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Brain perfusion imaging

Wenxian Li, Youzhen Feng, Weibiao Lu, Xie Xie, Zhilin Xiong, Zhen Jing, Xiangran Cai, Li'an Huang
PURPOSE: To determine the morphological changes of intracranial arteries and whole-brain perfusion in undetermined isolated vertigo (UIV) patients using 320-detector row computed tomography (CT). METHODS: A total of 150 patients who underwent CT angiography (CTA) and CT perfusion (CTP) imaging were divided into UIV group and benign paroxysmal positional vertigo (BPPV) group. Sixty individuals with sex- and age-matched without vertigo and cerebral diseases served as the control...
November 15, 2016: Journal of the Neurological Sciences
Gabor Nagy, Viktoria Baksa, Alexandra Kiss, Melinda Turani, Gaspar Banfalvi
The toxicity of gadolinium is reduced by chelating agents that render this heavy metal into contrast complexes used for medical magnetic resonance imaging. However, the dissociation of gadolinium chelates is known to generate Gd(3+) ions, the cellular toxicity of which has not been tested in details. The cytotoxic effects of Gd(III) ions were evaluated by monitoring the proliferation, measuring the cellular motility and following chromatin changes in various cell lines upon Gd(3+) treatment. Measurements applied long-term scanning microscopy and a perfusion platform that replaced the medium with test solutions, bypassed physical contact with the cell culture during experiments, and provided uninterrupted high time-resolution time-lapse photomicrography for an extended period of time...
October 22, 2016: Apoptosis: An International Journal on Programmed Cell Death
Nobuhiro Yada, Hideo Onishi, Masahiro Miyai, Kentarou Ozasa, Masuo Haramoto, Yasushi Yamamoto, Shuhei Yamaguchi, Hajime Kitagaki
PURPOSE: This study aimed to verify the resolution recovery for each collimator in the brain perfusion image. METHOD: To verify the effect of the resolution recovery for each collimator, we evaluated via the three-dimensional brain phantom (phantom) and the normal brain perfusion single photon emission computed tomography (SPECT) data. These data were reconstructed using the three-dimensional ordered subset expectation maximization method (3D-OSEM) (Evolution for bone(TM)) that was performed with scatter correction, attenuation correction, and resolution recovery (RR)...
2016: Nihon Hoshasen Gijutsu Gakkai Zasshi
J Wu, S Dehkharghani, F Nahab, J Allen, D Qiu
BACKGROUND AND PURPOSE: Measuring cerebrovascular reactivity with the use of vasodilatory stimuli, such as acetazolamide, is useful for chronic cerebrovascular steno-occlusive disease. The purpose of this study was to evaluate the effects of acetazolamide on the assessment of hemodynamic impairment and functional connectivity by using noninvasive resting-state blood oxygen level-dependent MR imaging. MATERIALS AND METHODS: A 20-minute resting-state blood oxygen level-dependent MR imaging scan was acquired with infusion of acetazolamide starting at 5 minutes after scan initiation...
October 6, 2016: AJNR. American Journal of Neuroradiology
Sven Haller, Greg Zaharchuk, David L Thomas, Karl-Olof Lovblad, Frederik Barkhof, Xavier Golay
Arterial spin labeling (ASL) is a magnetic resonance (MR) imaging technique used to assess cerebral blood flow noninvasively by magnetically labeling inflowing blood. In this article, the main labeling techniques, notably pulsed and pseudocontinuous ASL, as well as emerging clinical applications will be reviewed. In dementia, the pattern of hypoperfusion on ASL images closely matches the established patterns of hypometabolism on fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) images due to the close coupling of perfusion and metabolism in the brain...
November 2016: Radiology
Kazuhiro Murayama, Kazuhiro Katada, Motoharu Hayakawa, Hiroshi Toyama
OBJECTIVE: We aimed to clarify the cause of shortened mean transit time (MTT) in acute ischemic cerebrovascular disease and examined its relationship with reperfusion. METHODS: Twenty-three patients with acute ischemic cerebrovascular disease underwent whole-brain computed tomography perfusion (CTP). The maximum MTT (MTTmax), minimum MTT (MTTmin), ratio of maximum and minimum MTT (MTTmin/max), and minimum cerebral blood volume (CBV) (CBVmin) were measured by automatic region of interest analysis...
