:: Intraoperative transfusion decisions generally are guided by blood loss estimation and periodic invasive hemoglobin measurement. Continuous hemoglobin measurement by pulse cooximetry (pulse hemoglobin; Rainbow® SET Pulse CO-Oximeter, Masimo Corporation, Irvine, CA) has good agreement with laboratory hemoglobin in healthy volunteers and could aid transfusion decision-making. Because intraoperative physiology may ...

BackgroundPerfusion magnetic resonance imaging (MRI) is increasingly used in the evaluation of brain tumors. Relative cerebral blood volume (rCBV) is usually obtained by dynamic susceptibility contrast (DSC) MRI using normal appearing white matter as reference region. The emerging perfusion technique arterial spin labelling (ASL) presently provides measurement only of cerebral ...

Transcranial Doppler ultrasonography is the most commonly used method of cerebrovascular blood flow velocity measurement, but it is subject to certain technical and anatomic limitations. The Doppler velocity guidewire measures blood flow velocity within any vessel during cerebral angiography, overcoming these limitations. We report the first use of this guidewire ...

There is growing evidence supporting the role of inflammation in early brain injury and cerebral vasospasm following subarachnoid hemorrhage (SAH). Matrix metalloproteinases (MMPs) are released by inflammatory cells and can mediate early brain injury via disruption of the extracellular matrix and mediate vasospasm by cleaving endothelin-1 into vasoactive fragments. We ...

RATIONALE AND OBJECTIVES: To assess the effect of measurement time on blood flow (BF), blood volume (BV), and k-trans-values (flow extraction product) in patients undergoing volume perfusion computed tomography (VPCT) for lung cancer. MATERIALS AND METHODS: This prospective study was approved by our local Research Ethics Committee and informed consent was ...

Each year, more than 4 million patients receive a blood transfusion in the United States to control symptoms associated with anemia, coagulopathy, thrombocytopenia, or some combination thereof. In each of these cases, the physician and the patient must weigh the potential benefits of the transfusion along with the associated risks. ...

In 2005, The Joint Commission set about assessing the need for performance measures associated with the provision of blood products. Through a rigorous process, seven patient blood management performance measures were created. These measures incorporated a measure requiring transfusion consent; three measures requiring the combination of a laboratory value and ...

PURPOSE: To investigate blood flow and transit time measurement, using the pseudo-random arterial modulation (PRAM). MATERIALS AND METHODS: PRAM is based on a pseudo-random sequence of inversions and noninversions of the arterial blood at a labeling plane inferior to the imaging plane. To accomplish this, a pseudo-continuous tagging is used ...

Purpose:To determine whether flow velocity can be measured by using projection data from computed tomographic (CT) scans obtained during contrast material injection in a phantom model.Materials and Methods:The authors constructed a 12.7-mm-diameter single-channel flow phantom with constant water flow velocity settings of 25.3, 43.9, and 70.5 cm/sec. For each flow ...

WT1 levels may be a useful predictor of leukemia free survival (LFS) following treatment of acute myeloid leukemia (AML). We report a retrospective study in which levels of WT1 expression from patients with de novo AML were measured from bone marrow and peripheral blood at diagnosis, post-induction, post-consolidation and relapse. ...

Background:Monitoring hemoglobin levels in the operating room currently requires repeated blood draws, several steps, and a variable time delay to receive results. Consequently, blood transfusion management decisions may be delayed or made before hemoglobin results become available. The ability to measure hemoglobin continuously and noninvasively may enable a more rapid ...

Purpose:  To assess the agreement among three masked examiners on central retinal artery (CRA) and ophthalmic artery (OA) blood flow velocity measurements performed with colour Doppler imaging (CDI) in healthy volunteers. Methods:  The study included 30 eyes of 15 healthy volunteers. Prior to the study, all examiners underwent intensive CDI ...

Abstract Objetive: We studied intrauterine-growth-restricted (IUGR) fetuses with absent or reversed umbilical artery end-diastolic flow velocity (EDF) in order to evaluate the benefit of antenatal steroid therapy. Perinatal outcomes after betamethasone were evaluated where end diastolic flow returned (group I), compared with data from fetuses with persistent absent-reverse end diastolic ...

