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MRI perfusion brain

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https://www.readbyqxmd.com/read/27902858/reliable-estimation-of-microvascular-flow-patterns-in-patients-with-disrupted-blood-brain-barrier-using-dynamic-susceptibility-contrast-mri
#1
Mikkel Bo Hansen, Anna Tietze, Jayashree Kalpathy-Cramer, Elizabeth R Gerstner, Tracy T Batchelor, Leif Østergaard, Kim Mouridsen
PURPOSE: To present and quantify the performance of a method to compute tissue hemodynamic parameters from dynamic susceptibility contrast (DSC) MRI data in brain tissue with possible nonintact blood-brain barrier. THEORY AND MATERIALS AND METHODS: We propose a Bayesian scheme to obtain perfusion metrics, including capillary transit-time heterogeneity (CTH), from DSC-MRI data in the presence of contrast agent extravasation. Initial performance assessment is performed through simulations...
November 30, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27893680/the-value-of-ezis-analysis-of-tc-99m-ecd-spect-on-identifying-cerebellar-hypoperfusion-in-a-patient-with-superficial-siderosis-a-case-report
#2
Cheng-Yu Wei, Tai-Yi Chen, Ian Shih, Pai-Yi Chiu, Guang-Uei Hung, Hiroshi Matsuda
INTRODUCTION: Brain perfusion single photon computed tomography (SPECT) is a functional imaging modality and has been widely utilized in evaluation of various kinds of neurological disorders. Easy z-score imaging system (eZIS) is a computer-assisted statistical analysis, based on the comparison with age-classified ethyl cysteinate dimer (ECD) normal database, which provides objectively interpretation of Tc-99m ECD brain perfusion SPECT.Here we presented a 64-year-old male with dizziness, spin sensation, nausea, and vomiting in the emergency room, and brain computed tomography scan showed only small hypodensity lesion in cerebellum...
November 2016: Medicine (Baltimore)
https://www.readbyqxmd.com/read/27879370/validation-of-mri-determination-on-pet-measurements-in-ischemic-stroke
#3
Wolf-Dieter Heiss, Olivier Zaro Weber
The concept of the ischemic penumbra was formulated based on animal experiments showing functional impairment and electrophysiological disturbances with decreasing flow to the brain below defined values (the threshold for function) and irreversible tissue damage with blood supply further decreased (the threshold for infarction). The perfusion range between these thresholds was termed "penumbra", and restitution of flow above the functional threshold was able to reverse the deficits without permanent damage...
November 22, 2016: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
https://www.readbyqxmd.com/read/27857749/erythropoietin-reduces-apoptosis-of-brain-tissue-cells-in-rats-after-cerebral-ischemia-reperfusion-injury-a-characteristic-analysis-using-magnetic-resonance-imaging
#4
Chun-Juan Jiang, Zhong-Juan Wang, Yan-Jun Zhao, Zhui-Yang Zhang, Jing-Jing Tao, Jian-Yong Ma
Some in vitro experiments have shown that erythropoietin (EPO) increases resistance to apoptosis and facilitates neuronal survival following cerebral ischemia. However, results from in vivo studies are rarely reported. Perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) have been applied successfully to distinguish acute cerebral ischemic necrosis and penumbra in living animals; therefore, we hypothesized that PWI and DWI could be used to provide imaging evidence in vivo for the conclusion that EPO could reduce apoptosis in brain areas injured by cerebral ischemia/reperfusion...
September 2016: Neural Regeneration Research
https://www.readbyqxmd.com/read/27856651/flat-detector-computed-tomography-pbv-map-in-the-evaluation-of-presurgical-embolization-for-hypervascular-brain-tumors
#5
Li-Li Wen, Xin Zhang, Qing-Rong Zhang, Qi Wu, Shu-Juan Chen, Jin-Long Deng, Kaiyi Huang, Han-Dong Wang
BACKGROUND: Preoperative embolization of hypervascular brain tumors is frequently used to minimize intraoperative bleeding. OBJECTIVE: To explore the efficacy of embolization using flat-detector CT (FDCT) parenchymal blood volume (PBV) maps before and after the intervention. MATERIALS AND METHODS: Twenty-five patients with hypervascular brain tumors prospectively received pre- and postprocedural FDCT PBV scans using a biplane system under a protocol approved by the institutional research ethics committee...