October 7, 2016: Journal of Computer Assisted Tomography
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
Lara A Brandão, Mauricio Castillo
Proton magnetic resonance spectroscopy (H-MRS) may be helpful in suggesting tumor histology and tumor grade and may better define tumor extension and the ideal site for biopsy compared with conventional magnetic resonance (MR) imaging. A multifunctional approach with diffusion-weighted imaging, perfusion-weighted imaging, and permeability maps, along with H-MRS, may enhance the accuracy of the diagnosis and characterization of brain tumors and estimation of therapeutic response. Integration of advanced imaging techniques with conventional MR imaging and the clinical history help to improve the accuracy, sensitivity, and specificity in differentiating tumors and nonneoplastic lesions...
November 2016: Magnetic Resonance Imaging Clinics of North America
Brent Griffith, Rajan Jain
Perfusion imaging is a method for assessing the flow of blood occurring at the tissue level and can be accomplished by both CT and MR perfusion techniques. The use of perfusion imaging has increased substantially in the past decade, particularly in neuro-oncologic imaging, where it is has been used for brain tumor grading and directing biopsies or targeted therapy, as well as for the evaluation of treatment response and disease progression. This article discusses the basic principles and techniques of perfusion imaging, as well as its applications in neuro-oncology...
November 2016: Magnetic Resonance Imaging Clinics of North America
Arnav Mehta, Ketan Ghaghada, Srinivasan Mukundan
The first generation of cross-sectional brain imaging using computed tomography (CT), ultrasonography, and eventually MR imaging focused on determining structural or anatomic changes associated with brain disorders. The current state-of-the-art imaging, functional imaging, uses techniques such as CT and MR perfusion that allow determination of physiologic parameters in vivo. In parallel, tissue-based genomic, transcriptomic, and proteomic profiling of brain tumors has created several novel and exciting possibilities for molecular targeting of brain tumors...
November 2016: Magnetic Resonance Imaging Clinics of North America
Jerrold L Boxerman, Mark S Shiroishi, Benjamin M Ellingson, Whitney B Pope
Dynamic susceptibility contrast (DSC) MR imaging, a perfusion-weighted MR imaging technique typically used in neuro-oncologic applications for estimating the relative cerebral blood volume within brain tumors, has demonstrated much potential for determining prognosis, predicting therapeutic response, and assessing early treatment response of gliomas. This review highlights recent developments using DSC-MR imaging and emphasizes the need for technical standardization and validation in prospective studies in order for this technique to become incorporated into standard-of-care imaging for patients with brain tumors...
November 2016: Magnetic Resonance Imaging Clinics of North America
Robert S Miletich
PURPOSE OF REVIEW: Positron emission tomography (PET) and single-photon emission computed tomography (SPECT) are now available for routine clinical applications in neurology. This article discusses their diagnostic use in dementia, brain tumors, epilepsy, parkinsonism, cerebrovascular disease, and traumatic brain injury. RECENT FINDINGS: Neuromolecular imaging, also known as nuclear neurology, involves clinical imaging of both basal regional physiology (perfusion, metabolism, and transport mechanisms) and specific neurochemical physiology (currently, only the dopamine transporter)...
October 2016: Continuum: Lifelong Learning in Neurology
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
Charles L Francoeur, Stephan A Mayer
For patients who survive the initial bleeding event of a ruptured brain aneurysm, delayed cerebral ischemia (DCI) is one of the most important causes of mortality and poor neurological outcome. New insights in the last decade have led to an important paradigm shift in the understanding of DCI pathogenesis. Large-vessel cerebral vasospasm has been challenged as the sole causal mechanism; new hypotheses now focus on the early brain injury, microcirculatory dysfunction, impaired autoregulation, and spreading depolarization...
October 14, 2016: Critical Care: the Official Journal of the Critical Care Forum
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
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
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
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 3, 2016: Clinical Radiology
Marc C Mabray, Soonmee Cha
This article presents a summary of advanced MR imaging techniques and their use in the evaluation of patients with brain tumors. It reviews diffusion-weighted imaging, diffusion-tensor imaging, T2* susceptibility-sensitive imaging, MR spectroscopy, MR perfusion, and functional MR imaging, and discusses their current roles in the evaluation of patients with brain tumors.
November 2016: Neuroimaging Clinics of North America
Ramon Francisco Barajas, Soonmee Cha
Metastatic cancer to the central nervous system is primarily deposited by hematogenous spread in various anatomically distinct regions: calvarial, pachymeningeal, leptomeningeal, and brain parenchyma. A patient's overall clinical status and the information needed to make treatment decisions are the primary considerations in initial imaging modality selection. Contrast-enhanced MR imaging is the preferred imaging modality. Morphologic MR imaging is limited to delineating anatomic deraignment of tissues. Dynamic susceptibility contrast-enhanced perfusion and diffusion-weighted physiology-based MR imaging sequences have been developed that complement morphologic MR imaging by providing additional diagnostic information...
November 2016: Neuroimaging Clinics of North America
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