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https://www.readbyqxmd.com/read/28325031/magnetic-resonance-imaging-receiver-coil-decoupling-using-circumferential-shielding-structures
#1
Jhy-Neng Tasso Yeh, Fa-Hsuan Lin
We propose a flexible phased-array design using circular coils with circumferential shielding structure to achieve robust decoupling between coil elements when the array is either bended or on a flat plane. Two types of circumferential shielding were tested through numerical simulation and imaging experiment. The results demonstrated that our arrays have good decoupling between coils when they are on a curved surface with S21 <; -16.72 dB. Both types perform higher SNR images than a commercially available 32-channel adult head coil array...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28325028/tracking-intrinsic-connectivity-brain-network-features-during-successive-pseudo-resting-states-and-interoceptive-task-fmri
#2
Behnaz Jarrahi, Dante Mantini
Advanced multivariate analyses of functional magnetic resonance imaging (fMRI) data based on blood oxygen level-dependent (BOLD) contras have revealed that the human brain organizes its activities into multiple intrinsic connectivity networks (ICNs). Several fMRI studies have evaluated the modulations of these networks during different cognitive or emotional tasks using blind source separation techniques particularly the independent component analysis (ICA). In this exploratory study, we applied ICA methodology to examine ICN modulations under different interoceptive conditions...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28325027/identifying-the-effects-of-visceral-interoception-on-human-brain-connectome-a-multivariate-analysis-of-covariance-of-fmri-data
#3
Behnaz Jarrahi, Dante Mantini
Sources of variations in the neural circuitry of the human brain and interrelationship between intrinsic connectivity networks (ICNs) are still a matter of debate and ongoing research. Here, we applied a multivariate analysis of covariance (MANCOVA) based on high-dimensional independent component analysis (ICA) to identify the effects of interoception and related variables on human brain connectome. Fifteen healthy right-handed subjects (all females, age range 21 - 48 years; mean age = 30.3, SD = 8.7 years) underwent a blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) that included continuous intravesical saline infusion and drainage...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28325001/reliability-of-a-cortical-surface-based-analysis-with-subcortical-regression-in-the-identification-of-resting-state-functional-networks
#4
R Lopes, P Besson, R Viard, C Bournonville, C Delmaire, X Leclerc
Many methods exist for identifying brain networks in resting-state functional magnetic resonance imaging. During the last decade, there was a growing interest in functional connectivity using surface-based analysis. However, the advantages of this approach against volume-based analysis in a data-driven model are unclear. In this study, we propose an independent component analysis based method to extract the resting-state networks directly on the cortical surface. The components associated with the subcortical regions are identified by multiple linear regressions between the signals in subcortical voxels and independent components time courses...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28324983/the-precuneus-may-encode-irrationality-in-human-gambling
#5
P Sacre, M S D Kerr, S Subramanian, K Kahn, J Gonzalez-Martinez, M A Johnson, S V Sarma, J T Gale
Humans often make irrational decisions, especially psychiatric patients who have dysfunctional cognitive and emotional circuitry. Understanding the neural basis of decision-making is therefore essential towards patient management, yet current studies suffer from several limitations. Functional magnetic resonance imaging (fMRI) studies in humans have dominated decision-making neuroscience, but have poor temporal resolution and the blood oxygenation level-dependent signal is only a proxy for neural activity. On the other hand, lesion studies in humans used to infer functionality in decision-making lack characterization of neural activity altogether...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28324965/high-dielectric-material-in-mri-numerical-assessment-of-the-reduction-of-the-induced-local-power-on-implanted-cardiac-leads
