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Mean cerebral blood flow

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https://www.readbyqxmd.com/read/29339351/high-target-vs-low-target-blood-pressure-management-during-cardiopulmonary-bypass-to-prevent-cerebral-injury-in-cardiac-surgery-patients-a-randomized-controlled-trial
#1
Anne G Vedel, Frederik Holmgaard, Lars S Rasmussen, Annika Langkilde, Olaf B Paulson, Theis Lange, Carsten Thomsen, Peter Skov Olsen, Hanne Berg Ravn, Jens C Nilsson
Background -Cerebral injury is an important complication following cardiac surgery with the use of cardiopulmonary bypass (CPB). The rate of overt stroke after cardiac surgery is 1-2%, whereas silent strokes, detected by diffusion-weighed magnetic resonance imaging (DWI), are found in up to 50% of patients. It is unclear if a higher versus a lower blood pressure during cardiopulmonary bypass reduces cerebral infarction in these patients. Methods -In a patient- and assessor-blinded randomized trial, we allocated patients to a higher (70-80 mmHg) or lower (40-50 mmHg) target for mean arterial pressure by the titration of norepinephrine during cardiopulmonary bypass...
January 16, 2018: Circulation
https://www.readbyqxmd.com/read/29337197/brain-perfusion-alterations-in-tick-borne-encephalitis-preliminary-report
#2
Zuzanna Tyrakowska-Dadełło, Eugeniusz Tarasów, Dariusz Janusek, Anna Moniuszko-Malinowska, Joanna Zajkowska, Sławomir Pancewicz
BACKGROUND: Magnetic resonance imaging (MRI) changes in Tick-borne encephalitis (TBE) are nonspecific and pathophysiologic mechanisms leading to their formation remain unclear. This study aimed to investigate brain perfusion in TBE patients using dynamic susceptibility contrast (DSC) MR perfusion imaging. METHODS: MRI scans were performed in 12 patients in the acute phase, 3-5days after TBE diagnosis, with conventional MR images and DSC-MRI perfusion studies. Cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and time to peak (TTP) parametric maps were created...
January 11, 2018: International Journal of Infectious Diseases: IJID
https://www.readbyqxmd.com/read/29333725/chemoreflex-function-and-brain-blood-flow-during-upright-posture-in-men-and-women
#3
Christopher Hazlett, Heather Edgell
Orthostatic intolerance is more common in women than men, and some studies have found that women in the early follicular (EF) phase of the menstrual cycle experience the greatest feelings of lightheadedness. Chemoreflex function while supine or upright was investigated to determine the potential contribution of ventilatory control to these phenomena. Men (n = 13) and women (n = 14) were tested while supine and 70° upright (head-up tilt [HUT]) and given: (1) normoxia or (2) hypercapnia (5% CO2 ). Women were tested during the EF phase (days 2-5) and the midluteal phase (ML; days 18-24)...
January 2018: Physiological Reports
https://www.readbyqxmd.com/read/29331554/potential-role-of-transfontanelle-ultrasound-for-infants-undergoing-modified-blalock-taussig-shunt
#4
Eun-Hee Kim, Ji-Hyun Lee, In-Kyung Song, Hee-Soo Kim, Young-Eun Jang, Woong-Han Kim, Jae-Gun Kwak, Jin-Tae Kim
OBJECTIVE: Transfontanelle ultrasound is a noninvasive method for assessing cerebral blood flow in neonates and infants. The authors applied this technique as a point-of-care tool, before and after modified Blalock-Taussig shunt procedure, to evaluate cerebral perfusion. DESIGN: Retrospective, observational study. SETTING: Tertiary care children's hospital. PARTICIPANTS: Ten infants undergoing modified Blalock-Taussig shunt procedure...
December 11, 2017: Journal of Cardiothoracic and Vascular Anesthesia
https://www.readbyqxmd.com/read/29330635/hypotension-due-to-spinal-anesthesia-influences-fetal-circulation-in-primary-caesarean-sections
#5
K Lato, I Bekes, Peter Widschwendter, T W P Friedl, W Janni, F Reister, G Froeba, U Friebe-Hoffmann
PURPOSE: Hypotension due to spinal anesthesia is a well-known side effect in pregnant women receiving caesarean section. Little is known about its impact on fetal blood circulation. METHODS: 40 women with uncomplicated singleton term pregnancies prepared for caesarean section were prospectively evaluated by Doppler sonography before and immediately after spinal anesthesia. RESULTS: In 90% of the women, blood pressure significantly decreased after spinal anesthesia and 42...
