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https://www.readbyqxmd.com/read/28810259/reliability-reproducibility-and-prognostic-accuracy-of-the-alberta-stroke-program-early-ct-score-on-ct-perfusion-and-non-contrast-ct-in-hyperacute-stroke
#1
Jillian Naylor, Leonid Churilov, Ziyuan Chen, Miriam Koome, Neil Rane, Bruce C V Campbell
BACKGROUND: Alberta Stroke Program Early CT Score (ASPECTS) assesses early ischemic change on non-contrast CT (NCCT). We hypothesised that assessing ASPECTS regions on CT Perfusion (CTP) rather than NCCT would improve inter-rater agreement and prognostic accuracy, particularly in patients presenting early after stroke onset. METHODS: Ischemic stroke patients treated with intravenous alteplase from 2009 to 2014 at our institution were included in this study. Inter-rater agreement and prognostic accuracy of ASPECTS across modalities were analysed by the time between stroke onset and initial NCCT, dichotomized 1st quartile versus quartiles 2-4, referred to as epochs...
August 16, 2017: Cerebrovascular Diseases
https://www.readbyqxmd.com/read/28776269/apparent-brain-temperature-imaging-with-multi-voxel-proton-magnetic-resonance-spectroscopy-compared-with-cerebral-blood-flow-and-metabolism-imaging-on-positron-emission-tomography-in-patients-with-unilateral-chronic-major-cerebral-artery-steno-occlusive-disease
#2
Takamasa Nanba, Hideaki Nishimoto, Yoshichika Yoshioka, Toshiyuki Murakami, Makoto Sasaki, Ikuko Uwano, Shunrou Fujiwara, Kazunori Terasaki, Kuniaki Ogasawara
PURPOSE: The purpose of the present study was to determine whether apparent brain temperature imaging using multi-voxel proton magnetic resonance (MR) spectroscopy correlates with cerebral blood flow (CBF) and metabolism imaging in the deep white matter of patients with unilateral chronic major cerebral artery steno-occlusive disease. METHODS: Apparent brain temperature and CBF and metabolism imaging were measured using proton MR spectroscopy and (15)O-positron emission tomography (PET), respectively, in 35 patients...
August 3, 2017: Neuroradiology
https://www.readbyqxmd.com/read/28762185/consideration-of-the-intracranial-pressure-threshold-value-for-the-initiation-of-traumatic-brain-injury-treatment-a-xenon-ct-and-perfusion-ct-study
#3
Mitsuru Honda, Ryo Ichibayashi, Ginga Suzuki, Hiroki Yokomuro, Yoshikatsu Seiki, Shigeru Sase, Taichi Kishi
BACKGROUND: Monitoring of intracranial pressure (ICP) is considered to be fundamental for the care of patients with severe traumatic brain injury (TBI) and is routinely used to direct medical and surgical therapy. Accordingly, some guidelines for the management of severe TBI recommend that treatment be initiated for ICP values >20 mmHg. However, it remained to be accounted whether there is a scientific basis to this instruction. The purpose of the present study was to clarify whether the basis of ICP values >20 mmHg is appropriate...
July 31, 2017: Neurocritical Care
https://www.readbyqxmd.com/read/28761534/efficacy-of-superficial-temporal-artery-middle-cerebral-artery-bypass-in-cerebrovascular-steno-occlusive-diseases-hemodynamics-assessed-by-perfusion-computed-tomography
#4
Woo-Keun Kwon, Taek-Hyun Kwon, Dong-Hyuk Park, Joo-Han Kim, Sung-Kon Ha
OBJECTIVES: Our purpose of this study was to assess the cerebral hemodynamic improvement with perfusion computed tomography (CT), before and after superficial temporal artery (STA) to middle cerebral artery (MCA) bypass surgery in patients with cerebrovascular steno-occlusive diseases including both moyamoya disease and nonmoyamoya steno-occlusions. MATERIALS AND METHODS: Twenty-four STA-MCA bypasses were performed to 22 patients with symptomatic cerebrovascular steno-occlusive diseases, including both moyamoya disease and nonmoyamoya steno-occlusive diseases...
July 2017: Asian Journal of Neurosurgery
https://www.readbyqxmd.com/read/28760084/optimal-dilution-of-contrast-medium-for-quantitating-parenchymal-blood-volume-using-a-flat-panel-detector
#5
Takumi Kuriyama, Nobuyuki Sakai, Mikiya Beppu, Chiaki Sakai, Hirotoshi Imamura, Iwao Kojima, Katsuhiro Masago, Nobuyuki Katakami
Objective Similar to perfusion studies after acute ischemic stroke, measuring cerebral blood volume (CBV) via C-arm computed tomography before and after therapeutic interventions may help gauge subsequent revascularization. We tested serial dilutions of intra-arterial injectable contrast medium (CM) to determine the optimal CM concentration for quantifying parenchymal blood volume by flat-panel detector imaging (FD-PBV). Methods CM was diluted via saline power injector, instituting time delays for FD-PBV studies...
