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Diffusion imaging

P D Tar, N A Thacker, M Babur, Y Watson, S Cheung, R A Little, R G Gieling, K J Williams, J P B O'Connor
Motivation: Imaging demonstrates that preclinical and human tumors are heterogeneous, i.e. a single tumor can exhibit multiple regions that behave differently during both normal development and also in response to treatment. The large variations observed in control group tumors can obscure detection of significant therapeutic effects due to the ambiguity in attributing causes of change. This can hinder development of effective therapies due to limitations in experimental design, rather than due to therapeutic failure...
March 14, 2018: Bioinformatics
Oriol Blázquez, Gemma Martín, Ivan Camps, Antonio Mariscal, Julian López-Vidrier, Joan Manel Ramirez, Sergi Hernández, Sonia Estrade, Francesca Peiro, Rosalía Serna, Blas Garrido
The resistive switching properties of silicon-aluminium oxynitride (SiAlON) based devices have been studied. Electrical transport mechanisms at both resistance states were determined, exhibiting an ohmic behaviour at low resistant state and a defect-related Poole-Frenkel mechanism at high resistant state. Nevertheless, some features on the Al top-electrode are generated during the initial electroforming, suggesting some material modifications. An in-depth microscopic study at the nanoscale have been performed after the electroforming process, by acquiring scanning electron microscopy and transmission electron microscopy images...
March 16, 2018: Nanotechnology
Da Li, Yu-Ming Jiao, Liang Wang, Fu-Xin Lin, Jun Wu, Xian-Zeng Tong, Shuo Wang, Yong Cao
OBJECTIVE Surgical management of brainstem lesions is challenging due to the highly compact, eloquent anatomy of the brainstem. This study aimed to evaluate the safety and efficacy of preoperative diffusion tensor imaging (DTI) and diffusion tensor tractography (DTT) in brainstem cavernous malformations (CMs). METHODS A prospective randomized controlled clinical trial was performed by using stratified blocked randomization. The primary eligibility criterion of the study was being a surgical candidate for brainstem CMs (with informed consent)...
March 16, 2018: Journal of Neurosurgery
Luke Gerges, Dorota Popiolek, Andrew B Rosenkrantz
OBJECTIVE: The purpose of this study is to assess the utility of texture analysis of multiple MRI sequences for the differentiation of uterine leiomyomas and leiomyosarcomas. MATERIALS AND METHODS: Seventeen leiomyosarcomas and 51 leiomyomas undergoing MRI before resection were included. Whole-lesion volumes of interest were placed on T2-weighted images, contrast-enhanced T1-weighted images, and apparent diffusion coefficient (ADC) maps. The diagnostic performance of histogram metrics was assessed...
March 16, 2018: AJR. American Journal of Roentgenology
Elizabeth Hernandez, Raymond Rowan, Martina Randall
Primary bone lymphoma is a rare disease, accounting for less than 5% of all extranodal lymphoma. Although the femur is cited as being the most common site, primary bone lymphoma is rare, accounting for less than 1% of all non-Hodgkin's lymphoma. Herein we present a case of diffuse B-cell-type malignant lymphoma manifested as a large soft-tissue mass of the leg, via metastasis of primary non-Hodgkin's lymphoma of the femur, which went untreated. We highlight the advantages of various imaging modalities used throughout the process of diagnosis and treatment because accurate and early diagnosis are essential...
January 2018: Journal of the American Podiatric Medical Association
Xiao-Ling Yang, Yolandi van der Merwe, Jeffrey Sims, Carlos Parra, Leon C Ho, Joel S Schuman, Gadi Wollstein, Kira L Lathrop, Kevin C Chan
Although elevated intraocular pressure (IOP) and age are major risk factors for glaucoma, their effects on glaucoma pathogenesis remain unclear. This study examined the onset and progression of glaucomatous changes to ocular anatomy and physiology, structural and physiological brain integrity, and visuomotor behavior in the DBA/2J mice via non-invasive tonometry, multi-parametric magnetic resonance imaging (MRI) and optokinetic assessments from 5 to 12 months of age. Using T2-weighted MRI, diffusion tensor MRI, and manganese-enhanced MRI, increasing IOP elevation at 9 and 12 months old coincided with anterior chamber deepening, altered fractional anisotropy and radial diffusivity of the optic nerve and optic tract, as well as reduced anterograde manganese transport along the visual pathway respectively in the DBA/2J mice...
March 15, 2018: Scientific Reports
D Mata-Mbemba, M Zapotocky, S Laughlin, M D Taylor, V Ramaswamy, C Raybaud
BACKGROUND AND PURPOSE: Molecular grouping of medulloblastoma correlates with prognosis and supports the therapeutic strategy. We provide our experience with the imaging features of primary and metastatic disease in relation to the molecular groups. MATERIALS AND METHODS: One hundred nineteen consecutive patients (mean age, 7.3 ± 3.8 years at diagnosis; male, 79 [66.4%]) with a confirmed diagnosis of medulloblastoma and interpretable pretreatment MRIs were retrieved from our data base from January 2000 to December 2016...
