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ASL and MRI

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https://www.readbyqxmd.com/read/28431859/mri-based-quantification-of-renal-perfusion-in-mice-improving-sensitivity-and-stability-in-fair-asl
#1
Fabian Tobias Gutjahr, Stephan Michael Günster, Thomas Kampf, Patrick Winter, Volker Herold, Wolfgang Rudolf Bauer, Peter Michael Jakob
PURPOSE: The importance of the orientation of the selective inversion slice in relation to the anatomy in flow-sensitive alternating inversion recovery arterial spin labeling (FAIR ASL) kidney perfusion measurements is demonstrated by comparing the standard FAIR scheme to a scheme with an improved slice selective control experiment. METHODS: A FAIR ASL method is used. The selective inversion preparation slice is set perpendicular to the measurement slice to decrease the unintended labeling of arterial spins in the control experiment...
April 18, 2017: Zeitschrift Für Medizinische Physik
https://www.readbyqxmd.com/read/28421854/reduction-of-bold-interference-in-pseudo-continuous-arterial-spin-labeling-towards-quantitative-fmri
#2
Geoffrey Warnock, Pinar S Özbay, Felix P Kuhn, Daniel Nanz, Alfred Buck, Andreas Boss, Cristina Rossi
Fluctuations in blood-oxygenation level dependent (BOLD) signal and perfusion affect the quantification of changes in cerebral blood flow (CBF), coupled to neuronal activity, in arterial spin labeling (ASL). Subtraction methods for control and labeled MR images (i.e. pair-wise, surround subtraction, and subtraction of sinc-interpolated images), postulated to mitigate this interference in pseudo-continuous ASL (pCASL), were evaluated by comparison with quantitative (15)O-water PET. At rest, a good agreement in the CBF values was found between PET and MRI for each of the subtraction methods...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28393659/variability-of-physiological-brain-perfusion-in-healthy-subjects-a-systematic-review-of-modifiers-considerations-for-multi-center-asl-studies
#3
Patricia Clement, Henk-Jan Mutsaerts, Lena Václavů, Eidrees Ghariq, Francesca B Pizzini, Marion Smits, Marjan Acou, Jorge Jovicich, Ritva Vanninen, Mervi Kononen, Roland Wiest, Egill Rostrup, António J Bastos-Leite, Elna-Marie Larsson, Eric Achten
Quantitative measurements of brain perfusion are influenced by perfusion-modifiers. Standardization of measurement conditions and correction for important modifiers is essential to improve accuracy and to facilitate the interpretation of perfusion-derived parameters. An extensive literature search was carried out for factors influencing quantitative measurements of perfusion in the human brain unrelated to medication use. A total of 58 perfusion modifiers were categorized into four groups. Several factors (e...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28393012/the-effect-of-repetitive-subconcussive-collisions-on-brain-integrity-in-collegiate-football-players-over-a-single-football-season-a-multi-modal-neuroimaging-study
#4
Semyon M Slobounov, Alexa Walter, Hans C Breiter, David C Zhu, Xiaoxiao Bai, Tim Bream, Peter Seidenberg, Xianglun Mao, Brian Johnson, Thomas M Talavage
The cumulative effect of repetitive subconcussive collisions on the structural and functional integrity of the brain remains largely unknown. Athletes in collision sports, like football, experience a large number of impacts across a single season of play. The majority of these impacts, however, are generally overlooked, and their long-term consequences remain poorly understood. This study sought to examine the effects of repetitive collisions across a single competitive season in NCAA Football Bowl Subdivision athletes using advanced neuroimaging approaches...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28383796/arterial-spin-labeling-mri-is-able-to-detect-early-hemodynamic-changes-in-diabetic-nephropathy
#5
José María Mora-Gutiérrez, Nuria Garcia-Fernandez, M Fernanda Slon Roblero, Jose A Páramo, F Javier Escalada, Danny Jj Wang, Alberto Benito, María A Fernández-Seara
PURPOSE: To investigate whether arterial spin labeling (ASL) MRI could detect renal hemodynamic impairment in diabetes mellitus (DM) along different stages of chronic kidney disease (CKD). MATERIALS AND METHODS: Three Tesla (3T) ASL-MRI was performed to evaluate renal blood flow (RBF) in 91 subjects (46 healthy volunteers and 45 type 2 diabetic patients). Patients were classified according to their estimated glomerular filtration rate (eGFR) as group I (eGFR > 60 mL/min/1...
