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Arterial spin labelling

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https://www.readbyqxmd.com/read/29453753/pediatric-astrocytic-tumor-grading-comparison-between-arterial-spin-labeling-and-dynamic-susceptibility-contrast-mri-perfusion
#1
Giovanni Morana, Domenico Tortora, Serena Staglianò, Paolo Nozza, Samantha Mascelli, Mariasavina Severino, Gianluca Piatelli, Alessandro Consales, Maarten Lequin, Maria Luisa Garrè, Andrea Rossi
PURPOSE: The aim of this study was to compare arterial spin labeling (ASL) and dynamic susceptibility contrast (DSC) MRI perfusion with respect to diagnostic performance in tumor grading in pediatric patients with low- and high-grade astrocytic tumors (AT). METHODS: We retrospectively analyzed 37 children with histologically proven treatment naive low- and high-grade AT who underwent concomitant pre-operative ASL and DSC MRI perfusion. Studies were performed on a 1...
February 16, 2018: Neuroradiology
https://www.readbyqxmd.com/read/29452984/quantitative-cerebrovascular-pathology-in-a-community-based-cohort-of-older-adults
#2
Swati Rane, Natalie Koh, Peter Boord, Tara Madhyastha, Mary K Askren, Suman Jayadev, Brenna Cholerton, Eric Larson, Thomas J Grabowski
Cerebrovascular disease, especially small vessel pathology, is the leading comorbidity in degenerative disorders. We applied arterial spin labeling and cerebrovascular reserve (CVR) imaging to quantify small vessel disease and study its effect on cognitive symptoms in nondemented older adults from a community-based cohort. We evaluated baseline cerebral blood flow (CBF) using arterial spin labeling and percent signal change as a marker of CVR using blood-oxygen level-dependent imaging following a breath-hold stimulus...
January 31, 2018: Neurobiology of Aging
https://www.readbyqxmd.com/read/29450932/cardiorespiratory-noise-correction-improves-the-asl-signal
#3
Mahlega S Hassanpour, Qingfei Luo, W Kyle Simmons, Justin S Feinstein, Martin P Paulus, Wen-Ming Luh, Jerzy Bodurka, Sahib S Khalsa
Cardiorespiratory fluctuations such as changes in heart rate or respiration volume influence the temporal dynamics of cerebral blood flow (CBF) measurements during arterial spin labeling (ASL) fMRI. This "physiological noise" can confound estimates of resting state network activity, and it may lower the signal-to-noise ratio of ASL during task-related experiments. In this study we examined several methods for minimizing the contributions of both synchronized and non-synchronized physiological noise in ASL measures of CBF, by combining the RETROICOR approach with different linear deconvolution models...
February 15, 2018: Human Brain Mapping
https://www.readbyqxmd.com/read/29447849/three-dimensional-arterial-spin-labeling-imaging-with-a-dante-preparation-pulse
#4
Tsuyoshi Matsuda, Hirohiko Kimura, Hiroyuki Kabasawa, Masayuki Kanamoto
On arterial spin-labeled (ASL) images, areas of bright intravascular signal will appear when the post labeling delay time is shorter than arterial transit time. Vascular suppression (VS) schemes reduce artefactual bright signal by dephasing intravascular labeled spins. However, existing VS methods, such as Motion-Sensitized Driven-Equilibrium (MSDE), decrease the uniformity of the signal intensity distribution and extend the echo time. The purpose of this study is to compare VS using a Delays Alternating with Nutation for Tailored Excitation (DANTE) preparation pulse, with MSDE for ASL imaging on a flow phantom and volunteer data...
February 12, 2018: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/29440719/prefrontal-gaba-levels-hippocampal-resting-perfusion-and-the-risk-of-psychosis
#5
Gemma Modinos, Fatma Şimşek, Matilda Azis, Matthijs Bossong, Ilaria Bonoldi, Carly Samson, Beverly Quinn, Jesus Perez, Matthew R Broome, Fernando Zelaya, David J Lythgoe, Oliver D Howes, James M Stone, Anthony A Grace, Paul Allen, Philip McGuire
Preclinical models propose that the onset of psychosis is associated with hippocampal hyperactivity, thought to be driven by cortical GABAergic interneuron dysfunction and disinhibition of pyramidal neurons. Recent neuroimaging studies suggest that resting hippocampal perfusion is increased in subjects at ultra-high risk (UHR) for psychosis, but how this may be related to GABA concentrations is unknown. The present study used a multimodal neuroimaging approach to address this issue in UHR subjects. Proton magnetic resonance spectroscopy and pulsed-continuous arterial spin labeling imaging were acquired to investigate the relationship between medial prefrontal (MPFC) GABA+ levels (including some contribution from macromolecules) and hippocampal regional cerebral blood flow (rCBF) in 36 individuals at UHR of psychosis, based on preclinical evidence that MPFC dysfunction is involved in hippocampal hyperactivity...