March 15, 2018: AJNR. American Journal of Neuroradiology
Naoki Ohno, Tosiaki Miyati, Shuto Suzuki, Hirohito Kan, Toshitaka Aoki, Yoshitaka Nakamura, Yuki Hiramatsu, Satoshi Kobayashi, Toshifumi Gabata
PURPOSE: To suppress olefinic signals and enable simultaneous and quantitative estimation of multiple functional parameters associated with water and lipid, we investigated a modified method using chemical shift displacement and recovery-based separation of lipid tissue (SPLIT) involving acquisitions with different inversion times (TIs), echo times (TEs), and b-values. MATERIALS AND METHODS: Single-shot diffusion echo-planar imaging (SSD-EPI) with multiple b-values (0-3000 s/mm2 ) was performed without fat suppression to separate water and lipid images using the chemical shift displacement of lipid signals in the phase-encoding direction...
March 12, 2018: Magnetic Resonance Imaging
Shotaro Kanao, Masako Kataoka, Mami Iima, Debra Masako Ikeda, Masakazu Toi, Kaori Togashi
OBJECTIVES: Benign and malignant inflammatory breast lesions demonstrate similar findings on both T2 weighted imaging (T2WI) and dynamic contrast enhanced (DCE) images. We hypothesized that benign inflammatory lesions might be differentiated form malignancies using a combination of apparent diffusion coefficient (ADC) values derived from diffusion weighted images (DWI) and T2WI. MATERIALS AND METHODS: We retrospectively reviewed 162 patients undergoing breast MRI (T2WI, DWI and DCE images) between 2008 and 2015 who had breast lesions with high T2WI signal intensity (High T2 SI) including 14 benign inflammatory lesions, 69 benign non-inflammatory lesions, 16 malignant inflammatory lesions and 63 malignant non-inflammatory lesions...
March 12, 2018: Magnetic Resonance Imaging
Heather T Whittaker, Shenghua Zhu, Domenico L Di Curzio, Richard Buist, Xin-Min Li, Suzanna Noy, Frances K Wiseman, Jonathan D Thiessen, Melanie Martin
Alzheimer's disease (AD) pathology causes microstructural changes in the brain. These changes, if quantified with magnetic resonance imaging (MRI), could be studied for use as an early biomarker for AD. The aim of our study was to determine if T1 relaxation, diffusion tensor imaging (DTI), and quantitative magnetization transfer imaging (qMTI) metrics could reveal changes within the hippocampus and surrounding white matter structures in ex vivo transgenic mouse brains overexpressing human amyloid precursor protein with the Swedish mutation...
March 12, 2018: Magnetic Resonance Imaging
Dmitry S Novikov, Jelle Veraart, Ileana O Jelescu, Els Fieremans
We develop a general analytical and numerical framework for estimating intra- and extra-neurite water fractions and diffusion coefficients, as well as neurite orientational dispersion, in each imaging voxel. By employing a set of rotational invariants and their expansion in the powers of diffusion weighting, we analytically uncover the nontrivial topology of the parameter estimation landscape, showing that multiple branches of parameters describe the measurement almost equally well, with only one of them corresponding to the biophysical reality...
March 12, 2018: NeuroImage
Dae-Hyun Kim, Deok-Soo Lee, Hyun-Wook Nah, Jae-Kwan Cha
BACKGROUND: A significant proportion of patients with mild ischemic stroke become disabled despite receiving intravenous thrombolytic therapy. The purpose of this study was to assess the clinical and radiological factors associated with unfavorable outcomes in patients with minor ischemic stroke that received intravenous recombinant tissue plasminogen activator (rt-PA) therapy. METHODS: We identified anterior circulation stroke patients with initial National Institutes of Health Stroke Scale (NIHSS) scores ≤5 who received intravenous thrombolysis within 4...
March 15, 2018: BMC Neurology
Katsuyuki Taguchi, Toshihide Itoh, Matthew K Fuld, Eric Fournie, Okkyun Lee, Kyo Noguchi
OBJECTIVES: A novel imaging technique ("X-map") has been developed to identify acute ischemic lesions for stroke patients using non-contrast-enhanced dual-energy computed tomography (NE-DE-CT). Using the 3-material decomposition technique, the original X-map ("X-map 1.0") eliminates fat and bone from the images, suppresses the gray matter (GM)-white matter (WM) tissue contrast, and makes signals of edema induced by severe ischemia easier to detect. The aim of this study was to address the following 2 problems with the X-map 1...
March 14, 2018: Investigative Radiology
Evgeny J Chumin, Joaquín Goñi, Meredith E Halcomb, Timothy C Durazzo, Mario Džemidžić, Karmen K Yoder
BACKGROUND: Diffusion weighted imaging (DWI) has been widely used to investigate the integrity of white matter (WM; indexed by fractional anisotropy, FA) in alcohol dependence and cigarette smoking. These disorders are highly comorbid, yet cigarette use has often not been adequately controlled in neuroimaging studies of alcohol dependent populations. In addition, information on white matter deficits in currently drinking, nontreatment-seeking (NTS) individuals with alcohol dependence is limited...