January 12, 2018: Archives of Gynecology and Obstetrics
https://www.readbyqxmd.com/read/29315770/diffusion-sensitivity-of-3d-grase-in-arterial-spin-labeling-perfusion
#6
Xiang He, Kenneth Wengler, Mark E Schweitzer
PURPOSE: To evaluate the role of true diffusion and flow-related pseudodiffusion in cerebral blood flow (CBF) quantification using arterial spin labeling (ASL) with single-shot or segmented 3D gradient and spin echo (GRASE) readouts. THEORY: The extended phase graph (EPG) algorithm, originally designed to model the effects of T1 /T2 relaxation and true diffusion in MRI acquisitions utilizing multiple refocusing RF pulses, was augmented (aEPG). This augmentation accounted for flow-related pseudodiffusion attenuation of intravascular MRI signal in the k-space domain during 3D-GRASE acquisition, which leads to blur along the partition direction in the image domain...
January 7, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29304217/elevated-markers-of-inflammation-are-associated-with-longitudinal-changes-in-brain-function-in-older-adults
#7
Kristen N Warren, Lori L Beason-Held, Olga Carlson, Josephine M Egan, Yang An, Jimit Doshi, Christos Davatzikos, Luigi Ferrucci, Susan M Resnick
Background: Chronic inflammation has been linked to memory and other cognitive impairments, as well as Alzheimer's disease. Here, we investigate the association between inflammatory markers and changes in brain activity measured by regional cerebral blood flow (rCBF) to assess the relationship between inflammation and brain function in older individuals. Methods: Annual 15O water resting-state positron emission tomography (PET) scans collected over a 5-year period were assessed in 138 cognitively normal older participants (77 males; mean age at baseline = 71...
January 3, 2018: Journals of Gerontology. Series A, Biological Sciences and Medical Sciences
https://www.readbyqxmd.com/read/29288284/transit-time-corrected-arterial-spin-labeling-technique-aids-to-overcome-delayed-transit-time-effect
#8
Tae Jin Yun, Chul-Ho Sohn, Roh-Eul Yoo, Kyung Mi Kang, Seung Hong Choi, Ji-Hoon Kim, Sun-Won Park, Moonjung Hwang, R Marc Lebel
PURPOSE: This study aimed to evaluate the usefulness of transit time corrected cerebral blood flow (CBF) maps based on multi-phase arterial spin labeling MR perfusion imaging (ASL-MRP). METHODS: The Institutional Review Board of our hospital approved this retrospective study. Written informed consent was waived. Conventional and multi-phase ASL-MRPs and dynamic susceptibility contrast MR perfusion imaging (DSC-MRP) were acquired for 108 consecutive patients. Vascular territory-based volumes of interest were applied to CBF and time to peak (TTP) maps obtained from DSC-MRP and CBF maps obtained from conventional and multi-phase ASL-MRPs...
December 29, 2017: Neuroradiology
https://www.readbyqxmd.com/read/29288194/increased-middle-cerebral-artery-mean-blood-flow-velocity-index-after-stroke-thrombectomy-indicates-increased-risk-for-intracranial-hemorrhage
#9
Markus Kneihsl, Kurt Niederkorn, Hannes Deutschmann, Christian Enzinger, Birgit Poltrum, Renate Fischer, Daniela Thaler, Christina Hermetter, Gerit Wünsch, Franz Fazekas, Thomas Gattringer
BACKGROUND AND PURPOSE: Cerebral hyperperfusion has been related to the risk of intracranial hemorrhage (ICH) in stroke patients after vessel recanalization therapy. We hypothesized that after successful mechanical thrombectomy for acute anterior circulation stroke, hemodynamics detectable by transcranial Duplex (TCD) sonography would vary, and that increased blood flow velocities would be associated with ICH. METHODS: We retrospectively identified all ischemic stroke patients with successful endovascular recanalization for anterior circulation vessel occlusion (Thrombolysis in Cerebral Infarction 2b-3) between 2010 and 2017...
December 28, 2017: Journal of Neurointerventional Surgery
https://www.readbyqxmd.com/read/29273948/icp-curve-morphology-and-intracranial-flow-volume-changes-a-simultaneous-icp-and-cine-phase-contrast-mri-study-in-humans
#10
Mårten Unnerbäck, Johnny T Ottesen, Peter Reinstrup
BACKGROUND: The intracranial pressure (ICP) curve with its different peaks has been extensively studied, but the exact physiological mechanisms behind its morphology are still not fully understood. Both intracranial volume change (ΔICV) and transmission of the arterial blood pressure have been proposed to shape the ICP curve. This study tested the hypothesis that the ICP curve correlates to intracranial volume changes. METHODS: Cine phase contrast magnetic resonance imaging (MRI) examinations were performed in neuro-intensive care patients with simultaneous ICP monitoring...
