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ASL and MRI

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https://www.readbyqxmd.com/read/27913820/cerebral-blood-flow-transit-time-and-apparent-diffusion-coefficient-in-moyamoya-disease-before-and-after-acetazolamide
#1
Christian Federau, Soren Christensen, Zungho Zun, Sun-Won Park, Wendy Ni, Michael Moseley, Greg Zaharchuk
INTRODUCTION: The goal of this study was to assess the changes in arterial spin labeling (ASL) cerebral blood flow (CBF) and arterial transit time (ATT), and in apparent diffusion coefficient (ADC), before and after an acetazolamide challenge in moyamoya patients, as function of arterial stenosis severity. METHODS: Pre-operative patients diagnosed with moyamoya disease who could undergo MRI at 3.0T were recruited for this study. A multi-delay pseudo-continuous ASL and a diffusion-weighted sequence were acquired before and 15 min after acetazolamide injection...
December 2, 2016: Neuroradiology
https://www.readbyqxmd.com/read/27911758/multimodal-imaging-for-dreadd-expressing-neurons-in-living-brain-and-their-application-to-implantation-of-ipsc-derived-neural-progenitors
#2
Bin Ji, Hiroyuki Kaneko, Takafumi Minamimoto, Haruhisa Inoue, Hiroki Takeuchi, Katsushi Kumata, Ming-Rong Zhang, Ichio Aoki, Chie Seki, Maiko Ono, Masaki Tokunaga, Satoshi Tsukamoto, Koji Tanabe, Ryong-Moon Shin, Takeharu Minamihisamatsu, Seiji Kito, Barry J Richmond, Tetsuya Suhara, Makoto Higuchi
: Chemogenetic manipulation of neuronal activities has been enabled by a designer receptor (designer receptor exclusively activated by designer drugs, DREADD) that is activated exclusively by clozapine-N-oxide (CNO). Here, we applied CNO as a functional reporter probe to positron emission tomography (PET) of DREADD in living brains. Mutant human M4 DREADD (hM4Di) expressed in transgenic (Tg) mouse neurons was visualized by PET with microdose [(11)C]CNO. Deactivation of DREADD-expressing neurons in these mice by nonradioactive CNO at a pharmacological dose could also be captured by arterial spin labeling MRI (ASL-MRI)...
November 9, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/27908711/cerebral-blood-flow-measured-by-arterial-spin-labeling-mri-at-resting-state-in-normal-aging-and-alzheimer-s-disease
#3
REVIEW
Nan Zhang, Marc L Gordon, Terry E Goldberg
Arterial spin labeling (ASL) magnetic resonance imaging uses arterial blood water as an endogenous tracer to measure cerebral blood flow (CBF). In this review, based on ASL studies in the resting state, we discuss state-of-the-art technical and data processing improvements in ASL, and ASL CBF changes in normal aging, mild cognitive impairment (MCI), Alzheimer's disease (AD), and other types of dementia. We propose that vascular and AD risk factors should be considered when evaluating CBF changes in aging, and that other validated biomarkers should be used as inclusion criteria or covariates when evaluating CBF changes in MCI and AD...
November 28, 2016: Neuroscience and Biobehavioral Reviews
https://www.readbyqxmd.com/read/27898185/perfusion-has-no-effect-on-the-in-vivo-cest-effect-from-cr-crcest-in-skeletal-muscle
#4
Feliks Kogan, Randall B Stafford, Erin K Englund, Garry E Gold, Hari Hariharan, John A Detre, Ravinder Reddy
Creatine, a key component of muscle energy metabolism, exhibits a chemical exchange saturation transfer (CEST) effect between its amine group and bulk water, which has been exploited to spatially and temporally map creatine changes in skeletal muscle before and after exercise. In addition, exercise leads to an increase in muscle perfusion. In this work, we determined the effects of perfused blood on the CEST effects from creatine in skeletal muscle. Experiments were performed on healthy human subjects (n = 5) on a whole-body Siemens 7T magnetic resonance imaging (MRI) scanner with a 28-channel radiofrequency (RF) coil...
November 29, 2016: NMR in Biomedicine
https://www.readbyqxmd.com/read/27876537/artificial-neural-networks-approach-to-pharmacokinetic-model-selection-in-dce-mri-studies
#5
Mohammad-Reza Mohammadian-Behbahani, Ali-Reza Kamali-Asl
PURPOSE: In pharmacokinetic analysis of Dynamic Contrast Enhanced MRI data, a descriptive physiological model should be selected properly out of a set of candidate models. Classical techniques suggested for this purpose suffer from issues like computation time and general fitting problems. This article proposes an approach based on Artificial Neural Networks (ANNs) for solving these problems. METHODS: A set of three physiologically and mathematically nested models generated from the Tofts model were assumed: Model I, II and III...