The primary objective of this investigation was to quantitatively identify which training variables result in the greatest strength and hypertrophy outcomes with lower body low intensity training with blood flow restriction (LI-BFR). Searches were performed for published studies with certain criteria. First, the primary focus of the study must have ...

We simultaneously measured respiratory, cerebrovascular and cardiovascular responses to 10-min of isoxic hypoxia at three constant CO(2) tensions in 15 subjects. We observed four response patterns, some novel, for ventilation, middle cerebral artery blood flow velocity, heart rate and mean arterial blood pressure. The occurrence of the response patterns was ...

The development of atherosclerosis has been shown to correlate with regions of low wall shear stress and seemingly reduced mass transport. The local tortuosity of the arteries and local secondary flow oscillation also seem to be negatively correlated with the local occurrence of the disease. However there is currently no ...

The radiocephalic arteriovenous fistula remains the method of choice for haemodialysis access. In order to assess their suitability for fistula formation, the radial arteries and cephalic veins were examined preoperatively by ultrasound colour flow scanner in conjunction with a pulse-generated run-off system. Intraoperative blood flow was measured after construction of ...

The degree of inflammation is the keystone of therapy management in rheumatoid arthritis and other arthritides. The assessment of synovial perfusion using power Doppler ultrasound is an important point in the quantification of the joint inflammation but it is limited by the subjectivity of the vascularization grading and incapacity to ...

Quantitative arterial spin labeling (ASL) estimates of cerebral blood flow (CBF) during oxygen inhalation are important in several contexts, including functional experiments calibrated with hyperoxia and studies investigating the effect of hyperoxia on regional CBF. However, ASL measurements of CBF during hyperoxia are confounded by the reduction in the longitudinal ...

Changes in the exchange rate of water across the blood-brain barrier, denoted k(w) , may indicate blood-brain barrier dysfunction before the leakage of large-molecule contrast agents is observable. A previously proposed approach for measuring k(w) is to use diffusion-weighted arterial spin labeling to measure the vascular and tissue fractions of ...

OBJECTIVE: The volemic status of a patient can be determined by measuring mean systemic filling pressure (Pmsf). Pmsf is obtained from the venous return curve, i.e. the relationship between central venous pressure (Pcv) and blood flow. We evaluated the feasibility and precision of Pmsf measurement. METHODS: In ten piglets we ...

Blood flow should be measured to monitor conditions of patients with implantable artificial hearts continuously and noninvasively. We have developed a noninvasive miniaturized mass-flow meter using a curved cannula for an axial flow blood pump. The mass-flow meter utilized centrifugal force generated by the mass-flow rate in the curved cannula. ...

Online estimation of cerebral autoregulation (CA) may be advantageous in neurosurgical and neurointensive care units. Data from transcranial Doppler, and continuous arterial blood pressure are readily available at high temporal resolution and may be used to assess CA. There are currently no methods for nonlinear, noninvasive, online assessment of CA. ...

We report on the first measurement of the triangular v_{3}, quadrangular v_{4}, and pentagonal v_{5} charged particle flow in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV measured with the ALICE detector at the CERN Large Hadron Collider. We show that the triangular flow can be described in terms of the initial spatial anisotropy ...

BACKGROUND: Quantification of abdominal blood flow is essential for a variety of gastrointestinal and hepatic topics such as liver transplantation or metabolic flux measurement, but those need to be performed during surgery. It is not clear whether Duplex Doppler Ultrasound during surgery or MRI before surgery is the tool to ...

We have developed a laser Doppler velocimeter (LDV) for measuring velocity distributions in blood vessels. We converted a transmission-based LDV into a reflection-based LDV to make it suitable for clinical applications. The velocity distribution image of a serpentine flow channel obtained could be qualitatively explained by the numerical results. Finally, ...

Purpose: The right internal jugular (RIJ) vein is preferred for placement of long-term venous catheters (CVC) for hemodialysis (HD). Use of left IJ vein potentially depletes the access site for arteriovenous fistula (AVF) or arteriovenous graft (AVF) placement because of the high rates of central venous stenosis. The right external ...

