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https://www.readbyqxmd.com/read/28195664/an-adaptive-model-for-rapid-and-direct-estimation-of-extravascular-extracellular-space-in-dynamic-contrast-enhanced-mri-studies
#1
Azimeh N V Dehkordi, Alireza Kamali-Asl, James R Ewing, Ning Wen, Indrin J Chetty, Hassan Bagher-Ebadian
Extravascular extracellular space (ve ) is a key parameter to characterize the tissue of cerebral tumors. This study introduces an artificial neural network (ANN) as a fast, direct, and accurate estimator of ve from a time trace of the longitudinal relaxation rate, ΔR1 (R1  = 1/T1 ), in DCE-MRI studies. Using the extended Tofts equation, a set of ΔR1 profiles was simulated in the presence of eight different signal to noise ratios. A set of gain- and noise-insensitive features was generated from the simulated ΔR1 profiles and used as the ANN training set...
February 14, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28192548/association-of-collateral-blood-vessels-detected-by-arterial-spin-labeling-magnetic-resonance-imaging-with-neurological-outcome-after-ischemic-stroke
#2
Adam de Havenon, David R Haynor, David L Tirschwell, Jennifer J Majersik, Gordon Smith, Wendy Cohen, Jalal B Andre
Importance: Robust collateral blood vessels have been associated with better neurologic outcome following acute ischemic stroke (AIS). The most commonly used methods for identifying collaterals are contrast-based angiographic imaging techniques, which are not possible in all patients after AIS. Objective: To assess the association between the presence of collateral vessels identified using arterial spin labeling (ASL) magnetic resonance imaging, a technique that does not require exogenous administration of contrast, and neurologic outcome in patients after AIS...
February 13, 2017: JAMA Neurology
https://www.readbyqxmd.com/read/28178960/ultrasound-and-dynamic-functional-imaging-in-vascular-cognitive-impairment-and-alzheimer-s-disease
#3
REVIEW
Branko Malojcic, Panteleimon Giannakopoulos, Farzaneh A Sorond, Elsa Azevedo, Marina Diomedi, Janja Pretnar Oblak, Nicola Carraro, Marina Boban, Laszlo Olah, Stephan J Schreiber, Aleksandra Pavlovic, Zsolt Garami, Nantan M Bornstein, Bernhard Rosengarten
BACKGROUND: The vascular contributions to neurodegeneration and neuroinflammation may be assessed by magnetic resonance imaging (MRI) and ultrasonography (US). This review summarises the methodology for these widely available, safe and relatively low cost tools and analyses recent work highlighting their potential utility as biomarkers for differentiating subtypes of cognitive impairment and dementia, tracking disease progression and evaluating response to treatment in various neurocognitive disorders...
February 9, 2017: BMC Medicine
https://www.readbyqxmd.com/read/28168990/clinical-assessment-of-cerebral-hemodynamics-in-moyamoya-disease-via-multiple-inversion-time-arterial-spin-labeling-and-dynamic-susceptibility-contrast-magnetic-resonance-imaging-a-comparative-study
#4
Peng-Gang Qiao, Cong Han, Zhi-Wei Zuo, Yi-Tuo Wang, Josef Pfeuffer, Lian Duan, Tianyi Qian, Gong-Jie Li
BACKGROUND AND PURPOSE: For Moyamoya disease (MMD) patients, accurate hemodynamic assessment is critical for treatment selection and efficacy assessment. This study aims to investigate the clinical value of mTI-ASL in assessing the cerebral hemodynamics of MMD patients before and after revascularization, relative to DSC-MRI. MATERIALS AND METHODS: Forty-one MMD patients underwent mTI-ASL and DSC-MRI during blood perfusion. Quantitative parameters for the bilateral supply vessels of middle and anterior cerebral arteries, including DSC-TTP, DSC-CBF, ASL-BAT, and ASL-CBF were measured...
February 3, 2017: Journal of Neuroradiology. Journal de Neuroradiologie
https://www.readbyqxmd.com/read/28152238/assessment-of-segmental-myocardial-blood-flow-and-myocardial-perfusion-reserve-by-adenosine-stress-myocardial-arterial-spin-labeling-perfusion-imaging
#5
Andrew J Yoon, Hung Phi Do, Steven Cen, Michael W Fong, Farhood Saremi, Mark L Barr, Krishna S Nayak
PURPOSE: To determine the feasibility of measuring increases in myocardial blood flow (MBF) and myocardial perfusion reserve (MPR) on a per-segment basis using arterial spin labeled (ASL) magnetic resonance imaging (MRI) with adenosine vasodilator stress in normal human myocardium. MATERIALS AND METHODS: Myocardial ASL scans at rest and during adenosine infusion were incorporated into a routine 3T MR adenosine-induced vasodilator stress protocol and were performed in 10 healthy human volunteers...