January 1, 2017: Journal of International Medical Research
https://www.readbyqxmd.com/read/28752130/design-analysis-of-an-mpi-human-functional-brain-scanner
#6
Erica E Mason, Clarissa Z Cooley, Stephen F Cauley, Mark A Griswold, Steven M Conolly, Lawrence L Wald
MPI's high sensitivity makes it a promising modality for imaging brain function. Functional contrast is proposed based on blood SPION concentration changes due to Cerebral Blood Volume (CBV) increases during activation, a mechanism utilized in fMRI studies. MPI offers the potential for a direct and more sensitive measure of SPION concentration, and thus CBV, than fMRI. As such, fMPI could surpass fMRI in sensitivity, enhancing the scientific and clinical value of functional imaging. As human-sized MPI systems have not been attempted, we assess the technical challenges of scaling MPI from rodent to human brain...
2017: Int J Magn Part Imaging
https://www.readbyqxmd.com/read/28746785/half-the-story-thermal-effects-on-within-host-infectious-disease-progression-in-a-warming-climate
#7
Alexander Stewart, Pascal I Hablützel, Martha Brown, Hayley V Watson, Sophie Parker-Norman, Anya V Tober, Anna G Thomason, Ida M Friberg, Joanne Cable, Joseph A Jackson
Immune defence is temperature-dependent in cold-blooded vertebrates (CBVs) and thus directly impacted by global warming. We asked whether immunity and within-host infectious disease progression are altered in CBVs under realistic climate warming in a seasonal mid-latitude setting. Going further, we also asked how large thermal effects are in relation to the effects of other environmental variation in such a setting (critical to our ability to project infectious disease dynamics from thermal relationships alone)...
July 26, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28740980/micro-engineered-perfusable-3d-vasculatures-for-cardiovascular-diseases
#8
Nishanth Venugopal Menon, Hui Min Tay, Soon Nan Wee, King Ho Holden Li, Han Wei Hou
Vessel geometries in microengineered in vitro vascular models are important to recapitulate a pathophysiological microenvironment for the study of flow-induced endothelial dysfunction and inflammation in cardiovascular diseases. Herein, we present a simple and novel extracellular matrix (ECM) hydrogel patterning method to create perfusable vascularized microchannels of different geometries based on the concept of capillary burst valve (CBV). No surface modification is necessary and the method is suitable for different ECM types including collagen, matrigel and fibrin...
July 25, 2017: Lab on a Chip
https://www.readbyqxmd.com/read/28736310/non-bold-contrast-for-laminar-fmri-in-humans-cbf-cbv-and-cmro2
#9
REVIEW
Laurentius Huber, Kâmil Uludağ, Harald E Möller
Functional magnetic resonance imaging (fMRI) using the blood oxygenation level-dependent (BOLD) contrast indirectly probes neuronal activity changes via evoked cerebral blood flow (CBF), cerebral blood volume (CBV) and cerebral metabolic rate of oxygen (CMRO2) changes. The gradient-echo BOLD signal is mostly sensitive to ascending veins in the tissue and to pial veins. Thereby, the achievable spatial specificity to neuronal activation is limited. Furthermore, the non-linear interaction of CBF, CBV and CMRO2 can hamper quantitative interpretations of the BOLD signal across cortical depths with different baseline physiology...
July 20, 2017: NeuroImage
https://www.readbyqxmd.com/read/28729160/echo-time-dependence-of-the-bold-response-transients-a-window-into-brain-functional-physiology
#10
Martin Havlicek, Dimo Ivanov, Benedikt A Poser, Kamil Uludag
The blood oxygenation level-dependent (BOLD) fMRI response to neuronal activation results from a complex interplay of induced metabolic and vascular changes. Thus, its transients, such as initial overshoot and post-stimulus undershoot, provide a window into the dynamic relationships of the underlying physiological variables. In this study, we propose multi-echo fMRI as a tool to investigate the physiological underpinnings of the BOLD signal, in particular, and brain functional physiology, in general. In the human visual cortex at 3 T, we observed that the BOLD response is nonlinearly dependent on echo-time (TE) and the amount of nonlinearity varies during the entire time-course...