November 17, 2016: Journal of Neurointerventional Surgery
https://www.readbyqxmd.com/read/27834593/an-mrs-and-pet-guided-biopsy-tool-for-intraoperative-neuronavigational-systems
#6
Matthew Grech-Sollars, Babar Vaqas, Gerard Thompson, Tara Barwick, Lesley Honeyfield, Kevin O'Neill, Adam D Waldman
OBJECTIVE Glioma heterogeneity and the limitations of conventional structural MRI for identifying aggressive tumor components can limit the reliability of stereotactic biopsy and, hence, tumor characterization, which is a hurdle for developing and selecting effective treatment strategies. In vivo MR spectroscopy (MRS) and PET enable noninvasive imaging of cellular metabolism relevant to proliferation and can detect regions of more highly active tumor. Here, the authors integrated presurgical PET and MRS with intraoperative neuronavigation to guide surgical biopsy and tumor sampling of brain gliomas with the aim of improving intraoperative tumor-tissue characterization and imaging biomarker validation...
November 11, 2016: Journal of Neurosurgery
https://www.readbyqxmd.com/read/27822669/asl-and-susceptibility-weighted-imaging-contribution-to-the-management-of-acute-ischaemic-stroke
#7
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
#8
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/27812502/comparison-of-unsupervised-classification-methods-for-brain-tumor-segmentation-using-multi-parametric-mri
#9
N Sauwen, M Acou, S Van Cauter, D M Sima, J Veraart, F Maes, U Himmelreich, E Achten, S Van Huffel
Tumor segmentation is a particularly challenging task in high-grade gliomas (HGGs), as they are among the most heterogeneous tumors in oncology. An accurate delineation of the lesion and its main subcomponents contributes to optimal treatment planning, prognosis and follow-up. Conventional MRI (cMRI) is the imaging modality of choice for manual segmentation, and is also considered in the vast majority of automated segmentation studies. Advanced MRI modalities such as perfusion-weighted imaging (PWI), diffusion-weighted imaging (DWI) and magnetic resonance spectroscopic imaging (MRSI) have already shown their added value in tumor tissue characterization, hence there have been recent suggestions of combining different MRI modalities into a multi-parametric MRI (MP-MRI) approach for brain tumor segmentation...
2016: NeuroImage: Clinical
https://www.readbyqxmd.com/read/27807197/venous-imaging-based-biomarkers-in-acute-ischaemic-stroke
#10
REVIEW
Josep Munuera, Gerard Blasco, María Hernández-Pérez, Pepus Daunis-I-Estadella, Antoni Dávalos, David S Liebeskind, Max Wintermark, Andrew Demchuk, Bijoy K Menon, Götz Thomalla, Kambiz Nael, Salvador Pedraza, Josep Puig
Vascular neuroimaging plays a decisive role in selecting the best therapy in patients with acute ischaemic stroke. However, compared with the arterial system, the role of veins has not been thoroughly studied. In this review, we present the major venous imaging-based biomarkers in ischaemic stroke. First, the presence of hypodense veins in the monophasic CT angiography ipsilateral to the arterial occlusion. Second, the asymmetry of venous drainage in the pathological cerebral hemisphere on CT and MRI dynamic angiography...