November 19, 2016: Physica Medica: PM
https://www.readbyqxmd.com/read/27867814/the-assessment-of-myometrium-perfusion-in-patients-with-uterine-fibroid-by-arterial-spin-labeling-mri
#6
Nozomi Takahashi, Osamu Yoshino, Osamu Hiraike, Eriko Maeda, Masanobu Nakamura, Masaaki Hori, Miyuki Harada, Kaori Koga, Shigeru Saito, Tomoyuki Fujii, Yutaka Osuga
BACKGROUND: It has been suggested that an inadequate blood supply caused by uterine fibroids may lead to decreasing fertility. Therefore, a quantitative evaluation of blood flow in the uterus might be a good tool for infertility treatments. For the first step, the ability to perform arterial spin labeling (ASL)-MRI in pelvic organs was examined by measuring blood flow in the uterine muscle layer. RESULTS: Three normal volunteer women, seven patients with one uterine fibroid and four patients treated with GnRH analogue for uterine fibroids, were enrolled in this study...
2016: SpringerPlus
https://www.readbyqxmd.com/read/27867170/evaluation-of-appropriate-readout-sequence-for-renal-mri-perfusion-using-astar-asl-technique
#7
Kyoko Takakura, Aki Kido, Koji Fujimoto, Kayo Kiguchi, Yasutaka Fushimi, Naotaka Sakashita, Tokunori Kimura, Kaori Togashi
The aim of this study was to compare true-steady state free precession (True-SSFP) with fast field echo (FFE) as readout imaging sequences for renal arterial spin labeling (ASL), and to optimize the imaging condition. Renal ASL perfusion images were acquired using signal targeting with alternated radio frequency using asymmetric inversion slab (ASTAR) technique with respiratory triggering at 3T MRI system, using either 3D True-SSFP or FFE as the readout sequence. Inversion time (TI) varied from 800 to 2400 ms...
2016: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/27864008/renal-plasma-flow-rpf-measured-with-multiple-inversion-time-arterial-spin-labeling-asl-and-tracer-kinetic-analysis-validation-against-a-dynamic-contrast-enhancement-method
#8
Christopher C Conlin, Niels Oesingmann, Bradley Bolster, Yufeng Huang, Vivian S Lee, Jeff L Zhang
PURPOSE: To propose and validate a method for accurately quantifying renal plasma flow (RPF) with arterial spin labeling (ASL). MATERIALS AND METHODS: The proposed method employs a tracer-kinetic approach and derives perfusion from the slope of the ASL difference signal sampled at multiple inversion-times (TIs). To validate the method's accuracy, we performed a HIPAA-compliant and IRB-approved study with 15 subjects (9 male, 6 female; age range 24-73) to compare RPF estimates obtained from ASL to those from a more established dynamic contrast-enhanced (DCE) MRI method...
November 15, 2016: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/27858468/a-qualitative-comparison-of-arterial-spin-labelling-and-dynamic-susceptibility-contrast-mri-in-52-children-with-a-range-of-neurological-conditions
#9
Paul A Armitage, Nicholas Skipper, Daniel J A Connolly, Paul D Griffiths
OBJECTIVE: To assess the usefulness of Arterial Spin Labelling (ASL) compared with Dynamic Susceptibility Contrast (DSC) perfusion MRI for typical paediatric neuroimaging applications at 1.5 Tesla. METHODS: 52 children (age: 4 months - 17 years) with a variety of neurological disorders were scanned using 3D ASL and Echo Planar Imaging DSC sequences. All images were reviewed by an experienced neuroradiologist, image quality recorded as 'good', 'acceptable', or 'poor' and diagnostic value noted as being 'greater', 'similar' or 'less' for ASL when compared to DSC...
November 18, 2016: British Journal of Radiology
https://www.readbyqxmd.com/read/27842984/usefulness-of-3-tesla-magnetic-resonance-arterial-spin-labeled-imaging-for-diagnosis-of-cranial-dural-arteriovenous-fistula
#10
Nobuaki Yamamoto, Junichiro Satomi, Yuki Yamamoto, Yuishin Izumi, Shinji Nagahiro, Ryuji Kaji
BACKGROUND AND PURPOSE: Conventional digital subtraction angiography (DSA) has been a useful tool for the diagnosis of cranial dural arteriovenous fistula (cDAVF). In most patients with cDAVF, blood flow through the arteriovenous shunt was pooled at diseased veins and/or sinuses. Therefore, we speculated that pooled blood at diseased veins in patients with cDAVF could be detected on arterial spin-labeled imaging (ASL). The purpose of the present study was to investigate the usefulness of ASL to detect cDAVF...
