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Functional magnetic resonance imaging

Ashley A Yttredahl, Erin McRobert, Benjamin Sheler, Brian J Mickey, Tiffany M Love, Scott A Langenecker, Jon-Kar Zubieta, David T Hsu
INTRODUCTION: Responding adaptively to one's social environment is a key factor predicting the course of major depressive disorder (MDD). Socially rejecting events can exacerbate, whereas socially accepting events can ameliorate depressive symptoms. The neural responses to rejection and acceptance in MDD are relatively unexplored. METHODS: We used functional magnetic resonance imaging (fMRI) to measure neural responses to romantic rejection and acceptance in women diagnosed with current MDD (n = 19) and a matched group of healthy controls (HCs) (n = 19)...
February 27, 2018: Journal of Affective Disorders
Shelley HuaLei Zhang, Stephan E Maier, Lawrence P Panych
PURPOSE: Magnetic resonance spectroscopic imaging (MRSI), under low-spatial resolution settings, often suffers signal contamination from neighboring voxels due to ringing artifacts. Spatial localization can be improved by constraining the point-spread-function (PSF). Here the effectiveness of the two-dimensional PSF-Choice technique in providing improved spatial localization for MRSI is demonstrated. THEORY AND METHODS: The PSF-Choice technique constrains the PSF to a desired shape by manipulating the weighting of RF excitation pulse throughout phase-encode steps...
March 3, 2018: Journal of Magnetic Resonance
Radosław Mrówczyński, Artur Jędrzak, Kosma Szutkowski, Bartosz F Grześkowiak, Emerson Coy, Roksana Markiewicz, Teofil Jesionowski, Stefan Jurga
Polydopamine (PDA)-coated magnetic nanoparticles functionalized with mono-6-thio-β-cyclodextrin (SH-βCD) were obtained and characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Nuclear and Magnetic Resonance Imaging (NMR and MRI), and doxorubicin (DOXO)-loading experiments. The liver cancer cellular internalization of DOXO-loaded nanoparticles was investigated by confocal imaging microscopy. Synthesized nanomaterials bearing a chemotherapeutic drug and a layer of polydopamine capable of absorbing near-infrared light show high performance in the combined chemo- and photothermal therapy (CT-PTT) of liver cancer due to the synergistic effect of both modalities as demonstrated in vitro...
March 16, 2018: Nanomaterials
Hesham Mostafa Zakaria, Peter Joseph Massa, Richard L Smith, Tarek Hazem Moharram, John Corrigan, Ian Lee, Lonni Schultz, Jianhui Hu, Suresh Patel, Brent Griffith
Preoperative identification of the eloquent brain is important for neurosurgical planning. One common method of finding the motor cortex is by localizing "the Omega sign." No studies have tested the reliability of imaging to identify the Omega sign. We identified 40 recent and consecutive patients who had undergone preoperative functional magnetic resonance imaging for identification of the hand motor area prior to tumor resection. We recruited 11 neurosurgical residents of various levels of training and one board-certified neurosurgeon to identify the hand motor cortex Omega...
January 1, 2018: Neuroradiology Journal
Filip Čtvrtlík, Pavel Koranda, Jan Schovánek, Jozef Škarda, Igor Hartmann, Zbyněk Tüdös
The topic of pheochromocytomas is becoming increasingly popular as a result of major advances in different medical fields, including laboratory diagnosis, genetics, therapy, and particularly in novel advances in imaging techniques. The present review article discusses current clinical, biochemical, genetic and histopathological aspects of the diagnosis of pheochromocytomas and planning of pre-surgical preparation and subsequent surgical treatment options. The main part of the paper is focused on the role of morphological imaging methods (primarily computed tomography and magnetic resonance imaging) and functional imaging (scintigraphy and positron emission tomography) in the diagnosis and staging of pheochromocytomas...
April 2018: Experimental and Therapeutic Medicine
Rupesh K Chikara, Erik C Chang, Yi-Chen Lu, Dar-Shong Lin, Chin-Teng Lin, Li-Wei Ko
A reward or punishment can modulate motivation and emotions, which in turn affect cognitive processing. The present simultaneous functional magnetic resonance imaging-electroencephalography study examines neural mechanisms of response inhibition under the influence of a monetary reward or punishment by implementing a modified stop-signal task in a virtual battlefield scenario. The participants were instructed to play as snipers who open fire at a terrorist target but withhold shooting in the presence of a hostage...