April 6, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28374078/arterial-spin-labeling-based-z-maps-have-high-specificity-and-positive-predictive-value-for-neurodegenerative-dementia-compared-to-fdg-pet
#6
David Fällmar, Sven Haller, Johan Lilja, Torsten Danfors, Lena Kilander, Nelleke Tolboom, Karl Egger, Elias Kellner, Philip M Croon, Sander C J Verfaillie, Bart N M van Berckel, Rik Ossenkoppele, Frederik Barkhof, Elna-Marie Larsson
OBJECTIVE: Cerebral perfusion analysis based on arterial spin labeling (ASL) MRI has been proposed as an alternative to FDG-PET in patients with neurodegenerative disease. Z-maps show normal distribution values relating an image to a database of controls. They are routinely used for FDG-PET to demonstrate disease-specific patterns of hypometabolism at the individual level. This study aimed to compare the performance of Z-maps based on ASL to FDG-PET. METHODS: Data were combined from two separate sites, each cohort consisting of patients with Alzheimer's disease (n = 18 + 7), frontotemporal dementia (n = 12 + 8) and controls (n = 9 + 29)...
April 3, 2017: European Radiology
https://www.readbyqxmd.com/read/28355722/-a-clinical-analysis-of-5-patients-with-infratentorial-primary-angiitis-of-central-nervous-system
#7
L J Peng, H R Qian, L L Mao, D Y Xia, X K Qi
Objective: To explore the clinical characteristics of infratentorial primary angiitis in central nervous system(PACNS). Methods: A total of 5 cases diagnosed as infratentorial PACNS in the neurology department of Navy General Hospital of PLA in 2015 were enrolled in the study. The clinical, imaging and pathological data were collected and analyzed. Results: All the 5 cases were male with the median onset age of thirty-four. Five cases presented with dizziness, two with headache, three with walking unstable, two with facial numbness and one with dysarthria...
April 1, 2017: Zhonghua Nei Ke za Zhi [Chinese Journal of Internal Medicine]
https://www.readbyqxmd.com/read/28355354/cerebral-blood-flow-and-vasoreactivity-in-aging-an-arterial-spin-labeling-study
#8
R F Leoni, I A F Oliveira, O M Pontes-Neto, A C Santos, J P Leite
Regional cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) in young and elderly participants were assessed using pulsed arterial spin labeling (ASL) and blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) techniques in combination with inhalation of CO2. Pulsed ASL and BOLD-MRI were acquired in seventeen asymptomatic volunteers (10 young adults, age: 30±7 years; 7 elderly adults, age: 64±8 years) with no history of diabetes, hypertension, and neurological diseases. Data from one elderly participant was excluded due to the incorrigible head motion...
March 23, 2017: Brazilian Journal of Medical and Biological Research, Revista Brasileira de Pesquisas Médicas e Biológicas
https://www.readbyqxmd.com/read/28352082/a-normative-spatiotemporal-mri-atlas-of-the-fetal-brain-for-automatic-segmentation-and-analysis-of-early-brain-growth
#9
Ali Gholipour, Caitlin K Rollins, Clemente Velasco-Annis, Abdelhakim Ouaalam, Alireza Akhondi-Asl, Onur Afacan, Cynthia M Ortinau, Sean Clancy, Catherine Limperopoulos, Edward Yang, Judy A Estroff, Simon K Warfield
Longitudinal characterization of early brain growth in-utero has been limited by a number of challenges in fetal imaging, the rapid change in size, shape and volume of the developing brain, and the consequent lack of suitable algorithms for fetal brain image analysis. There is a need for an improved digital brain atlas of the spatiotemporal maturation of the fetal brain extending over the key developmental periods. We have developed an algorithm for construction of an unbiased four-dimensional atlas of the developing fetal brain by integrating symmetric diffeomorphic deformable registration in space with kernel regression in age...
March 28, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28342287/longitudinal-evaluation-of-perfusion-changes-in-acute-and-chronic-renal-allograft-rejection-using-arterial-spin-labeling-in-translational-mouse-models
#10
Katja Hueper, Martina Schmidbauer, Anja Thorenz, Jan H Bräsen, Marcel Gutberlet, Michael Mengel, Dagmar Hartung, Rongjun Chen, Martin Meier, Hermann Haller, Frank Wacker, Song Rong, Faikah Gueler
PURPOSE: To examine the longitudinal changes of renal perfusion due to acute and chronic renal allograft rejection by using arterial spin labeling (ASL) MRI in translational mouse models of isogenic and allogenic kidney transplantation (ktx). MATERIALS AND METHODS: Acute rejection was induced by allogenic ktx of C57BL/6 (B6)-kidney grafts to BALB/c-recipients with prolonged cold ischemia (CIT) of 60 minutes (n = 13). To induce chronic rejection BALB/c-kidneys were transplanted into B6-recipients with short CIT of 30 minutes (n = 22)...