November 2, 2016: Journal of Neurology, Neurosurgery, and Psychiatry
https://www.readbyqxmd.com/read/27805440/quantitative-analysis-of-brain-perfusion-in-healthy-dogs-by-means-of-magnetic-resonance-imaging
#11
Antje Hartmann, Agnes Driesen, Ines E Lautenschläger, Volkher B Scholz, Martin J Schmidt
OBJECTIVE To determine values of perfusion parameters determined via MRI in the brains of healthy dogs. ANIMALS 10 healthy adult Beagles. PROCEDURES Each dog was anesthetized for MRI examination of the brain, including standard sequences and a perfusion-weighted sequence. Gadoteric acid (0.2 mmol/kg) was injected IV at a rate of 5 mL/s. A dedicated workstation was used to measure the times from contrast medium injection to arrival at an ROI (TO) and peak contrast enhancement (TTP), mean contrast medium transport time (MTT), and cerebral blood flow (CBF) in the caudate nucleus, thalamus, piriform lobe, hippocampus, semioval center, and temporal cerebral cortex...
November 2016: American Journal of Veterinary Research
https://www.readbyqxmd.com/read/27747597/quantitative-multimodal-multiparametric-imaging-in-alzheimer-s-disease
#12
Qian Zhao, Xueqi Chen, Yun Zhou
Alzheimer's disease (AD) is a progressive neurodegenerative disorder, causing changes in memory, thinking, and other dysfunction of brain functions. More and more people are suffering from the disease. Early neuroimaging techniques of AD are needed to develop. This review provides a preliminary summary of the various neuroimaging techniques that have been explored for in vivo imaging of AD. Recent advances in magnetic resonance (MR) techniques, such as functional MR imaging (fMRI) and diffusion MRI, give opportunities to display not only anatomy and atrophy of the medial temporal lobe, but also at microstructural alterations or perfusion disturbance within the AD lesions...
March 2016: Brain Informatics
https://www.readbyqxmd.com/read/27740987/imaging-of-brain-tumors
#13
Mirza A Baig, Joshua P Klein, Laszlo L Mechtler
PURPOSE OF REVIEW: Neuroimaging is an essential tool for the diagnosis and management of brain tumors. RECENT FINDINGS: Advances in neuroimaging have allowed for noninvasive visualization of tumors and have changed how brain tumors are diagnosed and treated. Presurgical planning with the use of functional MRI (fMRI) and diffusion tensor MRI helps to preserve eloquent regions of the brain and fiber tracts, thereby decreasing patients' postsurgical morbidity. With the use of susceptibility-weighted imaging (SWI) filtered phase images, diffusion-weighted studies, and perfusion imaging techniques, deciphering posttreatment effects versus tumor progression can be facilitated...
October 2016: Continuum: Lifelong Learning in Neurology
https://www.readbyqxmd.com/read/27731914/magnetic-resonance-imaging-of-ischemic-injury-produced-by-varying-severities-of-photothrombosis-differs-in-neonatal-and-adult-brain
#14
Ursula I Tuor, Min Qiao, Manasi Sule, Melissa Morgunov, Tadeusz Foniok
Stroke is a major cause of disability in adults and children. Recently, we have developed an adult rat model of minor stroke containing a peri-infarct region with a modest T2 increase and mild ischemic damage. We hypothesized that a neonatal minor stroke with mild peri-ischemic changes could also be produced, but with potential ontogenic differences. Using our minor photothrombosis method, we produced a range of severities of ischemic lesions (mini, minor, moderate and severe) within magnetic resonance imaging (MRI) slices of adult and neonatal rats...
October 12, 2016: NMR in Biomedicine
https://www.readbyqxmd.com/read/27731907/brain-capillary-transit-time-heterogeneity-in-healthy-volunteers-measured-by-dynamic-contrast-enhanced-t1-weighted-perfusion-mri
#15
Henrik B W Larsson, Mark B Vestergaard, Ulrich Lindberg, Helle K Iversen, Stig P Cramer
PURPOSE: Capillary transit time heterogeneity, measured as CTH, may set the upper limit for extraction of substances in brain tissue, e.g., oxygen. The purpose of this study was to investigate the feasibility of dynamic contrast-enhanced T1 weighted MRI (DCE-MRI) at 3 Tesla (T), in estimating CTH based on a gamma-variate model of the capillary transit time distribution. In addition, we wanted to investigate if a subtle increase of the blood-brain barrier permeability can be incorporated into the model, still allowing estimation of CTH...
