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https://www.readbyqxmd.com/read/28741597/motion-compensation-for-cone-beam-ct-using-fourier-consistency-conditions
#1
Martin Berger, Yan Xia, Wolfgang Aichinger, Katrin Mentl, Mathias Unberath, Andre Aichert, Christian Riess, Joachim Hornegger, Rebecca Fahrig, Andreas Konrad Maier
In cone-beam CT, involuntary patient motion and inaccurate or irreproducible scanner motion substantially degrades image quality. To avoid artifacts this motion needs to be estimated and compensated during image reconstruction. In previous work we showed that Fourier Consistency Conditions (FCC) can be used in fan-beam CT to estimate motion in the sinogram domain. This work extends the FCC to 3-D cone-beam CT. We derive an efficient cost function to compensate for 3-D motion using 2-D detector translations...
July 25, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28739527/deconstructing-the-cortical-column-in-the-barrel-cortex
#2
Kevin Fox
The question of what function is served by the cortical column has occupied neuroscientists since its original description some 60 years ago. The answer seems tractable in the somatosensory cortex when considering the inputs to the cortical column and the early stages of information processing, but quickly breaks down once the multiplicity of output streams and their sub-circuits are brought into consideration. This article describes the early stages of information processing in the barrel cortex, through generation of the centre and surround receptive field components of neurones that subserve integration of multi whisker information, before going on to consider the diversity of properties exhibited by the layer 5 output neurones...
July 21, 2017: Neuroscience
https://www.readbyqxmd.com/read/28737634/noise-reduction-to-reduce-patient-anxiety-during-cast-removal-can-we-decrease-patient-anxiety-with-cast-removal-by-wearing-noise-reduction-headphones-during-cast-saw-use
#3
Susan T Mahan, Marie S Harris, Anneliese M Lierhaus, Patricia E Miller, Rachel L DiFazio
BACKGROUND: Noise reduction headphones decrease the sound during cast removal. Their effectiveness in decreasing anxiety has not been studied. PURPOSE: Compare pediatric patients' anxiety levels during cast removal with and without utilization of noise reduction headphones combined with use of a personal electronic device. METHODS: Quality improvement project. Patients randomly assigned to noise reduction headphone group or standard care group during cast removal...
July 2017: Orthopaedic Nursing
https://www.readbyqxmd.com/read/28736736/feedback-driven-sensory-mapping-adaptation-for-robust-speech-activity-detection
#4
Ashwin Bellur, Mounya Elhilali
Parsing natural acoustic scenes using computational methodologies poses many challenges. Given the rich and complex nature of the acoustic environment, data mismatch between train and test conditions is a major hurdle in data-driven audio processing systems. In contrast, the brain exhibits a remarkable ability at segmenting acoustic scenes with relative ease. When tackling challenging listening conditions that are often faced in everyday life, the biological system relies on a number of principles that allow it to effortlessly parse its rich soundscape...
March 2017: IEEE/ACM Transactions on Audio, Speech, and Language Processing
https://www.readbyqxmd.com/read/28736698/impact-of-automated-ica-based-denoising-of-fmri-data-in-acute-stroke-patients
#5
D Carone, R Licenik, S Suri, L Griffanti, N Filippini, J Kennedy
Different strategies have been developed using Independent Component Analysis (ICA) to automatically de-noise fMRI data, either focusing on removing only certain components (e.g. motion-ICA-AROMA, Pruim et al., 2015a) or using more complex classifiers to remove multiple types of noise components (e.g. FIX, Salimi-Khorshidi et al., 2014 Griffanti et al., 2014). However, denoising data obtained in an acute setting might prove challenging: the presence of multiple noise sources may not allow focused strategies to clean the data enough and the heterogeneity in the data may be so great to critically undermine complex approaches...
2017: NeuroImage: Clinical
https://www.readbyqxmd.com/read/28734531/event-based-control-of-depth-of-hypnosis-in-anesthesia
#6
Luca Merigo, Manuel Beschi, Fabrizio Padula, Nicola Latronico, Massimiliano Paltenghi, Antonio Visioli
BACKGROUND AND OBJECTIVE: In this paper, we propose the use of an event-based control strategy for the closed-loop control of the depth of hypnosis in anesthesia by using propofol administration and the bispectral index as a controlled variable. METHODS: A new event generator with high noise-filtering properties is employed in addition to a PIDPlus controller. The tuning of the parameters is performed off-line by using genetic algorithms by considering a given data set of patients...
