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Peiying Liu, Ying Qi, Zixuan Lin, Qiyong Guo, Xiaoming Wang, Hanzhang Lu
Abnormal cerebral blood flow (CBF) is implicated in several neonatal and infant diseases. However, measurement of CBF in this population remains difficult and has not been used in routine clinical MRI. Arterial spin labeling (ASL) methods suffer from both low SNR and poor quantification when applied to very young children. Furthermore, rapid change in brain physiology in this age range makes it difficult to choose sequence parameters such as labeling pulse flip angle and post labeling delay. Phase-contrast (PC) MRI is another approach to measure flow...
March 10, 2018: NeuroImage
Dong Zhang, Pengcheng Xu, Hongyu Qiao, Xin Liu, Liangping Luo, Wenhua Huang, Heye Zhang, Changzheng Shi
BACKGROUND: Cerebrovascular events are frequently associated with hemodynamic disturbance caused by internal carotid artery (ICA) stenosis. It is challenging to determine the ischemia-related carotid stenosis during the intervention only using digital subtracted angiography (DSA). Inspired by the performance of well-established FFRct technique in hemodynamic assessment of significant coronary stenosis, we introduced a pressure-based carotid arterial functional assessment (CAFA) index generated from computational fluid dynamic (CFD) simulation in DSA data, and investigated its feasibility in the assessment of hemodynamic disturbance preliminarily using pressure-wired measurement and arterial spin labeling (ASL) MRI as references...
March 12, 2018: Biomedical Engineering Online
Lirong Yan, Collin Y Liu, Koon-Pong Wong, Sung-Cheng Huang, Wendy J Mack, Kay Jann, Giovanni Coppola, John M Ringman, Danny J J Wang
Autosomal dominant Alzheimer's disease (ADAD) is a small subset of Alzheimer's disease that is genetically determined with 100% penetrance. It provides a valuable window into studying the course of pathologic processes that leads to dementia. Arterial spin labeling (ASL) MRI is a potential AD imaging marker that non-invasively measures cerebral perfusion. In this study, we investigated the relationship of cerebral blood flow measured by pseudo-continuous ASL (pCASL) MRI with measures of cerebral metabolism (FDG PET) and amyloid deposition (Pittsburgh Compound B (PiB) PET)...
2018: NeuroImage: Clinical
Lu-Ping Li, Jon Thacker, Wei Li, Huan Tan, Chi Wang, Orly Kohn, Stuart Sprague, Pottumarthi Prasad
BACKGROUND: Identification of patients with progressive chronic kidney disease (CKD) and those likely to respond to candidate therapeutics is urgently needed. Functional MRI measurements have shown promise. However, knowledge about the consistency of the measurements is essential to conduct longitudinal studies. PURPOSE/HYPOTHESIS: To investigate the consistency of repeated functional MRI measurements in healthy subjects. STUDY TYPE: Prospective, longitudinal study...
March 8, 2018: Journal of Magnetic Resonance Imaging: JMRI
Mohamed Almuqbil, Michael J Rivkin, Masanori Takeoka, Edward Yang, Lance H Rodan
GLUT1 deficiency syndrome (GLUT1DS) is a well described neurometabolic disorder that results from impaired glucose transport into the central nervous system. GLUT1DS classically presents with infantile-onset epilepsy, progressive microcephaly, developmental delay, ataxia, dystonia, and spasticity, but a minority of patients may manifest with paroxysmal non-epileptic phenomena including hemiparesis (Wang et al., 2002). We report for the first time cerebral perfusion changes during an acute episode of hemiparesis in a 9 year old child with GLUT1DS...
February 19, 2018: European Journal of Paediatric Neurology: EJPN
James R Larkin, Manon A Simard, Alexandre A Khrapitchev, James A Meakin, Thomas W Okell, Martin Craig, Kevin J Ray, Peter Jezzard, Michael A Chappell, Nicola R Sibson
Cerebral blood flow is an important parameter in many diseases and functional studies that can be accurately measured in humans using arterial spin labelling (ASL) MRI. However, although rat models are frequently used for preclinical studies of both human disease and brain function, rat CBF measurements show poor consistency between studies. This lack of reproducibility is due, partly, to the smaller size and differing head geometry of rats compared to humans, as well as the differing analysis methodologies employed and higher field strengths used for preclinical MRI...
January 1, 2018: Journal of Cerebral Blood Flow and Metabolism
Zixuan Lin, Yang Li, Pan Su, Deng Mao, Zhiliang Wei, Jay J Pillai, Abhay Moghekar, Matthias van Osch, Yulin Ge, Hanzhang Lu
PURPOSE: Many brain diseases are associated with an alteration in blood-brain barrier (BBB) and its permeability. Current methods using contrast agent are primarily sensitive to major leakage of BBB to macromolecules, but may not detect subtle changes in BBB permeability. The present study aims to develop a novel non-contrast MRI technique for the assessment of BBB permeability to water. METHODS: The central principle is that by measuring arterially labeled blood spins that are drained into cerebral veins, water extraction fraction (E) and permeability-surface-area product (PS) of BBB can be determined...