December 22, 2017: Acta Neurochirurgica
https://www.readbyqxmd.com/read/29260927/substrain-and-sex-dependent-differences-in-stroke-vulnerability-in-c57bl-6-mice
#11
Liang Zhao, Megan K Mulligan, Thaddeus S Nowak
The C57BL/6 mouse strain is represented by distinct substrains, increasingly recognized to differ genetically and phenotypically. The current study compared stroke vulnerability among C57BL/6 J (J), C57BL/6JEiJ (JEiJ), C57BL/6ByJ (ByJ), C57BL/6NCrl (NCrl), C57BL/6NJ (NJ) and C57BL/6NTac (NTac) substrains, using a model of permanent distal middle cerebral artery and common carotid artery occlusion. Mean infarct volume was nearly two-fold smaller in J, JEiJ and ByJ substrains relative to NCrl, NJ and NTac (N-lineage) mice...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/29249541/cerebrospinal-fluid-biomarkers-of-alzheimer-s-disease-are-associated-with-carotid-plaque-score-and-hemodynamics-in-intra-and-extra-cranial-arteries-on-ultrasonography
#12
Minoru Kouzuki, Masaya Nagano, Tetsuya Suzuki, Yuto Katsumata, Syouta Nakamura, Ayumi Takamura, Katsuya Urakami
Carotid plaque score (PS) and hemodynamic abnormalities in intra- and extra-cranial arteries are related to Alzheimer's disease (AD) progression. As these parameters are measured conveniently and non-invasively by ultrasonography, we examined their association with cerebral spinal fluid (CSF) AD biomarkers amyloid β (Aβ) and phosphorylated tau (p-tau). Carotid PS, mean flow velocity (MFV) in multiple intra- and extra-cranial arteries, CSF Aβ42 and p-tau, neurocognitive function (assessed by the Mini-Mental State Examination and Alzheimer's Disease Assessment Scale-cognitive subscale, Japanese version), and blood lipids (total cholesterol, HDL cholesterol, LDL cholesterol, and triglyceride) were measured in AD patients (n = 42), mild cognitive impairment patients (n = 20), and cognitively normal controls (n = 18)...
December 14, 2017: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
https://www.readbyqxmd.com/read/29243981/assessment-of-intracranial-venous-blood-flow-after-subarachnoid-hemorrhage-a-new-approach-to-diagnose-vasospasm-with-transcranial-color-coded-duplex-sonography
#13
Florian Connolly, Stephan J Schreiber, Christoph Leithner, Georg Bohner, Peter Vajkoczy, José M Valdueza
OBJECTIVE Transcranial color-coded duplex sonography (TCCS) is a reliable tool that is used to assess vasospasm in the M1 segment of the middle cerebral artery (MCA) after subarachnoid hemorrhage (SAH). A distinct increase in blood flow velocity (BFV) is the principal criterion for vasospasm. The MCA/internal carotid artery (ICA) index (Lindegaard Index) is also widely used to distinguish between vasospasm and cerebral hyperperfusion. However, extracranial ultrasonography assessment of the neck vessels might be difficult in an intensive care unit...
December 15, 2017: Journal of Neurosurgery
https://www.readbyqxmd.com/read/29239696/compression-garments-and-cerebral-blood-flow-influence-on-cognitive-and-exercise-performance
#14
Brittany A Smale, Joseph M Northey, Disa J Smee, Nathan G Versey, Ben Rattray
This study aimed to describe the effect of compression garments on middle cerebral artery blood flow velocity (MCAv) in relation to cognitive and exercise performance whilst cycling. In a randomised-controlled-cross-over design, 15 well-trained male cyclists were recruited to participate in three identical trials wearing loose fitting shorts (control), low-grade, or medium-grade compression garments. The protocol involved four 8 min increments of cycling at 30%, 50%, 70%, and 85% maximal power output and a 4 km time-trial...
December 14, 2017: European Journal of Sport Science
https://www.readbyqxmd.com/read/29238007/diagnostic-performance-of-arterial-spin-labeling-for-grading-nonenhancing-astrocytic-tumors
#15
Delgerdalai Khashbat, Masafumi Harada, Takashi Abe, Mungunbagana Ganbold, Seiji Iwamoto, Naoto Uyama, Saho Irahara, Youichi Otomi, Teruyoshi Kageji, Shinji Nagahiro
PURPOSE: We evaluated the utility of arterial spin labeling (ASL) imaging of tumor blood flow (TBF) for grading non-enhancing astrocytic tumors. MATERIALS AND METHODS: Thirteen non-enhancing astrocytomas were divided into high-grade (n = 7) and low-grade (n = 6) groups. Both ASL and conventional sequences were acquired using the same magnetic resonance machine. Intratumoral absolute maximum TBF (TBFmax), absolute mean TBF (TBFmean), and corresponding values normalized to cerebral blood flow (TBFmax and TBFmean ratios) were measured...