August 2017: Computer Methods and Programs in Biomedicine
https://www.readbyqxmd.com/read/28733918/feasibility-of-optimized-ultralow-dose-pulsed-fluoroscopy-for-upper-gastrointestinal-tract-examinations-a-phantom-study-with-clinical-correlation
#7
Jakob Weiss, Andreas Pomschar, Carsten Rist, Klement Neumaier, Minglun Li, Wilhelm Flatz, Kolja Thierfelder, Mike Notohamiprodjo
PURPOSE: To establish an optimized ultralow-dose digital pulsed fluoroscopy (FP) protocol for upper gastrointestinal tract examinations and to investigate the radiation dose and image quality. MATERIALS AND METHODS: An Alderson-Rando-Phantom with 60 thermoluminescent dosimeters was used for dose measurements to systematically evaluate the dose-area product (DAP) and organ doses of the optimized FP protocol with the following acquisition parameters: 86.7 kV; 77 mA; 0...
July 22, 2017: La Radiologia Medica
https://www.readbyqxmd.com/read/28727850/hybrid-cubature-kalman-filtering-for-identifying-nonlinear-models-from-sampled-recording-estimation-of-neuronal-dynamics
#8
Mahmoud K Madi, Fadi N Karameh
Kalman filtering methods have long been regarded as efficient adaptive Bayesian techniques for estimating hidden states in models of linear dynamical systems under Gaussian uncertainty. Recent advents of the Cubature Kalman filter (CKF) have extended this efficient estimation property to nonlinear systems, and also to hybrid nonlinear problems where by the processes are continuous and the observations are discrete (continuous-discrete CD-CKF). Employing CKF techniques, therefore, carries high promise for modeling many biological phenomena where the underlying processes exhibit inherently nonlinear, continuous, and noisy dynamics and the associated measurements are uncertain and time-sampled...
2017: PloS One
https://www.readbyqxmd.com/read/28724866/effect-of-reduced-tube-voltage-on-diagnostic-accuracy-of-ct-colonography
#9
Yoshihiro Futamata, Tomoaki Koide, Riku Ihara
The normal tube voltage in computed tomography colonography (CTC) is 120 kV. Some reports indicate that the use of a low tube voltage (lower than 120 kV) technique plays a significant role in reduction of radiation dose. However, to determine whether a lower tube voltage can reduce radiation dose without compromising diagnostic accuracy, an evaluation of images that are obtained while maintaining the volume CT dose index (CTDIvol) is required. This study investigated the effect of reduced tube voltage in CTC, without modifying radiation dose (i...
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/28718710/compressed-air-noise-reductions-from-using-advanced-air-gun-nozzles-in-research-and-development-environments
#10
Kurt Prieve, Amanda Rice, Peter C Raynor
The aims of this study were to evaluate sound levels produced by compressed air guns in research and development (R&D) environments, replace conventional air gun models with advanced noise-reducing air nozzles, and measure changes in sound levels to assess the effectiveness of the advanced nozzles as engineering controls for noise. Ten different R&D manufacturing areas that used compressed air guns were identified and included in the study. A-weighted sound level and Z-weighted octave band measurements were taken simultaneously using a single instrument...
August 2017: Journal of Occupational and Environmental Hygiene
https://www.readbyqxmd.com/read/28716314/safety-and-efficacy-of-ebselen-for-the-prevention-of-noise-induced-hearing-loss-a-randomised-double-blind-placebo-controlled-phase-2-trial
#11
Jonathan Kil, Edward Lobarinas, Christopher Spankovich, Scott K Griffiths, Patrick J Antonelli, Eric D Lynch, Colleen G Le Prell
BACKGROUND: Noise-induced hearing loss is a leading cause of occupational and recreational injury and disease, and a major determinant of age-related hearing loss. No therapeutic agent has been approved for the prevention or treatment of this disorder. In animal models, glutathione peroxidase 1 (GPx1) activity is reduced after acute noise exposure. Ebselen, a novel GPx1 mimic, has been shown to reduce both temporary and permanent noise-induced hearing loss in preclinical studies. We assessed the safety and efficacy of ebselen for the prevention of noise-induced hearing loss in young adults in a phase 2 clinical trial...
July 14, 2017: Lancet
https://www.readbyqxmd.com/read/28714888/a-multiscale-approach-to-the-smart-deployment-of-micro-sensors-over-lightweight-structures
#12
Giovanni Capellari, Francesco Caimmi, Matteo Bruggi, Stefano Mariani
A topology optimization approach has been recently proposed to maximize the sensitivity to damage of measurements, collected through a network of sensors to be deployed over thin plates for structural health monitoring purposes. Within such a frame, damage is meant as a change in the structural health characterized by a reduction of relevant stiffness and load-carrying properties. The sensitivity to a damage of unknown amplitude and location is computed by comparing the response to the external actions of the healthy structure and of a set of auxiliary damaged structures, each one featuring reduced mechanical properties in a small region only...
