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ASL and MRI

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https://www.readbyqxmd.com/read/28543885/dce-mri-prediction-of-survival-time-for-patients-with-glioblastoma-multiforme-using-an-adaptive-neuro-fuzzy-based-model-and-nested-model-selection-technique
#1
Azimeh N V Dehkordi, Alireza Kamali-Asl, Ning Wen, Tom Mikkelsen, Indrin J Chetty, Hassan Bagher-Ebadian
This pilot study investigates the construction of an Adaptive Neuro-Fuzzy Inference System (ANFIS) for the prediction of the survival time of patients with glioblastoma multiforme (GBM). ANFIS is trained by the pharmacokinetic (PK) parameters estimated by the model selection (MS) technique in dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) data analysis, and patient age. DCE-MRI investigations of 33 treatment-naïve patients with GBM were studied. Using the modified Tofts model and MS technique, the following physiologically nested models were constructed: Model 1, no vascular leakage (normal tissue); Model 2, leakage without efflux; Model 3, leakage with bidirectional exchange (influx and efflux)...
May 25, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28537106/vasoreactivity-in-cadasil-comparison-to-structural-mri-and-neuropsychology
#2
Fiona C Moreton, Breda Cullen, Christian Delles, Celestine Santosh, Rosario L Gonzalez, Krishna Dani, Keith W Muir
Impaired cerebrovascular reactivity precedes histological and clinical evidence of CADASIL in animal models. We aimed to more fully characterise peripheral and cerebral vascular function and reactivity in a cohort of adult CADASIL patients, and explore the associations of these with conventional clinical, imaging and neuropsychological measures. A total of 22 adults with CADASIL gave informed consent to participate in an exploratory study of vascular function in CADASIL. Clinical assessment, comprehensive vascular assessment, MRI and neuropsychological testing were conducted...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28528845/comparison-of-3-and-7-t-asl-techniques-for-concurrent-functional-perfusion-and-bold-studies
#3
Dimo Ivanov, Anna Gardumi, Roy Am Haast, Josef Pfeuffer, Benedikt A Poser, Kâmil Uludağ
Arterial spin labeling (ASL) is the primary non-invasive MRI approach to measure baseline cerebral blood flow (CBF) in healthy subjects and patients. ASL also allows concurrent functional BOLD signal and CBF measurements, but the latter typically suffers from low contrast-to-noise (CNR) ratio. Ultra-high-field imaging significantly boosts BOLD signal CNR. However, it is contested whether also CBF CNR benefits from increasing magnetic field strength, especially given that technical challenges related to field inhomogeneities and power deposition constraints exist...
May 18, 2017: NeuroImage
https://www.readbyqxmd.com/read/28513057/systemic-inflammation-and-alterations-to-cerebral-blood-flow-in-obstructive-sleep-apnea
#4
Hsiu-Ling Chen, Hsin-Ching Lin, Cheng-Hsien Lu, Pei-Chin Chen, Chih-Cheng Huang, Kun-Hsien Chou, Mao-Chang Su, Michael Friedman, Yi-Wen Chen, Wei-Che Lin
Systemic inflammation and alterations to regional cerebral blood flow (CBF) have been reported previously in obstructive sleep apnea (OSA). This study utilized arterial spin labelling (ASL) perfusion magnetic resonance imaging (MRI) to evaluate CBF in OSA patients and determine its relationship with systemic inflammation. Twenty male patients with moderate and severe OSA [apnea-hypopnea index (AHI) >15] and 16 healthy male volunteers (AHI <5) were recruited. Early- or late-phase changes in leucocyte apoptosis and its subsets were determined by flow cytometry...
May 17, 2017: Journal of Sleep Research
https://www.readbyqxmd.com/read/28507896/intraoperative-resection-control-using-arterial-spin-labeling-proof-of-concept-reproducibility-of-data-and-initial-results
#5
Thomas Lindner, Hajrullah Ahmeti, Isabel Lübbing, Michael Helle, Olav Jansen, Michael Synowitz, Stephan Ulmer
OBJECTIVES: Intraoperative magnetic resonance imaging is a unique tool for visualizing structures during resection and/or for updating any kind of neuronavigation that might be hampered as a result of brain shift during surgery. Advanced MRI techniques such as perfusion-weighted imaging have already proven to be important in the initial diagnosis preoperatively, but can also help to differentiate between tumor and surgically induced changes intraoperatively. Commonly used methods to visualize brain perfusion include contrast agent administration and are therefore somewhat limited...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28506213/voxel-wise-correlations-between-cognition-and-cerebral-blood-flow-using-arterial-spin-labeled-perfusion-mri-in-patients-with-alzheimer-s-disease-a-cross-sectional-study
#6
Tomohiro Kaneta, Omi Katsuse, Takamasa Hirano, Matsuyoshi Ogawa, Ayako Shihikura-Hino, Keisuke Yoshida, Toshinari Odawara, Yoshio Hirayasu, Tomio Inoue
BACKGROUND: To analyze voxel-wise correlation between cerebral blood flow (CBF) measured using ASL-MRI and cognition in patients with Alzheimer's disease (AD). METHODS: Forty-one patients diagnosed with AD or mild cognitive impairment due to AD were recruited for this study. CBF images were obtained using ASL-MRI (n = 41) with a post-labeling delay (PLD) of 1.5 and 2.5 s (PLD1.5 and PLD2.5, respectively) using a 3 T scanner, in addition to brain perfusion SPECT with N-isopropyl-4-[I-123]iodoamphetamine (n = 28)...
May 15, 2017: BMC Neurology
https://www.readbyqxmd.com/read/28480534/comparison-of-perfusion-signal-acquired-by-arterial-spin-labeling-prepared-intravoxel-incoherent-motion-ivim-mri-and-conventional-ivim-mri-to-unravel-the-origin-of-the-ivim-signal
#7
Xingxing Zhang, Carson Ingo, Wouter M Teeuwisse, Zhensen Chen, Matthias J P van Osch
PURPOSE: Applications of intravoxel incoherent motion (IVIM) imaging in the brain are scarce, whereas it has been successfully applied in other organs with promising results. To better understand the cerebral IVIM signal, the diffusion properties of the arterial blood flow within different parts of the cerebral vascular tree (i.e., different generations of the branching pattern) were isolated and measured by employing an arterial spin labeling (ASL) preparation module before an IVIM readout...
May 7, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28431859/mri-based-quantification-of-renal-perfusion-in-mice-improving-sensitivity-and-stability-in-fair-asl
#8
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
#9
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
#10
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
#11
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
#12
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
#13
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
#14
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
#15
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
#16
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
#17
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
#18
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
#19
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
#20
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 18, 2017: NeuroImage
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