December 12, 2017: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/29235099/variations-from-morning-to-afternoon-of-middle-cerebral-and-umbilical-artery-blood-flow-and-fetal-heart-rate-variability-and-fetal-characteristics-in-the-normally-developing-fetus
#16
Tehila Avitan, Ari Sanders, Ursula Brain, Dan Rurak, Tim F Oberlander, Ken Lim
OBJECTIVE: To determine if there are changes in maternal uterine blood flow, fetal brain blood flow, fetal heart rate variability, and umbilical blood flow between morning (AM) and afternoon (PM) in healthy, uncomplicated pregnancies. STUDY DESIGN: In this prospective study, 68 uncomplicated singleton pregnancies (mean 35 + 0.7 weeks gestation) underwent a standard observational protocol at both 08:00 (AM) and 13:30 (PM) of the same day. This protocol included Doppler measurements of uterine, umbilical, and fetal middle cerebral artery (MCA) volume flow parameters (flow, HR, peak systolic velocity [PSV], PI, and RI) followed by computerized cardiotocography...
December 13, 2017: Journal of Clinical Ultrasound: JCU
https://www.readbyqxmd.com/read/29234724/lower-cerebral-blood-flow-in-subjects-with-alzheimer-s-dementia-mild-cognitive-impairment-and-subjective-cognitive-decline-using-two-dimensional-phase-contrast-magnetic-resonance-imaging
#17
Jolien F Leijenaar, Ingrid S van Maurik, Joost P A Kuijer, Wiesje M van der Flier, Philip Scheltens, Frederik Barkhof, Niels D Prins
Introduction: In this cross-sectional study, we aimed to detect differences in cerebral blood flow (CBF) between subjects with Alzheimer's disease (AD), mild cognitive impairment (MCI), and subjective cognitive decline (SCD), using two-dimensional phase-contrast magnetic resonance imaging. Methods: We included 74 AD patients (67 years, 51% female), 36 MCI patients (66 years, 33% female), and 62 patients with SCD (60 years, 32% female) from the Amsterdam Dementia Cohort...
2017: Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring
https://www.readbyqxmd.com/read/29234089/impact-of-treatment-on-resting-cerebral-blood-flow-and-metabolism-in-obsessive-compulsive-disorder-a-meta-analysis
#18
A L van der Straten, D Denys, G A van Wingen
Neurobiological models of obsessive-compulsive disorder (OCD) posit that its clinical symptoms such as repetitive thoughts and behaviors are related to hyperactivity in the cortico-striato-thalamo-cortical (CSTC) circuit. Small scale neuroimaging studies have shown that treatment of OCD is associated with reduced activity across different brain structures within this circuitry. We performed the first meta-analysis of positron emission tomography (PET) and single photon emission computed tomography (SPECT) studies that investigated cerebral blood flow or glucose metabolism in patients with OCD before and after pharmacological or psychological treatment...
December 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29229240/brain-functional-and-perfusional-alterations-in-schizophrenia-an-arterial-spin-labeling-study
#19
Ícaro A F Oliveira, Tiago M Guimarães, Roberto M Souza, Antônio C Dos Santos, João Paulo Machado-de-Sousa, Jaime E C Hallak, Renata F Leoni
Schizophrenia is a severe mental disorder that affects the anatomy and function of the brain, with an impact on one's thoughts, feelings, and behavior. The purpose of the study was to investigate cerebral blood flow (CBF) and brain connectivity in a group of patients with schizophrenia. Pseudo-continuous arterial spin labeling (pCASL) images were acquired from 28 patients in treatment and 28 age-matched healthy controls. Mean CBF and connectivity patterns were assessed. Schizophrenia patients had decreased CBF in the bilateral frontal pole and superior frontal gyrus, right medial frontal gyrus, triangular and opercular parts of the inferior frontal gyrus, posterior division of the left supramarginal gyrus, superior and inferior divisions of the left lateral occipital cortex, and bilateral occipital pole...
December 5, 2017: Psychiatry Research
https://www.readbyqxmd.com/read/29224052/arterial-input-function-in-a-dedicated-slice-for-cerebral-perfusion-measurements-in-humans
#20
Elias Kellner, Irina Mader, Marco Reisert, Horst Urbach, Valerij Gennadevic Kiselev
OBJECT: We aimed to modify our previously published method for arterial input function measurements for evaluation of cerebral perfusion (dynamic susceptibility contrast MRI) such that it can be applied in humans in a clinical setting. MATERIALS AND METHODS: Similarly to our previous work, a conventional measurement sequence for dynamic susceptibility contrast MRI is extended with an additional measurement slice at the neck. Measurement parameters at this slice were optimized for the blood signal (short echo time, background suppression, magnitude and phase images)...
December 9, 2017: Magma
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