#6
Eugenio Mattei, Elena Lucano, Federica Censi, Leonardo M Angelone, Giovanni Calcagnini
High dielectric materials (HDM) have been proposed in magnetic resonance imaging (MRI) to increase the signal-to-noise ratio (SNR) of the images acquired while reducing the radiofrequency (RF) absorption in tissue. The aim of this study is to assess the potential merit of using HDM to reduce power induced at the tip of an endocardial lead in patients undergoing MRI. Numerical simulations were performed using a commercial finite-differences time-domain (FDTD) software to model the RF field generated by a birdcage body coil at 64 MHz on a human body model...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28324943/overcoming-spatio-temporal-limitations-using-dynamically-scaled-in-vitro-pc-mri-a-flow-field-comparison-to-true-scale-computer-simulations-of-idealized-stented-and-patient-specific-left-main-bifurcations
#7
Susann Beier, John Ormiston, Mark Webster, John Cater, Stuart Norris, Pau Medrano-Gracia, Alistair Young, Kathleen Gilbert, Brett Cowan
The majority of patients with angina or heart failure have coronary artery disease. Left main bifurcations are particularly susceptible to pathological narrowing. Flow is a major factor of atheroma development, but limitations in imaging technology such as spatio-temporal resolution, signal-to-noise ratio (SNRv), and imaging artefacts prevent in vivo investigations. Computational fluid dynamics (CFD) modelling is a common numerical approach to study flow, but it requires a cautious and rigorous application for meaningful results...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28324908/-magnetic-sentinel-lymph-node-detection-in-prostate-cancer-after-intraprostatic-injection-of-superparamagnetic-iron-oxide-nanoparticles
#8
Alexander Winter, Svenja Engels, Tobias Kowald, Tina Susanne Paulo, Holger Gerullis, Ajay Chavan, Friedhelm Wawroschek
In prostate cancer, reliable information about the lymph node status is of great importance for accurate staging and the optimal planning of treatment. Despite recent advances in imaging, the histological detection of metastases, or pelvic lymphadenectomy (PLND), continues to be the most reliable method for lymph node staging in clinically localised prostate cancer, especially as this procedure enables the detection of small or micrometastases. Radioisotope-guided sentinel PLND (sPLND) demonstrates high sensitivity in the detection of lymph node metastases as well as low morbidity in prostate cancer because of the targeted removal of a relatively small number of lymph nodes...
March 21, 2017: Aktuelle Urologie
https://www.readbyqxmd.com/read/28324849/oil-loving-hydrophobic-gels-made-from-glycerol-propoxylate-efficient-and-reusable-sorbents-for-oil-spill-clean-up
#9
Soner Kizil, Hayal Bulbul Sonmez
Glycerol propoxylate based oil loving sorbents were prepared through bulk polymerization, without using of an activator, initiator, or catalyst. Fourier transform infrared spectroscopy (FTIR), (13)C and (29)Si CPMAS nuclear magnetic resonance (NMR), as well as elemental analysis and thermal gravimetric analysis (TGA) were operated in order to identify the structural and thermal features of sorbents. The synthesized gels were employed as absorbents for various organic solvents and oils. The swelling capacity, absorption-desorption kinetics, reusability, and selective removal from an oil/water mixture were also examined...
March 15, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28324788/primary-central-nervous-system-vasculitis-and-its-mimicking-diseases-clinical-features-outcome-comorbidities-and-diagnostic-results-a-case-control-study
#10
J Becker, P A Horn, K Keyvani, I Metz, C Wegner, W Brück, F M Heinemann, J C Schwitalla, P Berlit, M Kraemer
OBJECTIVES: To compare clinical features and outcome, imaging characteristics, biopsy results and laboratory findings in a cohort of 69 patients with suspected or diagnosed primary central nervous system vasculitis (PCNSV) in adults; to identify risk factors and predictive features for PCNSV. PATIENTS AND METHODS: We performed a case-control-study including 69 patients referred with suspected PCNSV from whom 25 were confirmed by predetermined diagnostic criteria based on biopsy (72%) or angiography (28%)...