March 1, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Xiaochuan Wang, Wenping Wei, Fengjuan Yuan, Shanhua Li, Jianzhong Lin, Jiaxing Zhang
BACKGROUND: It is known that a neurologic sequence occurs at high altitudes (HA); hence, cerebral blood flow (CBF) might vary by altitude. PURPOSE: To use arterial spin labeled (ASL) MRI to evaluate absolute CBF differences between subjects who live at HA and lowlands. STUDY TYPE: Cohort prospective trial. POPULATION: In all, 64 HA Tibetans, 19 lowland Tibetans, and 25 lowland Han subjects. FIELD STRENGTH/SEQUENCE: CBF was measured with the pulsed ASL sequence at 3T...
March 1, 2018: Journal of Magnetic Resonance Imaging: JMRI
Stavros Stivaros, Shruti Garg, Maria Tziraki, Ying Cai, Owen Thomas, Joseph Mellor, Andrew A Morris, Carly Jim, Karolina Szumanska-Ryt, Laura M Parkes, Hamied A Haroon, Daniela Montaldi, Nicholas Webb, John Keane, Francisco X Castellanos, Alcino J Silva, Sue Huson, Stephen Williams, D Gareth Evans, Richard Emsley, Jonathan Green
Background: Neurofibromatosis 1 (NF1) is a monogenic model for syndromic autism. Statins rescue the social and cognitive phenotype in animal knockout models, but translational trials with subjects > 8 years using cognition/behaviour outcomes have shown mixed results. This trial breaks new ground by studying statin effects for the first time in younger children with NF1 and co-morbid autism and by using multiparametric imaging outcomes. Methods: A single-site triple-blind RCT of simvastatin vs...
2018: Molecular Autism
Fuminori Miyoshi, Yuki Shinohara, Atsushi Kambe, Keita Kuya, Atsushi Murakami, Masamichi Kurosaki, Toshihide Ogawa
Background Detecting recurrence of glioma on magnetic resonance imaging (MRI) is getting more and more important, especially after administration of new anti-tumor agent. However, it is still hard to identify. Purpose To examine the utility of intravoxel incoherent motion (IVIM) MRI and arterial spin labeling-cerebral blood flow (ASL-CBF) for recurrent glioma after initiation of bevacizumab (BEV) treatment. Material and Methods Thirteen patients (7 men, 6 women; age range = 41-82 years) with glioma (high grade, n = 11; low grade, n = 2) were enrolled in the study...
January 1, 2018: Acta Radiologica
Yuxin Li, Weixingzi Xu, Chong Sun, Jie Lin, Jianxun Qu, Jiawen Cao, Haiqing Li, Liqin Yang
PURPOSE: To investigate the cerebral macrovascular changes as well as the relationship of large vessels and cerebral blood flow (CBF) in mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) using magnetic resonance angiography (MRA) and arterial spin labeling (ASL) perfusion MR imaging (MRI). METHODS: A total of 20 patients diagnosed with MELAS (12 males, 8 females; mean age, 23.3 years) underwent conventional MRI, time-of-flight (TOF) MRA and three dimensional ASL...
February 20, 2018: Clinical Neuroradiology
Zhengjun Li, Marta Vidorreta, Natalie Katchmar, David C Alsop, Daniel H Wolf, John A Detre
Resting state fMRI (rs-fMRI) provides imaging biomarkers of task-independent brain function that can be associated with clinical variables or modulated by interventions such as behavioral training or pharmacological manipulations. These biomarkers include time-averaged regional brain function as manifested by regional cerebral blood flow (CBF) measured using arterial spin labeled (ASL) perfusion MRI and correlated temporal fluctuations of function across brain networks with either ASL or blood oxygenation level dependent (BOLD) fMRI...
February 15, 2018: NeuroImage
Alberto Merola, Michael A Germuska, Kevin Murphy, Richard G Wise
As energy metabolism in the brain is largely oxidative, the measurement of cerebral metabolic rate of oxygen consumption (CMRO 2 ) is a desirable biomarker for quantifying brain activity and tissue viability. Currently, PET techniques based on oxygen isotopes are the gold standard for obtaining whole brain CMRO 2 maps. Among MRI techniques that have been developed as an alternative are dual calibrated fMRI (dcFMRI) methods, which exploit simultaneous measurements of BOLD and ASL signals during a hypercapnic-hyperoxic experiment to modulate brain blood flow and oxygenation...
February 14, 2018: NeuroImage
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
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
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
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)
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
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
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
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