2018: Frontiers in Human Neuroscience
Jiayu Chen, Barnaly Rashid, Qingbao Yu, Jingyu Liu, Dongdong Lin, Yuhui Du, Jing Sui, Vince D Calhoun
Imaging genetics posits a valuable strategy for elucidating genetic influences on brain abnormalities in psychiatric disorders. However, association analysis between 2D genetic data (subject × genetic variable) and 3D first-level functional magnetic resonance imaging (fMRI) data (subject × voxel × time) has been challenging given the asymmetry in data dimension. A summary feature needs to be derived for the imaging modality to compute inter-modality association at subject level. In this work, we propose to use variability in resting state networks (RSNs) and functional network connectivity (FNC) as potential features for purpose of association analysis...
2018: Frontiers in Neuroscience
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
Shelby Meier, Assaf A Gilad, J Anthony Brandon, Chenghao Qian, Erhe Gao, Jose F Abisambra, Moriel Vandsburger
Research into gene therapy for heart failure has gained renewed interest as a result of improved safety and availability of adeno-associated viral vectors (AAV). While magnetic resonance imaging (MRI) is standard for functional assessment of gene therapy outcomes, quantitation of gene transfer/expression relies upon tissue biopsy, fluorescence or nuclear imaging. Imaging of gene expression through the use of genetically encoded chemical exchange saturation transfer (CEST)-MRI reporter genes could be combined with clinical cardiac MRI methods to comprehensively probe therapeutic gene expression and subsequent outcomes...
March 15, 2018: Scientific Reports
T Labbé Atenas, E Ciampi Díaz, J P Cruz Quiroga, S Uribe Arancibia, C Cárcamo Rodríguez
Functional magnetic resonance imaging (fMRI) is an advanced tool for the study of brain functions in healthy subjects and in neuropsychiatric patients. This tool makes it possible to identify and locate specific phenomena related to neuronal metabolism and activity. Starting with the detection of changes in the blood supply to a region that participates in a function, more complex approaches have been developed to study the dynamics of neuronal networks. Studies examining the brain at rest or involved in different tasks have provided evidence related to the onset, development, and/or response to treatment in various diseases...
March 12, 2018: Radiología
Qihong Zou, Shuqin Zhou, Jing Xu, Zihui Su, Yuezhen Li, Yundong Ma, Hongqiang Sun, Changwei W Wu, Jia-Hong Gao
Rapid eye movement (REM) sleep has been frequently associated with dreaming. However, mounting evidence obtained from behavioral, pharmacological, and brain imaging studies suggests that REM sleep is not indicative of the dream report and may originate from diverse neural substrates in brain functionality. The aim of the current study was to investigate the functional systems associated with inter-individual differences in dream recall and REM sleep through assessments of the resting-state functional connectivity...
March 12, 2018: NeuroImage
Eli Gibson, Wenqi Li, Carole Sudre, Lucas Fidon, Dzhoshkun I Shakir, Guotai Wang, Zach Eaton-Rosen, Robert Gray, Tom Doel, Yipeng Hu, Tom Whyntie, Parashkev Nachev, Marc Modat, Dean C Barratt, Sébastien Ourselin, M Jorge Cardoso, Tom Vercauteren
BACKGROUND AND OBJECTIVES: Medical image analysis and computer-assisted intervention problems are increasingly being addressed with deep-learning-based solutions. Established deep-learning platforms are flexible but do not provide specific functionality for medical image analysis and adapting them for this domain of application requires substantial implementation effort. Consequently, there has been substantial duplication of effort and incompatible infrastructure developed across many research groups...
May 2018: Computer Methods and Programs in Biomedicine
Yoonjin Nah, Na-Young Shin, Sehjung Yi, Seung-Koo Lee, Sanghoon Han
Numerous studies have suggested that postpartum women show a decline in cognitive abilities. However, to date, no study has investigated the presence of qualitative alterations in recognition memory processes in postpartum women that may lead to a decline in cognitive ability. To address this issue, we employed the Remember/Know procedure and functional magnetic resonance imaging (fMRI). Behavioral results demonstrated that compared with the matched control (CTRL) group, the postpartum (PP) group endorsed "Remember" less and "Know" more to old items...