Purpose: The purpose of this study was to perform bench and clinical testing of a catheter-based intravascular system capable of measuring blood flow in hemodialysis vascular accesses during endovascular procedures. Methods: We tested the Transonic ReoCath Flow Catheter System which uses the thermodilution method. A simulated vascular access model was ...

In this study we evaluate the influences of optical property assumptions on near-infrared diffuse correlation spectroscopy (DCS) flow index measurements. The optical properties, absorption coefficient (µ(a)) and reduced scattering coefficient (µ(s)'), are independently varied using liquid phantoms and measured concurrently with the flow index using a hybrid optical system combining ...

Dynamic contrast-enhanced ultrasound (DCE-US) and the method of disruption replenishment has been used for the past 10 years to measure flow noninvasively in the microcirculation. However, the method's perceived poor reproducibility remains a major impediment to widespread clinical acceptance. Poor reproducibility can be attributed, in part, to the curve fitting ...

OBJECTIVE:: The clinical value of stroke volume variations to assess intravascular fluid status in critically ill patients is well known. Electrical impedance tomography is a noninvasive monitoring technology that has been primarily used to assess ventilation. We investigated the potential of electrical impedance tomography to measure left ventricular stroke volume ...

OBJECTIVE: Holodiastolic arterial blood flow is associated with pathological conditions. Nevertheless, we have observed that lifting the arm at an angle greater than the horizontal causes holodiastolic arterial blood flow in the brachial artery in normal patients. Thus, we decided to assess the frequency and characteristics of this phenomenon. METHOD: ...

Contrast-enhanced ultrasound (CEUS) has demonstrated utility in the monitoring of blood flow in tissues, organs and tumors. However, current CEUS methods typically provide only relative image-derived measurements, rather than quantitative values of blood flow in milliliters/minute per gram of tissue. In this study, CEUS derived parameters of blood flow are ...

BACKGROUND:: The blood supply of microvascular free flaps is rated as very critical, particularly in the first postoperative days. Only a timely recognition of a complication and its treatment can ensure the survival of the flap. To quantify the postoperative perfusion dynamics, we measured the oxygen supply and blood flow ...

Background: In farm animal practice, determination of blood glucose concentration under field conditions is often necessary. Objective: As there is no portable glucose meter device developed for use in farm animals, the analytical accuracy of a portable glucometer designed for people was evaluated for its use in cattle and sheep. ...

Comparability and reproducibility of different near-infrared spectroscopy devices measuring regional tissue oxygen saturation remain poor. Aim of the present study was to compare values and reproducibility of cerebral∕peripheral "tissue-oxygenation-index" (TOI; NIRO 300, Hamamatsu(®), Japan) with cerebral∕peripheral "regional-oxygen-saturation" (rSO; INVOS5100, Somanetics(®), USA), and to analyze the influence of quality criteria. Methods: ...

The Cypriot mouflon (Ovis orientalis ophion), a once almost extirpated species of wild sheep, is under strict surveillance because it can be threatened by likely transmission of pathogenic bacteria, such as Anaplasma spp., Rickettsia spp., and Coxiella burnetii, primarily from domestic ungulates. We collected 77 blood samples from Cypriot mouflons ...

The present study was carried out to determine the prevalence of Theileria annulata in large ruminants in Southern Punjab (Pakistan). Blood samples were collected from 144 large ruminants, consisting of 105 cattle and 39 buffaloes, from six districts of Southern Punjab including Multan, Layyah, Muzaffar Garh, Bhakar, Bahawalnagar, and Vehari. ...

ABSTRACT: BACKGROUND: Malaria pigment (haemozoin, Hz) has been the focus of diverse research efforts. However, identification of Hz-containing leukocytes or parasitized erythrocytes is usually based on microscopy, with inherent limitations. Flow cytometric detection of depolarized Side-Scatter is more accurate and its adaptation to common bench top flow cytometers might allow ...

Abstract. Polymerase chain reaction (PCR) has been shown to be more sensitive in detecting low-level parasitemia than conventional blood film microscopy. We estimated the prevalence of congenital malaria using nested PCR amplification of the small subunit 18S RNA gene to detect low-level parasitemia and identify Plasmodium species in 204 mother-neonate ...