November 10, 2016: Journal of the Neurological Sciences
https://www.readbyqxmd.com/read/27822669/asl-and-susceptibility-weighted-imaging-contribution-to-the-management-of-acute-ischaemic-stroke
#11
REVIEW
Sébastien Verclytte, Olivier Fisch, Lucie Colas, Olivier Vanaerde, Manuel Toledano, Jean-François Budzik
: Magnetic resonance imaging (MRI) plays a central role in the early diagnosis of cerebral vascular events. Today, MRI is used not only for the detection of acute ischaemic lesions, but also to fine tune the diagnosis and improve patient selection for early therapeutic decision-making. In this perspective, new tools such as arterial spin labelling (ASL) and susceptibility-weighted imaging (SWI) sequences have been developed. These MRI sequences enable noninvasive assessment of brain damage, providing important diagnostic and prognostic information: evaluation of cerebral parenchymal perfusion; detection and aetiological assessment of thrombi; ruling out differential diagnoses...
November 7, 2016: Insights Into Imaging
https://www.readbyqxmd.com/read/27813164/3d-accelerated-stack-of-spirals-acquisitions-and-reconstruction-of-arterial-spin-labeling-mri
#12
Yulin V Chang, Marta Vidorreta, Ze Wang, John A Detre
PURPOSE: The goal of this study was to develop a 3D acceleration and reconstruction method to improve image quality and resolution of background-suppressed arterial spin-labeled perfusion MRI. METHODS: Accelerated acquisition was implemented in all three k-space dimensions in a stack-of-spirals readout using variable density spirals and partition undersampling. A single 3D self-consistent parallel imaging (SPIRiT) kernel was calibrated and iteratively applied to reconstruct each imaging volume...
November 3, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27807911/effects-of-reduced-oxygen-availability-on-the-vascular-response-and-oxygen-consumption-of-the-activated-human-visual-cortex
#13
Felipe Rodrigues Barreto, Silvia Mangia, Carlos Ernesto Garrido Salmon
PURPOSE: To identify the impact of reduced oxygen availability on the evoked vascular response upon visual stimulation in the healthy human brain by magnetic resonance imaging (MRI). MATERIALS AND METHODS: Functional MRI techniques based on arterial spin labeling (ASL), blood oxygenation level-dependent (BOLD), and vascular space occupancy (VASO)-dependent contrasts were utilized to quantify the BOLD signal, cerebral blood flow (CBF), and volume (CBV) from nine subjects at 3T (7M/2F, 27...
November 3, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27807678/both-3-t-dgemric-and-acetabular-femoral-t2-difference-may-detect-cartilage-damage-at-the-chondrolabral-junction
#14
Tobias Hesper, Evgeny Bulat, Sarah Bixby, Alireza Akhondi-Asl, Onur Afacan, Patricia Miller, Garrett Bowen, Simon Warfield, Young-Jo Kim
BACKGROUND: In addition to case reports of gadolinium-related toxicities, there are increasing theoretical concerns about the use of gadolinium for MR imaging. As a result, there is increasing interest in noncontrast imaging techniques for biochemical cartilage assessment. Among them, T2 mapping holds promise because of its simplicity, but its biophysical interpretation has been controversial. QUESTIONS/PURPOSES: We sought to determine whether (1) 3-T delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) and T2 mapping are both capable of detecting cartilage damage at the chondrolabral junction in patients with femoroacetabular impingement (FAI); and (2) whether there is a correlation between these two techniques for acetabular and femoral head cartilage assessment...
November 2, 2016: Clinical Orthopaedics and related Research
https://www.readbyqxmd.com/read/27760424/renal-arterial-spin-labeling-magnetic-resonance-imaging
#15
Anton S Becker, Cristina Rossi
Arterial spin labeling (ASL) MRI allows the quantification of tissue perfusion without administration of exogenous contrast agents. Patients with reduced renal function or other contraindications to Gadolinium-based contrast media may benefit from the non-invasive monitoring of tissue microcirculation. So far, only few studies have investigated the sensitivity, the specificity and the reliability of the ASL techniques for the assessment of renal perfusion. Moreover, only little is known about the interplay between ASL markers of perfusion and functional renal filtration parameters...