March 25, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28323841/detection-of-crossed-cerebellar-diaschisis-in-hyperacute-ischemic-stroke-using-arterial-spin-labeled-mr-imaging
#11
Koung Mi Kang, Chul-Ho Sohn, Seung Hong Choi, Keun-Hwa Jung, Roh-Eul Yoo, Tae Jin Yun, Ji-Hoon Kim, Sun-Won Park
BACKGROUND AND PURPOSE: Arterial spin-labeling (ASL) was recently introduced as a noninvasive method to evaluate cerebral hemodynamics. The purposes of this study were to assess the ability of ASL imaging to detect crossed cerebellar diaschisis (CCD) in patients with their first unilateral supratentorial hyperacute stroke and to identify imaging or clinical factors significantly associated with CCD. MATERIALS AND METHODS: We reviewed 204 consecutive patients who underwent MRI less than 8 hours after the onset of stroke symptoms...
2017: PloS One
https://www.readbyqxmd.com/read/28323181/perioperative-changes-in-cerebral-perfusion-territories-assessed-by-arterial-spin-labeling-magnetic-resonance-imaging-are-associated-with-postoperative-increases-in-cerebral-blood-flow-in-patients-with-carotid-stenosis
#12
Daisuke Yamamoto, Kohkichi Hosoda, Yoshito Uchihashi, Atsushi Fujita, Takashi Sasayama, Masahiko Fujii, Kazuro Sugimura, Masaaki Kohta, Eiji Kohmura
OBJECTIVE: MRI technique known as Territorial ASL (TASL) allows for noninvasive visualization of their perfusion territories. The objective of this study was to use TASL to assess the relationship between perioperative changes in the perfusion territories of ICA and CBF after carotid revascularization. METHODS: In 32 patients, ICA perfusion volume (PV) and CBF were measured before and after CEA/CAS using TASL and SPECT, respectively. ICA flow was measured during CEA before and after reconstruction, using an electromagnetic flowmeter...
March 16, 2017: World Neurosurgery
https://www.readbyqxmd.com/read/28323164/mapping-the-pharmacological-modulation-of-brain-oxygen-metabolism-the-effects-of-caffeine-on-absolute-cmro2-measured-using-dual-calibrated-fmri
#13
Alberto Merola, Michael A Germuska, Esther Ah Warnert, Lewys Richmond, Daniel Helme, Sharmila Khot, Kevin Murphy, Peter J Rogers, Judith E Hall, Richard G Wise
This study aims to map the acute effects of caffeine ingestion on grey matter oxygen metabolism and haemodynamics with a novel MRI method. Sixteen healthy caffeine consumers (8 males, age = 24.7±5.1) were recruited to this randomised, double-blind, placebo-controlled study. Each participant was scanned on two days before and after the delivery of an oral caffeine (250mg) or placebo capsule. Our measurements were obtained with a newly proposed estimation approach applied to data from a dual calibration fMRI experiment that uses hypercapnia and hyperoxia to modulate brain blood flow and oxygenation...
March 17, 2017: NeuroImage
https://www.readbyqxmd.com/read/28319118/functional-mri-for-characterization-of-renal-perfusion-impairment-and-edema-formation-due-to-acute-kidney-injury-in-different-mouse-strains
#14
Susanne Tewes, Faikah Gueler, Rongjun Chen, Marcel Gutberlet, Mi-Sun Jang, Martin Meier, Michael Mengel, Dagmar Hartung, Frank Wacker, Song Rong, Katja Hueper
PURPOSE: The purpose was to characterize acute kidney injury (AKI) in C57BL/6 (B6)- and 129/Sv (Sv)-mice by noninvasive measurement of renal perfusion and tissue edema using functional MRI. METHODS: Different severities of AKI were induced in B6- and Sv-mice by renal ischemia reperfusion injury (IRI). Unilateral clamping of the renal pedicle for 35 min (moderate AKI) or 45 min (severe AKI) was done. MRI (7-Tesla) was performed 1, 7 and 28 days after surgery using a flow alternating inversion recovery (FAIR) arterial spin labeling (ASL) sequence...
2017: PloS One
https://www.readbyqxmd.com/read/28277457/advanced-mri-measures-of-cerebral-perfusion-and-their-clinical-applications
#15
Bryan Lanzman, Jeremy J Heit
Cerebral blood flow measurement by magnetic resonance imaging perfusion (MRP) techniques is broadly applied to patients with acute ischemic stroke, vasospasm following aneurysmal subarachnoid hemorrhage, chronic arterial steno-occlusive disease, cervical atherosclerotic disease, and primary brain neoplasms. MRP may be performed using an exogenous tracer, most commonly gadolinium-based intravenous contrast, or an endogenous tracer, such as arterial spin labeling (ASL) or intravoxel incoherent motion (IVIM). Here, we review the technical basis of commonly performed MRP techniques, the interpretation of MRP imaging maps, and how MRP provides valuable clinical information in the triage of patients with cerebral disease...