January 30, 2018: Neuropsychopharmacology: Official Publication of the American College of Neuropsychopharmacology
https://www.readbyqxmd.com/read/29436733/placental-perfusion-imaging-using-velocity-selective-arterial-spin-labeling
#6
Zungho Zun, Catherine Limperopoulos
PURPOSE: The placenta remains the least understood human organ, in large part because of the lack of noninvasive tools currently available to examine placental function in vivo. This study investigates the feasibility of using velocity-selective arterial spin labeling (VSASL) to assess placental perfusion. METHODS: In placental perfusion imaging, VSASL was compared with pseudocontinuous ASL (PCASL), which is currently the standard technique in brain arterial spin labeling (ASL)...
February 13, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29434092/water-diffusion-in-the-brain-of-chronic-hypoperfusion-model-mice-a-study-considering-the-effect-of-blood-flow
#7
Takuya Urushihata, Hiroyuki Takuwa, Chie Seki, Yasuhiko Tachibana, Manami Takahashi, Jeff Kershaw, Yuhei Takado, Ichio Aoki, Makoto Higuchi, Hiroshi Ito, Takayuki Obata
PURPOSE: Chronic cerebral hypoperfusion model mice were created by unilateral common carotid artery occlusion (UCCAO) surgery, which does not cause cerebral infarction, but which does cause long-term reduction in cerebral blood flow (CBF) to the occluded side. Cognitive dysfunction in this mouse model has been demonstrated in behavioral experiments, but neuron density change was not found in a previous positron emission tomography (PET) study. As a next step, in this study we investigated the injury of neuronal fibers in chronic cerebral hypoperfusion model mice using diffusion tensor imaging (DTI)...
February 13, 2018: Magnetic Resonance in Medical Sciences: MRMS
https://www.readbyqxmd.com/read/29431005/reduced-blood-oxygenation-level-dependent-connectivity-is-related-to-hypoperfusion-in-alzheimer-s-disease
#8
Jens Göttler, Christine Preibisch, Isabelle Riederer, Lorenzo Pasquini, Panagiotis Alexopoulos, Karl Peter Bohn, Igor Yakushev, Ebba Beller, Stephan Kaczmarz, Claus Zimmer, Timo Grimmer, Alexander Drzezga, Christian Sorg
Functional connectivity of blood oxygenation level dependent signal fluctuations (BOLD-FC) is decreased in Alzheimer's disease (AD), and suggested to reflect reduced coherence in neural population activity; however, as both neuronal and vascular-hemodynamic processes underlie BOLD signals, impaired perfusion might also contribute to reduced BOLD-FC; 42 AD patients and 27 controls underwent simultaneous PET/MR imaging. Resting-state functional MRI assessed BOLD co-activity to quantify BOLD-FC, pulsed arterial spin labeling (pASL) assessed cerebral blood flow (CBF) as proxy for vascular hemodynamics, and 18F-fluorodeoxyglucose PET assessed glucose metabolism (GluMet) to index neuronal activity...
January 1, 2018: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/29427325/controlling-t2-blurring-in-3d-rare-arterial-spin-labeling-acquisition-through-optimal-combination-of-variable-flip-angles-and-k-space-filtering
#9
Li Zhao, Ching-Di Chang, David C Alsop
PURPOSE: To improve the SNR efficiency and reduce the T2 blurring of 3D rapid acquisition with relaxation enhancement stack-of-spiral arterial spin labeling imaging by using variable refocusing flip angles and k-space filtering. METHODS: An algorithm for determining the optimal combination of variable flip angles and filtering correction is proposed. The flip angles are designed using extended phase graph physical simulations in an analytical and global optimization framework, with an optional constraint on deposited power...
February 9, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29422857/application-of-arterial-spin-labelling-in-detecting-retinal-ischemia
#10
Ehsan Vaghefi, Kevin Kauv, Wilson Pan, David Squirrell
Purpose: Here, we have tried to quantify the chorioretinal blood perfusion in patients who are clinically identified to be suffering from retinal ischemia using arterial spin labelling (ASL) MRI. Method: Four participants, diagnosed with retinal ischemia based on their structural OCT and angiography test, were then scanned using anatomical MRI as well as ASL. We optimized MR parameters to maximize resolution and target fixation, blinking, and breathing ques to minimize motion artifacts...