October 20, 2016: Nephron
https://www.readbyqxmd.com/read/27752510/diagnostic-utility-of-asl-mri-and-fdg-pet-in-the-behavioral-variant-of-ftd-and-ad
#16
Duygu Tosun, Norbert Schuff, Gil D Rabinovici, Nagehan Ayakta, Bruce L Miller, William Jagust, Joel Kramer, Michael M Weiner, Howard J Rosen
OBJECTIVE: To compare the values of arterial spin-labeled (ASL) MRI and fluorodeoxyglucose (FDG) PET in the diagnosis of behavioral variant of frontotemporal dementia (bvFTD) and Alzheimer's disease (AD). METHODS: Partial least squares logistic regression was used to identify voxels with diagnostic value in cerebral blood flow (CBF) and cerebral metabolic rate of glucose (CMRgl) maps from patients with bvFTD (n = 32) and AD (n = 28), who were compared with each other and with cognitively normal controls (CN, n = 15)...
October 2016: Annals of Clinical and Translational Neurology
https://www.readbyqxmd.com/read/27717156/combining-arterial-spin-labeling-with-functional-magnetic-resonance-imaging-measurement-for-characterizing-patients-with-minimal-hepatic-encephalopathy
#17
Ying Li, Huaijun Liu, Jiping Yang, Xin Tian, Haiqing Yang, Zuojun Geng
AIM: Our objective is to explore key changes in brain functions in relation to minimal hepatic encephalopathy (MHE). We incorporated both resting-state functional magnetic resonance imaging (fMRI) and arterial spin labeling (ASL) to enhance the detection of MHE. METHODS: We undertook fMRI scanning for 56 MHE patients and 66 healthy controls. Region functional connectivity was carried out to assess the connectivity status between pairs of regions among 90 brain regions...
October 7, 2016: Hepatology Research: the Official Journal of the Japan Society of Hepatology
https://www.readbyqxmd.com/read/27714551/cerebral-perfusion-alterations-in-type-2-diabetes-and-its-relation-to-insulin-resistance-and-cognitive-dysfunction
#18
Ying Cui, Xia Liang, Hong Gu, Yuzheng Hu, Zhen Zhao, Xiang-Yu Yang, Cheng Qian, Yihong Yang, Gao-Jun Teng
To explore the effect of T2DM on cerebral perfusion, and the relationship between cerebral perfusion changes and cognitive impairment as well as diabetic variables, by using a whole-brain arterial spin-labeling (ASL) MRI technique. This prospective study was approved by the local institutional review board and was performed between November 2012 and October 2013. All subjects provided informed consent. Forty T2DM patients and 41 age-, sex- and education-matched healthy controls were included. Cerebral blood flow (CBF) map was obtained by pulsed ASL perfusion imaging at 3 T MRI...
October 6, 2016: Brain Imaging and Behavior
https://www.readbyqxmd.com/read/27688940/cbt-reduces-cbf-cognitive-behavioral-therapy-reduces-cerebral-blood-flow-in-fear-relevant-brain-regions-in-spider-phobia
#19
Leila M Soravia, Ariane Orosz, Simon Schwab, Masahito Nakataki, Roland Wiest, Andrea Federspiel
BACKGROUND: Imaging studies have provided evidence that cognitive-behavioral therapy (CBT) is able to change brain activation in phobic patients in response to threatening stimuli. The changes occurred in both emotion-generating and modulatory regions. In this study, we use a data-driven approach to explore resting state cerebral blood flow (CBF) measured by arterial spin labeling (ASL), before and after CBT. METHODS: Eight female patients with spider phobia were scanned before and 1 month after an exposure-based group therapy for spider phobia...
September 2016: Brain and Behavior
https://www.readbyqxmd.com/read/27649493/regional-reproducibility-of-bold-calibration-parameter-m-oef-and-resting-state-cmro2-measurements-with-quo2-mri
#20
Isabelle Lajoie, Felipe B Tancredi, Richard D Hoge
The current generation of calibrated MRI methods goes beyond simple localization of task-related responses to allow the mapping of resting-state cerebral metabolic rate of oxygen (CMRO2) in micromolar units and estimation of oxygen extraction fraction (OEF). Prior to the adoption of such techniques in neuroscience research applications, knowledge about the precision and accuracy of absolute estimates of CMRO2 and OEF is crucial and remains unexplored to this day. In this study, we addressed the question of methodological precision by assessing the regional inter-subject variance and intra-subject reproducibility of the BOLD calibration parameter M, OEF, O2 delivery and absolute CMRO2 estimates derived from a state-of-the-art calibrated BOLD technique, the QUantitative O2 (QUO2) approach...
2016: PloS One
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