February 2, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28145075/biomarkers-designs-and-interpretations-of-resting-state-fmri-in-translational-pharmacological-research-a-review-of-state-of-the-art-challenges-and-opportunities-for-studying-brain-chemistry
#6
REVIEW
Najmeh Khalili-Mahani, Serge A R B Rombouts, Matthias J P van Osch, Eugene P Duff, Felix Carbonell, Lisa D Nickerson, Lino Becerra, Albert Dahan, Alan C Evans, Jean-Paul Soucy, Richard Wise, Alex P Zijdenbos, Joop M van Gerven
A decade of research and development in resting-state functional MRI (RSfMRI) has opened new translational and clinical research frontiers. This review aims to bridge between technical and clinical researchers who seek reliable neuroimaging biomarkers for studying drug interactions with the brain. About 85 pharma-RSfMRI studies using BOLD signal (75% of all) or arterial spin labeling (ASL) were surveyed to investigate the acute effects of psychoactive drugs. Experimental designs and objectives include drug fingerprinting dose-response evaluation, biomarker validation and calibration, and translational studies...
February 1, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28143434/combination-of-ivim-dwi-and-3d-asl-for-differentiating-true-progression-from-pseudoprogression-of-glioblastoma-multiforme-after-concurrent-chemoradiotherapy-study-protocol-of-a-prospective-diagnostic-trial
#7
Zhi-Cheng Liu, Lin-Feng Yan, Yu-Chuan Hu, Ying-Zhi Sun, Qiang Tian, Hai-Yan Nan, Ying Yu, Qian Sun, Wen Wang, Guang-Bin Cui
BACKGROUND: Standard therapy for Glioblastoma multiforme (GBM) involves maximal safe tumor resection followed with radiotherapy and concurrent adjuvant temozolomide. About 20 to 30% patients undergoing their first post-radiation MRI show increased contrast enhancement which eventually recovers without any new treatment. This phenomenon is referred to as pseudoprogression. Differentiating tumor progression from pseudoprogression is critical for determining tumor treatment, yet this capacity remains a challenge for conventional magnetic resonance imaging (MRI)...
February 1, 2017: BMC Medical Imaging
https://www.readbyqxmd.com/read/28121708/cerebral-blood-flow-and-cognitive-function-in-hiv-infected-men-with-sustained-suppressed-viremia-on-combination-antiretroviral-therapy
#8
Tanja Su, Henk-Jan Mutsaerts, Matthan W A Caan, Ferdinand W N M Wit, Judith Schouten, Gert J Geurtsen, David J Sharp, Maria Prins, E Richard, Peter Portegies, Peter Reiss, Charles B Majoie
OBJECTIVE: To assess if HIV-infected patients on long-term successful combination antiretroviral therapy (cART) show cerebral blood flow (CBF) alterations in comparison to HIV-uninfected, otherwise similar controls. To explore whether such alterations are associated with HIV-associated cognitive impairment and to explore potential determinants of CBF alterations in HIV. DESIGN: Cross-sectional comparison of CBF in an observational cohort study. METHODS: Clinical, cognitive and magnetic resonance imaging (MRI) data of 100 middle-aged aviremic HIV-infected men on cART and 69 HIV-uninfected controls were collected and compared...
January 24, 2017: AIDS
https://www.readbyqxmd.com/read/28112022/structural-and-physiological-neurovascular-changes-in-idiopathic-parkinson-s-disease-and-its-clinical-phenotypes
#9
Sarah Al-Bachari, Rishma Vidyasagar, Hedley Ca Emsley, Laura M Parkes
Neurovascular changes are likely to interact importantly with the neurodegenerative process in idiopathic Parkinson's disease (IPD). Markers of neurovascular status (NVS) include white matter lesion (WML) burden and arterial spin labelling (ASL) measurements of cerebral blood flow (CBF) and arterial arrival time (AAT). We investigated NVS in IPD, including an analysis of IPD clinical phenotypes, by comparison with two control groups, one with a history of clinical cerebrovascular disease (CVD) (control positive, CP) and one without CVD (control negative, CN)...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/28109103/-value-of-diffusion-weighted-imaging-1-h-magnetic-resonance-spectroscopy-and-3d-whole-brain-arterial-spin-labeling-in-the-diagnosis-of-medulloblastoma
#10
Dong-Liang Cheng, Wen-Sheng Wang, Yi-Xin Hu, Meng-Lin Chen, Ge Wen, Li-Na Cheng, Jing Wu, Liu-Qing Yan
OBJECTIVE: To explore the value of diffusion-weighted imaging (DWI), (1)H-magnetic resonance spectroscopy (1H-MRS) and 3D whole-brain arterial spin labeling (3D ASL) in the diagnosis of medulloblastoma in the posterior cranial fossa. METHODS: The magnetic resonance imaging (MRI) findings of 16 patients with pathologically confirmed medulloblastoma in the posterior cranial fossa were analyzed retrospectively. All the patients were examined with plane and enhanced brain MRI scans; 5 patients also underwent examinations with DWI, 12 with MRS, and 5 with 3D ASL...