September 2017: Case Reports in Ophthalmology
https://www.readbyqxmd.com/read/29416525/patient-specific-alterations-in-co2-cerebrovascular-responsiveness-in-acute-and-sub-acute-sports-related-concussion
#11
W Alan C Mutch, Michael J Ellis, Lawrence N Ryner, Patrick J McDonald, Marc P Morissette, Philip Pries, Marco Essig, David J Mikulis, James Duffin, Joseph A Fisher
Background: Preliminary studies suggest that sports-related concussion (SRC) is associated with alterations in cerebral blood flow (CBF) regulation. Here, we use advanced magnetic resonance imaging (MRI) techniques to measure CBF and cerebrovascular responsiveness (CVR) in individual SRC patients and healthy control subjects. Methods: 15 SRC patients (mean age = 16.3, range 14-20 years) and 27 healthy control subjects (mean age = 17.6, range 13-21 years) underwent anatomical MRI, pseudo-continuous arterial spin labeling (pCASL) MRI and model-based prospective end-tidal targeting (MPET) of CO2 during blood oxygenation level-dependent (BOLD) MRI...
2018: Frontiers in Neurology
https://www.readbyqxmd.com/read/29398151/differentiation-between-radiation-induced-brain-injury-and-glioma-recurrence-using-3d-pcasl-and-dynamic-susceptibility-contrast-enhanced-perfusion-weighted-imaging
#12
Yu-Lin Wang, Si Chen, Hua-Feng Xiao, Ying Li, Yan Wang, Gang Liu, Xin Lou, Lin Ma
PURPOSE: This study was performed to validate the efficacy of three-dimensional pseudocontinuous arterial spin labeling (pCASL) compared with dynamic susceptibility contrast-enhanced perfusion-weighted imaging (DSC-PWI) in distinguishing radiation-induced brain injury from glioma recurrence in patients with glioma. METHODS: Both 3D pCASL and DSC-PWI were performed using a 3.0 Tesla scanner in 69 patients with previously resected and irradiated glioma who displayed newly developed abnormal contrast-enhanced lesions...
February 1, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29391824/altered-perfusion-of-the-sensorimotor-cortex-in-patients-with-cervical-spondylotic-myelopathy-an-arterial-spin-labeling-study
#13
Fuqing Zhou, Muhua Huang, Lin Wu, Yongming Tan, Jianqiang Guo, Yong Zhang, Laichang He, Honghan Gong
Objective: Advanced magnetic resonance imaging studies have shown functional plasticity or reorganization and metabolite alterations of N-acetyl aspartate in the sensorimotor cortex (SMC), a hallmark region and key brain network, in patients with cervical spondylotic myelopathy (CSM). However, the nature of perfusion in the SMC and the relationship between regional cerebral blood flow (CBF), motor function scores, and structural damage of the cervical cord in patients with CSM are not fully understood...
2018: Journal of Pain Research
https://www.readbyqxmd.com/read/29390403/tumor-recurrence-versus-treatment-effects-in-glioma-a-comparative-study-of-three-dimensional-pseudo-continuous-arterial-spin-labeling-and-dynamic-susceptibility-contrast-imaging
#14
Qian Xu, Qi Liu, Haitao Ge, Xinting Ge, Jiangfen Wu, Jianxun Qu, Kai Xu
BACKGROUND: Gliomas constitute over 90% of primary brain tumors. Accurate identification of glioma recurrence and treatment effects is important, as it can help determine whether to continue with standard adjuvant chemotherapy or to switch to a second-line therapy for recurrence. Our purpose is to compare three dimensional pseudo-continuous arterial spin labeling (3D-pcASL) technique and dynamic susceptibility contrast perfusion magnetic resonance imaging (DSC-MRI) for differentiation tumor recurrence from treatment-related effects in gliomas...
December 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/29389985/multiband-multi-echo-simultaneous-asl-bold-for-task-induced-functional-mri
#15
Alexander D Cohen, Andrew S Nencka, Yang Wang
Typical simultaneous blood oxygenation-level dependent (BOLD) and arterial spin labeling (ASL) sequences acquire two echoes, one perfusion-sensitive and one BOLD-sensitive. However, for ASL, spatial resolution and brain coverage are limited due to the T1 decay of the labeled blood. This study applies a sequence combining a multiband acquisition with four echoes for simultaneous BOLD and pseudo-continuous ASL (pCASL) echo planar imaging (MBME ASL/BOLD) for block-design task-fMRI. A multiband acceleration of four was employed to increase brain coverage and reduce slice-timing effects on the ASL signal...