April 2017: Topics in Magnetic Resonance Imaging: TMRI
https://www.readbyqxmd.com/read/28266894/aspects-based-reperfusion-status-on-arterial-spin-labeling-is-associated-with-clinical-outcome-in-acute-ischemic-stroke-patients
#16
Songlin Yu, Samantha J Ma, David S Liebeskind, Dandan Yu, Ning Li, Xin J Qiao, Xingfeng Shao, Lirong Yan, Bryan Yoo, Fabien Scalzo, Jason D Hinman, Latisha K Sharma, Neal Rao, Reza Jahan, Satoshi Tateshima, Gary R Duckwiler, Jeffrey L Saver, Noriko Salamon, Danny Jj Wang
The purpose of this study was to develop and evaluate a scoring system for assessing reperfusion status based on arterial spin labeled (ASL) perfusion MRI in acute ischemic stroke (AIS) patients receiving thrombolysis and/or endovascular treatment. Pseudo-continuous ASL with background suppressed 3D GRASE was acquired along with DWI in 90 patients within 24 h post-treatment. An automatic reperfusion scoring system (auto-RPS) was devised based on the Alberta Stroke Program Early CT Score (ASPECTS) template, and compared with manual RPS and DWI-ASPECTS...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28253268/multiband-multi-echo-imaging-of-simultaneous-oxygenation-and-flow-timeseries-for-resting-state-connectivity
#17
Alexander D Cohen, Andrew S Nencka, R Marc Lebel, Yang Wang
A novel sequence has been introduced that combines multiband imaging with a multi-echo acquisition for simultaneous high spatial resolution pseudo-continuous arterial spin labeling (ASL) and blood-oxygenation-level dependent (BOLD) echo-planar imaging (MBME ASL/BOLD). Resting-state connectivity in healthy adult subjects was assessed using this sequence. Four echoes were acquired with a multiband acceleration of four, in order to increase spatial resolution, shorten repetition time, and reduce slice-timing effects on the ASL signal...
2017: PloS One
https://www.readbyqxmd.com/read/28249119/enhanced-task-related-brain-activation-and-resting-perfusion-in-healthy-older-adults-after-chronic-blueberry-supplementation
#18
Joanna L Bowtell, Zainie Aboo-Bakkar, Myra Conway, Anna-Lynne R Adlam, Jonathan Fulford
Blueberries are rich in flavonoids, which possess antioxidant and anti-inflammatory properties. High flavonoid intakes attenuate age-related cognitive decline, but data from human intervention studies are sparse. We investigated whether 12 weeks of blueberry concentrate supplementation improved brain perfusion, task-related activation and cognitive function in healthy older adults. Participants were randomised to consume either 30 ml blueberry concentrate providing 387 mg anthocyanidins (5 female, 7 male; age 67...
March 1, 2017: Applied Physiology, Nutrition, and Metabolism, Physiologie Appliquée, Nutrition et Métabolisme
https://www.readbyqxmd.com/read/28195664/an-adaptive-model-for-rapid-and-direct-estimation-of-extravascular-extracellular-space-in-dynamic-contrast-enhanced-mri-studies
#19
Azimeh N V Dehkordi, Alireza Kamali-Asl, James R Ewing, Ning Wen, Indrin J Chetty, Hassan Bagher-Ebadian
Extravascular extracellular space (ve ) is a key parameter to characterize the tissue of cerebral tumors. This study introduces an artificial neural network (ANN) as a fast, direct, and accurate estimator of ve from a time trace of the longitudinal relaxation rate, ΔR1 (R1  = 1/T1 ), in DCE-MRI studies. Using the extended Tofts equation, a set of ΔR1 profiles was simulated in the presence of eight different signal to noise ratios. A set of gain- and noise-insensitive features was generated from the simulated ΔR1 profiles and used as the ANN training set...
May 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28192548/association-of-collateral-blood-vessels-detected-by-arterial-spin-labeling-magnetic-resonance-imaging-with-neurological-outcome-after-ischemic-stroke
#20
Adam de Havenon, David R Haynor, David L Tirschwell, Jennifer J Majersik, Gordon Smith, Wendy Cohen, Jalal B Andre
Importance: Robust collateral blood vessels have been associated with better neurologic outcome following acute ischemic stroke (AIS). The most commonly used methods for identifying collaterals are contrast-based angiographic imaging techniques, which are not possible in all patients after AIS. Objective: To assess the association between the presence of collateral vessels identified using arterial spin labeling (ASL) magnetic resonance imaging, a technique that does not require exogenous administration of contrast, and neurologic outcome in patients after AIS...
April 1, 2017: JAMA Neurology
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