January 20, 2017: Nan Fang Yi Ke da Xue Xue Bao, Journal of Southern Medical University
https://www.readbyqxmd.com/read/28101675/operative-planning-aid-for-optimal-endoscopic-third-ventriculostomy-entry-points-in-pediatric-cases
#11
Zsolt Zador, David J Coope, Abteen Mostofi, Ian D Kamaly-Asl
OBJECT: Endoscopic third ventriculostomy (ETV) uses anatomical spaces of the ventricular system to reach the third ventricle floor and create an alternative pathway for cerebrospinal fluid flow. Optimal ETV trajectories have been previously proposed in the literature, designed to grant access to the third ventricle floor without a displacement of eloquent periventricular structures. However, in hydrocephalus, there is a significant variability to the configuration of the ventricular system, implying that the optimal ETV trajectory and cranial entry point needs to be planned on a case-by-case basis...
January 18, 2017: Child's Nervous System: ChNS: Official Journal of the International Society for Pediatric Neurosurgery
https://www.readbyqxmd.com/read/28095387/mri-of-cerebellar-infarction
#12
Laurens J L De Cocker, Karl-Olof Lövblad, Jeroen Hendrikse
BACKGROUND: MRI is the imaging modality of choice for diagnosing brain infarction. Because of few or atypical clinical symptoms and a relatively low sensitivity of CT scans, many cerebellar infarctions may be detected only with MRI. With adequate recognition of cerebellar infarction on MRI and prompt initiation or optimisation of preventive therapeutic measures, more dramatic strokes may be avoided in selected cases. SUMMARY: We first briefly review the clinical presentation of cerebellar infarctions, followed by a short refresher on cerebellar anatomy and pathophysiological mechanisms of cerebellar infarcts...
January 18, 2017: European Neurology
https://www.readbyqxmd.com/read/28092848/the-initial-use-of-arterial-spin-labeling-perfusion-and-diffusion-weighted-magnetic-resonance-images-in-the-diagnosis-of-nonconvulsive-partial-status-epileptics
#13
Takafumi Shimogawa, Takato Morioka, Tetsuro Sayama, Sei Haga, Yuka Kanazawa, Kei Murao, Shuji Arakawa, Ayumi Sakata, Koji Iihara
BACKGROUND: In the diagnosis of nonconvulsive status epilepticus (NCSE), capture of ongoing ictal electroencephalographic (EEG) findings is the gold standard; however, this is practically difficult without continuous EEG monitoring facilities. Magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI) and perfusion MRI with arterial spin labeling (ASL), have been applied mainly in emergency situations. Recent reports have described that ictal MRI findings, including ictal hyperperfusion on ASL and cortical hyperintensity of cytotoxic edema on DWI, can be obtained from epileptically activated cortex...
December 21, 2016: Epilepsy Research
https://www.readbyqxmd.com/read/28092411/measurement-of-arterial-transit-time-and-renal-blood-flow-using-pseudocontinuous-asl-mri-with-multiple-post-labeling-delays-feasibility-reproducibility-and-variation
#14
Dong Won Kim, Woo Hyun Shim, Seong Kuk Yoon, Jong Yeong Oh, Jeong Kon Kim, Hoesu Jung, Tsuyoshi Matsuda, Dongeun Kim
PURPOSE: To evaluate the feasibility, reproducibility, and variation of renal perfusion and arterial transit time (ATT) using pseudocontinuous arterial spin labeling magnetic resonance imaging (PCASL MRI) in healthy volunteers. MATERIALS AND METHODS: PCASL MRI at 3T was performed in 25 healthy volunteers on two different occasions. The ATT and ATT-corrected renal blood flow (ATT-cRBF) were calculated at four different post-labeling delay points (0.5, 1.0, 1.5, and 2...