March 8, 2017: Clinical Neurology and Neurosurgery
https://www.readbyqxmd.com/read/28324693/cortical-complexity-in-bipolar-disorder-applying-a-spherical-harmonics-approach
#11
Igor Nenadic, Rachel A Yotter, Maren Dietzek, Kerstin Langbein, Heinrich Sauer, Christian Gaser
Recent studies using surface-based morphometry of structural magnetic resonance imaging data have suggested that some changes in bipolar disorder (BP) might be neurodevelopmental in origin. We applied a novel analysis of cortical complexity based on fractal dimensions in high-resolution structural MRI scans of 18 bipolar disorder patients and 26 healthy controls. Our region-of-interest based analysis revealed increases in fractal dimensions (in patients relative to controls) in left lateral orbitofrontal cortex and right precuneus, and decreases in right caudal middle frontal, entorhinal cortex, and right pars orbitalis, and left fusiform and posterior cingulate cortices...
February 21, 2017: Psychiatry Research
https://www.readbyqxmd.com/read/28324509/human-telomeric-g-quadruplex-structures-and-g-quadruplex-interactive-compounds
#12
Clement Lin, Danzhou Yang
G-quadruplexes are noncanonical secondary structures formed in DNA sequences containing consecutive runs of guanines. It has been shown that the 3' G-rich single-stranded overhangs of human telomeres can form G-quadruplex structures, and the human telomeric DNA G-quadruplexes are considered attractive targets for anticancer drugs. G-quadruplex-interactive compounds have been shown to inhibit telomerase access as well as telomere capping. Nuclear magnetic resonance (NMR) spectroscopy is a powerful method in determining the G-quadruplex structures under physiologically relevant conditions...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28324264/reverse-locked-in-syndrome
#13
Pooja Raibagkar, Ram V Chavali, Tamara B Kaplan, Jennifer A Kim, Meaghan V Nitka, Sherry H-Y Chou, Brian L Edlow
BACKGROUND: Basilar artery occlusion can cause locked-in syndrome, which is characterized by quadriplegia, anarthria, and limited communication via eye movements. Here, we describe an uncommon stroke syndrome associated with endovascular recanalization of the top of the basilar artery: "reverse locked-in syndrome." METHODS: We report the case of a patient with atypical neurological deficits caused by acute ischemic stroke of the midbrain tegmentum. We perform neuroanatomic localization of the patient's infarcts by mapping the magnetic resonance imaging (MRI) data onto a brainstem atlas...
March 21, 2017: Neurocritical Care
https://www.readbyqxmd.com/read/28324197/the-spectrum-of-magnetic-resonance-findings-in-cerebrotendinous-xanthomatosis-redefinition-and-evidence-of-new-markers-of-disease-progression
#14
Andrea Mignarri, Maria Teresa Dotti, Antonio Federico, Nicola De Stefano, Marco Battaglini, Irene Grazzini, Paolo Galluzzi, Lucia Monti
Cerebrotendinous xanthomatosis (CTX) is a metabolic disease characterized by systemic signs and neurological impairment, which can be prevented if chenodeoxycholic acid (CDCA) treatment is started early. Despite brain MRI represents an essential diagnostic tool, the spectrum of findings is worth to be reappraised, and follow-up data are needed. We performed clinical evaluation and brain MRI in 38 CTX patients. Sixteen of them who were untreated at baseline examination underwent clinical and MRI follow-up after long-term treatment with CDCA...
March 21, 2017: Journal of Neurology
https://www.readbyqxmd.com/read/28324157/water-fat-mri-in-a-hibernator-reveals-seasonal-growth-of-white-and-brown-adipose-tissue-without-cold-exposure
#15
Amanda MacCannell, Kevin Sinclair, Lannette Friesen-Waldner, Charles A McKenzie, James F Staples
Obligate hibernators, such as ground squirrels, display circannual patterns which persist even under constant laboratory conditions, suggesting that they are regulated by endogenous rhythms. Brown adipose tissue (BAT) is important for thermogenesis during periodic arousals from hibernation when core body temperature rises spontaneously from 5 to 37 °C. In most small eutherians BAT growth requires several weeks of cold exposure. We hypothesized that in the thirteen-lined ground squirrel (Ictidomys tridecemlineatus), a hibernator, BAT growth is regulated, in part, by an endogenous rhythm and we predicted that this growth would precede the hibernation season without cold exposure...