March 12, 2018: Neurobiology of Learning and Memory
Daniel M Stout, Daniel E Glenn, Dean T Acheson, Andrea D Spadoni, Victoria B Risbrough, Alan N Simmons
Contextual threat learning reflects two often competing processes: configural and elemental learning. Configural threat learning is a hippocampal-dependent process of forming a conjunctive representation of a context through binding of several multi-modal elements. In contrast, elemental threat-learning is governed by the amygdala and involves forming associative relationships between individual features within the context. Contextual learning tasks in humans however, rarely probe if a learned fear response is truly due to configural learning vs...
March 12, 2018: Neurobiology of Learning and Memory
Jeroen Gielen, Wietse Wiels, Jeroen Van Schependom, Jorne Laton, Wim Van Hecke, Paul M Parizel, Marie Beatrice D'hooghe, Guy Nagels
INTRODUCTION: The paced serial addition test (PSAT) is regularly used to assess cognitive deficits in various neuropsychiatric conditions. Being a complex test, it reflects the status of multiple cognitive domains such as working memory, information processing speed and executive functioning. Two versions of the PSAT exist. One uses auditory stimuli through spoken numbers and is known as the PASAT, while the other one presents patients with visual stimuli and is called PVSAT. The PASAT is considered more frustrating by patients, and hence the visual version is usually preferred...
2018: PloS One
Mario Fleischer, Alexander Mainka, Steffen Kürbis, Peter Birkholz
Recently, 3D printing has been increasingly used to create physical models of the vocal tract with geometries obtained from magnetic resonance imaging. These printed models allow measuring the vocal tract transfer function, which is not reliably possible in vivo for the vocal tract of living humans. The transfer functions enable the detailed examination of the acoustic effects of specific articulatory strategies in speaking and singing, and the validation of acoustic plane-wave models for realistic vocal tract geometries in articulatory speech synthesis...
2018: PloS One
Rajani Singh, Rajnish Arora, Raj Kumar
Chiari malformations (CMs) are variant structural setup of cerebellum and brain stem at the craniovertebral junction. Normally the cerebellum and parts of the brain stem lie above the foramen magnum. When the part of the cerebellum and/or brainstem protrudes into the upper spinal canal through foramen magnum, it is defined as CM. Chiari malformations may develop when part of the skull is smaller than normal or misshapen, due to which the cerebellum herniates into spinal canal through foramen magnum. This compresses the cerebellum and brainstem affecting functions controlled by these parts and blocks the flow of cerebrospinal fluid that surrounds and cushions the brain and spinal cord...
March 14, 2018: Journal of Craniofacial Surgery
Heather M Young, Fumin Guo, Rachel L Eddy, Geoffrey Maksym, Grace Parraga
Ventilation heterogeneity is a hallmark finding in obstructive lung disease and may be evaluated using a variety of methods including multiple-breath gas-washout and pulmonary imaging. Such methods provide an opportunity to better understand the relationships between structural and functional abnormalities in the lungs, and their relationships with important clinical outcomes. We measured ventilation heterogeneity and respiratory impedance in 100 subjects (50 asthmatics, 22 ex-smokers and 28 COPD), using oscillometry and hyperpolarized3 He magnetic resonance imaging (MRI) and determined their relationships with quality-of-life scores and disease control/exacerbations...
March 15, 2018: Journal of Applied Physiology
Lotte F van Dillen, Henk van Steenbergen
The present research examined whether cognitive load modulates the neural processing of appetitive, high-calorie food stimuli. In a functional magnetic resonance imaging (fMRI) study, participants quickly categorized high-calorie and low-calorie food pictures versus object pictures as edible or inedible while they concurrently performed a digit-span task that varied between low and high cognitive load (memorizing six digits vs. one digit). In line with predictions, the digit-span task engaged the dorsolateral prefrontal cortex (DLPFC) when cognitive load was high compared to low...
March 14, 2018: Cognitive, Affective & Behavioral Neuroscience
C T Bahadir, G C Ecemis, H Atmaca
PURPOSE: The aim of this study was to investigate the possible association of insulin-like growth factor-1 (IGF-1) with the pathogenesis of non-functioning adrenocortical adenomas (NFAs). METHODS: This study included 50 female patients (mean age 54 years) with NFAs, 55 patients (mean age 48 years; 20 male, 35 female) with acromegaly and 38 female control subjects (mean age 58 years). Body mass index (BMI) and waist circumference (WC) of the subjects were recorded and blood samples for IGF-1 were taken...
March 14, 2018: Journal of Endocrinological Investigation
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