January 16, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28063376/a-comprehensive-non-invasive-framework-for-diagnosing-prostate-cancer
#15
Islam Reda, Ahmed Shalaby, Mohammed Elmogy, Ahmed Abou Elfotouh, Fahmi Khalifa, Mohamed Abou El-Ghar, Ehsan Hosseini-Asl, Georgy Gimel'farb, Naoufel Werghi, Ayman El-Baz
Early detection of prostate cancer increases chances of patients' survival. Our automated non-invasive system for computer-aided diagnosis (CAD) of prostate cancer segments the prostate on diffusion-weighted magnetic resonance images (DW-MRI) acquired at different b-values, estimates its apparent diffusion coefficients (ADC), and classifies their descriptors - empirical cumulative distribution functions (CDF) - with a trained deep learning network. To segment the prostate, an evolving geometric (level-set-based) deformable model is guided by a speed function depending on intensity attributes extracted from the DW-MRI with nonnegative matrix factorization (NMF)...
February 1, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28048262/su-g-iep1-07-inaccuracy-of-lesion-blood-flow-quantification-related-to-the-proton-density-reference-image-in-arterial-spin-labeling-mri-of-brain-tumors
#16
M Jen, J Johnson, P Hou, H Liu
PURPOSE: Cerebral blood flow quantification in arterial spin labeling (ASL) MRI requires an estimate of the equilibrium magnetization of blood, which is often obtained by a set of proton density (PD) reference image. Normally, a constant blood-brain partition coefficient is assumed across the brain. However, this assumption may not be valid for brain lesions. This study aimed to evaluate the impact of lesion-related PD variations on ASL quantification in patients with brain tumors. METHODS: MR images for posttreatment evaluation of 42 patients with brain tumors were retrospectively analyzed...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28046971/th-cd-206-01-expectation-maximization-algorithm-based-tissue-mixture-quantification-for-perfusion-mri
#17
H Han, Z Liang, L Li, L Xing
PURPOSE: To investigate the feasibility of estimating the tissue mixture perfusions and quantifying cerebral blood flow change in arterial spin labeled (ASL) perfusion MR images. METHODS: The proposed perfusion MR image analysis framework consists of 5 steps: (1) Inhomogeneity correction was performed on the T1- and T2-weighted images, which are available for each studied perfusion MR dataset. (2) We used the publicly available FSL toolbox to strip off the non-brain structures from the T1- and T2-weighted MR images...
June 2016: Medical Physics
https://www.readbyqxmd.com/read/28045051/randomized-trial-on-the-effects-of-a-combined-physical-cognitive-training-in-aged-mci-subjects-the-train-the-brain-study
#18
(no author information available yet)
Age-related cognitive impairment and dementia are an increasing societal burden. Epidemiological studies indicate that lifestyle factors, e.g. physical, cognitive and social activities, correlate with reduced dementia risk; moreover, positive effects on cognition of physical/cognitive training have been found in cognitively unimpaired elders. Less is known about effectiveness and action mechanisms of physical/cognitive training in elders already suffering from Mild Cognitive Impairment (MCI), a population at high risk for dementia...
January 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/27988320/heterogeneous-increases-of-regional-cerebral-blood-flow-during-preterm-brain-development-preliminary-assessment-with-pseudo-continuous-arterial-spin-labeled-perfusion-mri
#19
Minhui Ouyang, Peiying Liu, Tina Jeon, Lina Chalak, Roy Heyne, Nancy K Rollins, Daniel J Licht, John A Detre, Timothy P L Roberts, Hanzhang Lu, Hao Huang
The human brain develops rapidly during 32-45 postmenstrual weeks (PMW), a critical stage characterized by dramatic increases of metabolic demand. The increasing metabolic demand can be inferred through measurements of regional cerebral blood flow (CBF), which might be coupled to regional metabolism in preterm brains. Arterial spin labeled (ASL) perfusion MRI is one of the few viable approaches for imaging regional CBF of preterm brains, but must be optimized for the extremely slow blood velocity unique in preterm brains...
February 15, 2017: NeuroImage
https://www.readbyqxmd.com/read/27986990/multiparametric-computer-aided-differential-diagnosis-of-alzheimer-s-disease-and-frontotemporal-dementia-using-structural-and-advanced-mri
#20
Esther E Bron, Marion Smits, Janne M Papma, Rebecca M E Steketee, Rozanna Meijboom, Marius de Groot, John C van Swieten, Wiro J Niessen, Stefan Klein
OBJECTIVES: To investigate the added diagnostic value of arterial spin labelling (ASL) and diffusion tensor imaging (DTI) to structural MRI for computer-aided classification of Alzheimer's disease (AD), frontotemporal dementia (FTD), and controls. METHODS: This retrospective study used MRI data from 24 early-onset AD and 33 early-onset FTD patients and 34 controls (CN). Classification was based on voxel-wise feature maps derived from structural MRI, ASL, and DTI...
December 16, 2016: European Radiology
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