October 12, 2016: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/27714551/cerebral-perfusion-alterations-in-type-2-diabetes-and-its-relation-to-insulin-resistance-and-cognitive-dysfunction
#16
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/27712906/distribution-of-intravoxel-incoherent-motion-mri-related-parameters-in-the-brain-evidence-of%C3%A2-interhemispheric-asymmetry
#17
C Wang, D Ren, Y Guo, Y Xu, Y Feng, X Zhang, Y Mei, M Chen, X Xiao
AIM: To compare intravoxel incoherent motion (IVIM) magnetic resonance imaging (MRI)-derived true diffusion (D) and perfusion fraction (f)-values of the two hemispheres to detect the presence of asymmetrical differences. MATERIALS AND METHODS: Forty-seven healthy right-handed volunteers were assessed using IVIM imaging. The interhemispheric D- and f-values were compared using paired t-tests and two related-samples Wilcoxon's test. RESULTS: Comparison of the interhemispheric D- and f-values of the grey matter revealed a significant difference in the D-value of the frontal lobe and the f-value of the temporal lobe (p=0...
October 4, 2016: Clinical Radiology
https://www.readbyqxmd.com/read/27693197/multiparametric-imaging-of-brain-hemodynamics-and-function-using-gas-inhalation-mri
#18
Peiying Liu, Babu G Welch, Yang Li, Hong Gu, Darlene King, Yihong Yang, Marco Pinho, Hanzhang Lu
Diagnosis and treatment monitoring of cerebrovascular diseases routinely require hemodynamic imaging of the brain. Current methods either only provide part of the desired information or require the injection of multiple exogenous agents. In this study, we developed a multiparametric imaging scheme for the imaging of brain hemodynamics and function using gas-inhalation MRI. The proposed technique uses a single MRI scan to provide simultaneous measurements of baseline venous cerebral blood volume (vCBV), cerebrovascular reactivity (CVR), bolus arrival time (BAT), and resting-state functional connectivity (fcMRI)...
September 28, 2016: NeuroImage
https://www.readbyqxmd.com/read/27686339/a-new-approach-to-selective-brain-cooling-by-a-ranque-hilsch-vortex-tube
#19
Mohammad Fazel Bakhsheshi, Yong Wang, Lynn Keenliside, Ting-Yim Lee
BACKGROUND: Target temperature management is the single most effective intervention and the gold standard in post-resuscitation care today. However, cooling the whole body below 33-34 °C can cause severe complications. Therefore, developing a selective brain cooling (SBC) approach which can be initiated early to induce rapid cooling and maintain the target temperature over 12-24 h before slowly rewarming brain temperature by itself alone would be advantageous. Vortex tubes are simple mechanical devices generating cold air from a stream of compressed air without applied chemical or energy...
December 2016: Intensive Care Medicine Experimental
https://www.readbyqxmd.com/read/27664828/neurovascular-unit-remodelling-in-the-subacute-stage-of-stroke-recovery
#20
Evelyn M R Lake, Paolo Bazzigaluppi, James Mester, Lynsie A M Thomason, Rafal Janik, Mary Brown, JoAnne McLaurin, Peter L Carlen, Dale Corbett, Greg J Stanisz, Bojana Stefanovic
Brain plasticity following focal cerebral ischemia has been observed in both stroke survivors and in preclinical models of stroke. Endogenous neurovascular adaptation is at present incompletely understood yet its potentiation may improve long-term functional outcome. We employed longitudinal MRI, intracranial array electrophysiology, Montoya Staircase testing, and immunofluorescence to examine function of brain vessels, neurons, and glia in addition to forelimb skilled reaching during the subacute stage of ischemic injury progression...
September 21, 2016: NeuroImage
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