July 18, 2017: NeuroImage
https://www.readbyqxmd.com/read/28729141/effects-of-transjugular-intrahepatic-portosystemic-shunt-tips-on-blood-volume-distribution-in-patients-with-cirrhosis
#11
Troels M Busk, Flemming Bendtsen, Jens H Henriksen, Stefan Fuglsang, Jens O Clemmesen, Fin S Larsen, Søren Møller
BACKGROUND: Cirrhosis is accompanied by portal hypertension with splanchnic and systemic arterial vasodilation, and central hypovolaemia. A transjugular intrahepatic portosystemic shunt (TIPS) alleviates portal hypertension, but also causes major haemodynamic changes. AIMS: To investigate effects of TIPS on regional blood volume distribution, and systemic haemodynamics. METHODS: Thirteen cirrhotic patients had their regional blood volume distribution determined with gamma-camera technique before and after TIPS...
June 27, 2017: Digestive and Liver Disease
https://www.readbyqxmd.com/read/28718993/role-of-fdg-pet-mri-fdg-pet-ct-and-dynamic-susceptibility-contrast-perfusion-mri-in-differentiating-radiation-necrosis-from-tumor-recurrence-in-glioblastomas
#12
Mojgan Hojjati, Chaitra Badve, Vasant Garg, Curtis Tatsuoka, Lisa Rogers, Andrew Sloan, Peter Faulhaber, Pablo R Ros, Leo J Wolansky
BACKGROUND AND PURPOSE: To compare the utility of quantitative PET/MRI, dynamic susceptibility contrast (DSC) perfusion MRI (pMRI), and PET/CT in differentiating radiation necrosis (RN) from tumor recurrence (TR) in patients with treated glioblastoma multiforme (GBM). METHODS: The study included 24 patients with GBM treated with surgery, radiotherapy, and temozolomide who presented with progression on imaging follow-up. All patients underwent PET/MRI and pMRI during a single examination...
July 18, 2017: Journal of Neuroimaging: Official Journal of the American Society of Neuroimaging
https://www.readbyqxmd.com/read/28689261/investigation-of-cognitive-circuits-using-steady-state-cerebral-blood-volume-and-diffusion-tensor-imaging-in-patients-with-mild-cognitive-impairment-following-electrical-injury
#13
Chang-Hyun Park, Cheong Hoon Seo, Myung Hun Jung, So Young Joo, Soyeon Jang, Ho Young Lee, Suk Hoon Ohn
PURPOSE: We utilized cerebral blood volume (CBV) magnetic resonance imaging and diffusion tensor imaging (DTI) to investigate changes in cognitive networks in patients experiencing cognitive dysfunction following electrical injury. METHODS: Cognitive function was assessed across various domains, including attention, verbal memory, executive function, and language. Depressive symptoms were also evaluated. CBV maps and DTI measures were obtained from 24 patients (age, 41...
July 8, 2017: Neuroradiology
https://www.readbyqxmd.com/read/28684456/optimization-of-dsc-mri-echo-times-for-cbv-measurements-using-error-analysis-in-a-pilot-study-of-high-grade-gliomas
#14
L C Bell, M D Does, A M Stokes, L C Baxter, K M Schmainda, A C Dueck, C C Quarles
BACKGROUND AND PURPOSE: The optimal TE must be calculated to minimize the variance in CBV measurements made with DSC MR imaging. Simulations can be used to determine the influence of the TE on CBV, but they may not adequately recapitulate the in vivo heterogeneity of precontrast T2*, contrast agent kinetics, and the biophysical basis of contrast agent-induced T2* changes. The purpose of this study was to combine quantitative multiecho DSC MRI T2* time curves with error analysis in order to compute the optimal TE for a traditional single-echo acquisition...
July 6, 2017: AJNR. American Journal of Neuroradiology
https://www.readbyqxmd.com/read/28671554/a-machine-learning-based-analysis-for-the-recognition-of-progressive-central-hypovolemia
#15
Frank Cornelis Bennis, Björn Van der Ster, Johannes Van Lieshout, Peter Andriessen, Tammo Delhaas
Traditional patient monitoring during surgery include heart rate (HR), blood pressure (BP) and peripheral oxygen saturation. However, their use as predictors for central hypovolemia is limited, which may lead to cerebral hypoperfusion. The aim of this study was to develop a monitoring model that can indicate a decrease in central blood volume (CBV) in an early stage. Approach: Twenty-eight healthy subjects (age 18-50 yr) were included. Lower body negative pressure (-50 mmHg) was applied to induce central hypovolemia until onset of pre-syncope...