March 21, 2017: Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology
https://www.readbyqxmd.com/read/28324152/good-clinical-results-with-autologous-matrix-induced-chondrogenesis-amic-technique-in-large-knee-chondral-defects
#16
Alfredo Schiavone Panni, Chiara Del Regno, Giuseppe Mazzitelli, Rocco D'Apolito, Katia Corona, Michele Vasso
PURPOSE: Autologous matrix-induced chondrogenesis (AMIC) is a treatment for focal full-thickness cartilage defects combining microfracturing with an exogenous I/III collagen matrix (Chondro-Gide). The aim of the present study was to determine the 7 years outcomes of patients treated with the AMIC technique for knee chondral defects larger than 2 cm(2). The hypothesis was that the positive short-term outcomes achieved in the previous series would not deteriorate at a 7-year follow-up...
March 21, 2017: Knee Surgery, Sports Traumatology, Arthroscopy: Official Journal of the ESSKA
https://www.readbyqxmd.com/read/28324130/the-oblique-popliteal-ligament-an-anatomic-and-mri-investigation
#17
Mandy Hedderwick, Mark D Stringer, Liam McRedmond, Grant R Meikle, Stephanie J Woodley
PURPOSE: Despite being the largest ligament on the posterior aspect of the knee, relatively little is known about the normal morphology of the oblique popliteal ligament (OPL). The aim of this study was to investigate the detailed anatomy of the OPL in cadavers and healthy volunteers. METHODS: The posterior knee was investigated in 25 cadaver lower limbs (mean age 76 ± 9.5 years; 7 men) by dissection, histology, and serial plastination and in 14 healthy individuals (mean age 23 ± 3...
March 21, 2017: Surgical and Radiologic Anatomy: SRA
https://www.readbyqxmd.com/read/28324121/-impingement-syndrome-of-the-ankle
#18
R-I Milos, L B Fritz, C Schueller-Weidekamm
Impingement syndrome of the ankle is a clinical diagnosis caused posttraumatically by overuse due to repetitive mechanical loading or the presence of predisposing anatomical variants. Ankle impingement syndrome is characterized by chronic pain and limited range of movement caused by mechanical compression of bony or soft tissues within the joint compartments. Ankle impingement syndrome is classified according to the various anatomical locations around the tibiotalar joint as anterior, anterolateral, anteromedial, posterior or posteromedial...
March 21, 2017: Der Radiologe
https://www.readbyqxmd.com/read/28324118/early-onset-polymyalgia-rheumatica-two-rare-cases-under-age-of-50
#19
Jinyoung Park, Duk Hyun Sung
Polymyalgia rheumatica (PMR) is almost an exclusive disease of adults over the age of 50, and only a few cases have been reported. Two 46-year-old females visited our locomotor pain clinic with multiple joint pain with increased acute phase reactants. Rheumatologic markers, and HLA-B27 were checked. Serum protein electrophoresis and serum immunofixation electrophoresis, imaging studies including plane image, sonography, and magnetic resonance image was done. (18)F-Fludeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) showed characteristic findings of PMR, without evidences of sacroiliitis...
March 21, 2017: Skeletal Radiology
https://www.readbyqxmd.com/read/28324028/a-duodenal-sdh-deficient-gastrointestinal-stromal-tumor-in-a-patient-with-a-germline-sdhb-mutation
#20
M S Elston, S Sehgal, M Dray, E Phillips, J V Conaglen, R J Clifton-Bligh, A J Gill
Context: Gastrointestinal Stromal Tumors (GISTs) are mesenchymal tumors of the gastrointestinal tract arising from the interstitial cells of Cajal. Succinate dehydrogenase (SDH) deficient GISTs are a unique class of GIST defined by: loss of immunohistochemical expression of SDHB indicating dysfunction of the mitochondrial complex 2, lack of driver mutations in KIT and PDGFRA, and a distinctive morphology and natural history. To date, all reported SDH-deficient GISTs have arisen in the stomach...
March 15, 2017: Journal of Clinical Endocrinology and Metabolism
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