March 15, 2018: Alcoholism, Clinical and Experimental Research
E V Aleksandrova, A I Batalov, E L Pogosbekyan, N E Zakharova, L M Fadeeva, A D Kravchuk, I N Pronin, A A Potapov
The study purpose was to develop a technique for intravital visualization of the brainstem reticular formation fibers in healthy volunteers using magnetic resonance imaging (MRI). MATERIAL AND METHODS: The study included 21 subjects (13 males and 8 females) aged 21 to 62 years. The study was performed on a magnetic resonance imaging scanner with a magnetic field strength of 3 T in T1, T2, T2-FLAIR, DWI, and SWI modes. A CSD-HARDI algorithm was used to identify thin intersecting fibers of the reticular formatio...
2018: Zhurnal Voprosy Neĭrokhirurgii Imeni N. N. Burdenko
Carlos Garcia-Esperon, Andrew Bivard, Christopher Levi, Mark Parsons
Background Computed tomography perfusion is becoming widely accepted and used in acute stroke treatment. Computed tomography perfusion provides pathophysiological information needed in the acute decision making. Moreover, computed tomography perfusion shows excellent correlation with diffusion-weighted imaging and perfusion-weighted sequences to evaluate core and penumbra volumes. Multimodal computed tomography perfusion has practical advantages over magnetic resonance imaging, including availability, accessibility, and speed...
January 1, 2018: International Journal of Stroke: Official Journal of the International Stroke Society
Piotr Sowa, Hanne F Harbo, Nathan S White, Elisabeth G Celius, Hauke Bartsch, Pål Berg-Hansen, Stine M Moen, Atle Bjørnerud, Lars T Westlye, Ole A Andreassen, Anders M Dale, Mona K Beyer
BACKGROUND: Restriction spectrum imaging (RSI) is a recently introduced magnetic resonance imaging diffusion technique. The utility of RSI in multiple sclerosis (MS) is unknown. OBJECTIVE: To investigate the association between RSI-derived parameters and neurological disability in MS. METHODS: Seventy-seven relapsing-remitting MS patients were scanned with RSI on a 3-T scanner. RSI-derived parameters: fast and slow apparent diffusion coefficient (sADC), fractional anisotropy, restricted fractional anisotropy, neurite density (ND), cellularity, extracellular water fraction, and free water fraction, were obtained in white matter lesions (WML) and normal appearing white matter (NAWM)...
March 1, 2018: Multiple Sclerosis: Clinical and Laboratory Research
Eliott Teston, Thomas Maldiney, Iris Marangon, Jeanne Volatron, Yoann Lalatonne, Laurence Motte, Catherine Boisson-Vidal, Gwennhael Autret, Olivier Clément, Daniel Scherman, Florence Gazeau, Cyrille Richard
Once injected into a living organism, cells diffuse or migrate around the initial injection point and become impossible to be visualized and tracked in vivo. The present work concerns the development of a new technique for therapeutic cell labeling and subsequent in vivo visualization and magnetic retention. It is hypothesized and subsequently demonstrated that nanohybrids made of persistent luminescence nanoparticles and ultrasmall superparamagnetic iron oxide nanoparticles incorporated into a silica matrix can be used as an effective nanoplatform to label therapeutic cells in a nontoxic way in order to dynamically track them in real-time in vitro and in living mice...
March 15, 2018: Small
Farzaneh Ghazi Sherbaf, Mahtab Mojtahed Zadeh, Maryam Haghshomar, Mohammad Hadi Aarabi
Psychiatric symptoms and motor impairment are major contributions to the poor quality of life in patients with Parkinson's disease (PD). Here, we applied a novel diffusion-weighted imaging approach, diffusion MRI connectometry, to investigate the correlation of quality of life, evaluated by Parkinson's Disease Questionnaire (PDQ39) with the white matter structural connectivity in 27 non-demented PD patients (disease duration of 5.3 ± 2.9 years, H and Y stage = 1.5 ± 0.6, UPDRS-III = 13.7 ± 6.5, indicating unilateral and mild motor involvement)...
March 14, 2018: Acta Neurologica Belgica
Manijeh Beigi, Kevan Ghasemi, Parvin Mirzaghavami, Mohammadreza Khanmohammadi, Hamidreza SalighehRad
The main aim of this study was to propose a new statistical method for evaluation of spatial malignancy distribution within Magnetic Resonance Spectroscopy (MRS) grid in Glioblastoma Multiforme patients. Voxels with different malignancy probabilities were presented as a novel MRS-based Malignancy Probability Map (MPM). For this purpose, a predictive probability-based clustering approach was developed, including the two following steps: (1) Gaussian Mixture Model, (2) Quadratic Discriminate Analysis coupled with Genetic Algorithm...
March 14, 2018: Journal of Neuro-oncology
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