2018: PloS One
https://www.readbyqxmd.com/read/29370984/photon-vs-proton-radiochemotherapy-effects-on-brain-tissue-volume-and-perfusion
#16
Jan Petr, Ivan Platzek, Frank Hofheinz, Henri J M M Mutsaerts, Iris Asllani, Matthias J P van Osch, Annekatrin Seidlitz, Pawel Krukowski, Andreas Gommlich, Bettina Beuthien-Baumann, Christina Jentsch, Jens Maus, Esther G C Troost, Michael Baumann, Mechthild Krause, Jörg van den Hoff
BACKGROUND AND PURPOSE: To compare the structural and hemodynamic changes of healthy brain tissue in the cerebral hemisphere contralateral to the tumor following photon and proton radiochemotherapy. MATERIALS AND METHODS: Sixty-seven patients (54.9 ±14.0 years) diagnosed with glioblastoma undergoing adjuvant photon (n = 47) or proton (n = 19) radiochemotherapy with temozolomide after tumor resection underwent T1-weighted and arterial spin labeling MRI...
January 19, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
https://www.readbyqxmd.com/read/29369424/non-contrast-enhanced-4d-intracranial-mr-angiography-based-on-pseudo-continuous-arterial-spin-labeling-with-the-keyhole-and-view-sharing-technique
#17
Makoto Obara, Osamu Togao, Gabriele M Beck, Shuhei Shibukawa, Tomoyuki Okuaki, Masami Yoneyama, Masanobu Nakamura, Hiroshi Honda, Marc Van Cauteren
PURPOSE: 4D dynamic MR angiography (4D-MRA) using pseudo-continuous arterial spin labeling (pCASL), combined with Keyhole and View-sharing (4D-PACK) for scan acceleration, is introduced. Its validity for arterial inflow dynamics visualization was investigated through comparison with 4D-pCASL and contrast inherent inflow enhanced multiphase angiography (CINEMA). METHODS: Six healthy volunteers were included in the study. The arterial transit time (ATT) in 4D-PACK was measured at multiple regions in middle cerebral artery (MCA), and Pearson's correlation coefficient with ATT in 4D-pCASL was calculated...
January 25, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29369422/cardiac-triggered-pseudo-continuous-arterial-spin-labeling-a-cost-effective-scheme-to-further-enhance-the-reliability-of-arterial-spin-labeling-mri
#18
Yang Li, Deng Mao, Zhiqiang Li, Michael Schär, Jay J Pillai, James G Pipe, Hanzhang Lu
PURPOSE: Arterial-spin-labeling (ASL) magnetic resonance imaging (MRI) is intrinsically a low signal-to-noise ratio (SNR) technique. This study aims to enhance its sensitivity by quantifying physiological noise attributed to cardiac pulsation and devising an improved sequence, cardiac-triggered ASL, to minimize this noise. METHODS: A total of 16 healthy subjects were studied on a 3 Tesla MRI system. The influence of cardiac pulsation on pseudo-continuous ASL (pCASL) signal was first investigated by performing a regular pCASL sequence while the cardiac phase of the image acquisition was recorded by a pulse oximeter...
January 25, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29367598/cerebral-perfusion-insufficiency-and-relationships-with-cognitive-deficits-in-alzheimer-s-disease-a-multiparametric-neuroimaging-study
#19
Chi-Wei Huang, Shih-Wei Hsu, Ya-Ting Chang, Shu-Hua Huang, Yung-Cheng Huang, Chen-Chang Lee, Wen-Neng Chang, Chun-Chung Lui, Na-Ching Chen, Chiung-Chih Chang
Micro- or macro-circulatory insufficiency has a negative impact in patients with Alzheimer's disease (AD). This study used arterial spin-labeled magnetic resonance imaging (ASL-MRI) and ethylcysteinate dimer single-photon emission computed tomography (ECD-SPECT) in 50 patients with AD and 30 age-matched controls to investigate how hypoperfusion patterns were associated with gray matter atrophy and clinical data. All participants completed 3DT1-MRI, ECD-SPECT and ASL-MRI examinations. Medial temporal cortex (MTC) volumes were correlated with regional signals showing significantly lower relative cerebral blood flow (rCBF) in ASL-MRI or perfusion index (PI) in ECD-SPECT...
January 24, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29355449/cigarette-smoking-and-cerebral-blood-flow-in-a-cohort-of-middle-aged-adults
#20
Martine Elbejjani, Reto Auer, Sudipto Duloi, David R Jacobs, Thaddeus Haight, David C Goff, John A Detre, Christos Davatzikos, R Nick Bryan, Lenore J Launer
Cigarette smoking is often associated with dementia. This association is thought to be mediated by hypoperfusion; however, how smoking behavior relates to cerebral blood flow (CBF) remains unclear. Using data from the Coronary Artery Risk Development in Young Adults (CARDIA) cohort (mean age = 50; n = 522), we examined the association between smoking behavior (status, cumulative pack-years, age at smoking initiation, and years since cessation) and CBF (arterial spin labeling) in brain lobes and regions linked to dementia...
January 1, 2018: Journal of Cerebral Blood Flow and Metabolism
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