July 3, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/28664954/soft-skin-mounted-microfluidic-systems-for-measuring-secretory-fluidic-pressures-generated-at-the-surface-of-the-skin-by-eccrine-sweat-glands
#16
Jungil Choi, Yeguang Xue, Wei Xia, Tyler R Ray, Jonathan T Reeder, Amay J Bandodkar, Daeshik Kang, Shuai Xu, Yonggang Huang, John A Rogers
During periods of activity, sweat glands produce pressures associated with osmotic effects to drive liquid to the surface of the skin. The magnitudes of these pressures may provide insights into physiological health, the intensity of physical exertion, psychological stress factors and/other information of interest, yet they are currently unknown due to absence of means for non-invasive measurement. This paper introduces a thin, soft wearable microfluidic system that mounts onto the surface of the skin to enable precise and routine measurements of secretory fluidic pressures generated at the surface of the skin by eccrine sweat glands (surface SPSG, or s-SPSG) at nearly any location on the body...
July 25, 2017: Lab on a Chip
https://www.readbyqxmd.com/read/28658875/efficacy-of-perfusion-computed-tomography-pct-in-differentiating-high-grade-gliomas-from-low-grade-gliomas-lymphomas-metastases-and-abscess
#17
Lakshmikanth Halegubbi Karegowda, Rajagopal Kadavigere, Poonam Mohan Shenoy, Samir Mustaffa Paruthikunnan
INTRODUCTION: Tumoural angioneogenesis and its quantification are important in predicting the tumour grade and in the management with respect to the treatment available and to assess the response to treatment and the prognosis. It also plays major role in the growth and spread of tumours. Hence, a need arises for non-invasive in vivo methods to assess tumour angioneogenesis and tumour grade at the time of presentation and for monitoring the response during treatment and follow up. In this regard Perfusion Computed Tomography (PCT) can be easily added into routine CT studies to obtain such information on lesion physiology along with its morphology...
May 2017: Journal of Clinical and Diagnostic Research: JCDR
https://www.readbyqxmd.com/read/28631203/assessment-of-mri-contrast-agent-concentration-by-quantitative-susceptibility-mapping-qsm-application-to-estimation-of-cerebral-blood-volume-during-steady-state
#18
Emelie Lind, Linda Knutsson, Robin Kämpe, Freddy Ståhlberg, Ronnie Wirestam
OBJECTIVE: One major issue in dynamic susceptibility contrast MRI (DSC-MRI) is to accurately determine contrast agent (CA) concentration, since T2* relaxivity in vivo is generally unknown and varies between blood and tissue. In this study, quantitative susceptibility mapping (QSM) was used for quantification of CA concentration. MATERIALS AND METHODS: A DSC-MRI protocol, including phase data acquisition, was applied to 20 healthy volunteers in a test-retest study...
June 19, 2017: Magma
https://www.readbyqxmd.com/read/28596159/in-vivo-relationship-between-hypoxia-and-angiogenesis-in-human-glioblastoma-a-multimodal-imaging-study
#19
Keven Ferreira da Ponte, David Hassanein Berro, Solène Collet, Jean-Marc Constans, Evelyne Emery, Samuel Valable, Jean-Sébastien Guillamo
Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor. This aggressiveness is in part attributed to the closely interrelated phenomena, tumor hypoxia and angiogenesis, although few in vivo data exist in human brain tumors. This work aims to study hypoxia and angiogenesis, in vivo and in situ, in patients admitted with GBM using multimodal imaging. Methods: 23 GBM patients were assessed by [(18)F]-FMISO PET and conventional and perfusion MRI prior to surgery. The level and location of hypoxia ([(18)F]-FMISO uptake, evaluated by tumor/blood ratio, T/B), vascularization (cerebral blood volume, CBV) and vascular permeability (contrast enhancement after gadolinium injection) were analyzed...
June 8, 2017: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
https://www.readbyqxmd.com/read/28587332/three-dimensional-arterial-spin-labeling-imaging-and-dynamic-susceptibility-contrast-perfusion-weighted-imaging-value-in-diagnosing-glioma-grade-prior-to-surgery
#20
Hong Ma, Zizheng Wang, Kai Xu, Zefeng Shao, Chun Yang, Peng Xu, Xiaohua Liu, Chunfeng Hu, Xin Lu, Yutao Rong
The current study aimed to investigate whole-brain three-dimensional arterial spin labeling imaging (3D ASL) and dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI), in regards to their diagnostic value of preoperative glioma grade. The parameter values obtained after correction will be correlated with the diagnostic value of 3D ASL and DSC-PWI perfusion. In the current study, 50 patients with gliomas confirmed by pathology were used, including 27 low-grade gliomas (LGGs) and 23 high-grade gliomas (HGGs)...
June 2017: Experimental and Therapeutic Medicine
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