July 15, 2017: Sensors
https://www.readbyqxmd.com/read/28714530/acoustic-changes-in-the-speech-of-children-with-cerebral-palsy-following-an-intensive-program-of-dysarthria-therapy
#13
Lindsay Pennington, Eftychia Lombardo, Nick Steen, Nick Miller
BACKGROUND: The speech intelligibility of children with dysarthria and cerebral palsy has been observed to increase following therapy focusing on respiration and phonation. AIMS: To determine if speech intelligibility change following intervention is associated with change in acoustic measures of voice. METHODS & PROCEDURES: We recorded 16 young people with cerebral palsy and dysarthria (nine girls; mean age 14 years, SD = 2; nine spastic type, two dyskinetic, four mixed; one Worster-Drought) producing speech in two conditions (single words, connected speech) twice before and twice after therapy focusing on respiration, phonation and rate...
July 17, 2017: International Journal of Language & Communication Disorders
https://www.readbyqxmd.com/read/28714458/a-graphical-approach-to-optimizing-variable-kernel-smoothing-parameters-for-improved-deformable-registration-of-ct-and-cone-beam-ct-images
#14
Vern Hart, Damon Burrow, X Allen Li
A systematic method is presented for determining optimal parameters in variable-kernel deformable image registration of cone beam CT and CT images, in order to improve accuracy and convergence for potential use in online adaptive radiotherapy. Assessed conditions included the noise constant (symmetric force demons), the kernel reduction rate, the kernel reduction percentage, and the kernel adjustment criteria. Four such parameters were tested in conjunction with reductions of 5, 10, 15, 20, 30, and 40%. Noise constants ranged from 1...
July 17, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28714120/partial-fourier-techniques-in-single-shot-cross-term-spatiotemporal-encoded-mri
#15
Zhiyong Zhang, Lucio Frydman
PURPOSE: Cross-term spatiotemporal encoding (xSPEN) is a single-shot approach with exceptional immunity to field heterogeneities, the images of which faithfully deliver 2D spatial distributions without requiring a priori information or using postacquisition corrections. xSPEN, however, suffers from signal-to-noise ratio penalties due to its non-Fourier nature and due to diffusion losses-especially when seeking high resolution. This study explores partial Fourier transform approaches that, acting along either the readout or the spatiotemporally encoded dimensions, reduce these penalties...
July 16, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28712944/a-fe3o4-au-basedpseudo-homogeneous-electrochemical-immunosensor-for-afp-measurement-using-afp-antibody-gnps-hrp-as-detection-probe
#16
Yulin Yuan, Shanshan Li, Yewei Xue, Jintao Liang, Lijie Cui, Qingbo Li, Sufang Zhou, Yong Huang, Guiyin Li, Yongxiang Zhao
In this study, a Fe3O4@Au-based pseudo-homogeneous electrochemical immunosensor was prepared for detection of alpha fetoprotein (AFP), a well-known hepatocellular carcinoma biomarker. The primary antibody (Ab1) was immobilized on Fe3O4@Au NPs as the capture probe. Horseradish peroxidase (HRP) and secondary antibody (Ab2) were conjugated on gold nanoparticles (GNPs) through electrostatic adsorption to form signal-amplifying labels. In the presence of AFP, a sandwich immunocomplex was formed via specific recognition of antigen-antibody in a Fe3O4@Au-basedpseudo-homogeneousreaction system...
July 13, 2017: Analytical Biochemistry
https://www.readbyqxmd.com/read/28712714/spinning-slithole-collimation-for-high-sensitivity-small-animal-spect-design-and-assessment-using-gate-simulation
#17
Hojjat Mahani, Gholamreza Raisali, Alireza Kamali-Asl, Mohammad Reza Ay
PURPOSE: While traditional collimations are widely used in preclinical SPECT imaging, they usually suffer from possessing a low system sensitivity leading to noisy images. In this study, we are aiming at introducing a novel collimator, the slithole, offering a superior resolution-sensitivity tradeoff for small animal SPECT. METHODS: The collimator was designed for a molecular SPECT scanner, the HiReSPECT. The slithole is a knife-edge narrow long aperture extended across long-axis of the camera's head...
July 13, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28711735/transcranial-magnetic-stimulation-of-early-visual-cortex-suppresses-conscious-representations-in-a-dichotomous-manner-without-gradually-decreasing-their-precision
#18
Mika Koivisto, Inari Harjuniemi, Henry Railo, Niina Salminen-Vaparanta, Antti Revonsuo
Transcranial magnetic stimulation (TMS) of early visual cortex can suppresses visual perception at early stages of processing. The suppression can be measured both with objective forced-choice tasks and with subjective ratings of visual awareness, but there is lack of objective evidence on how and whether the TMS influences the quality of representations. Does TMS decrease the precision of representations in graded manner, or does it lead to dichotomous, "all-or-nothing" suppression. We resolved this question by using a continuous measure of the perceptual error: the observers had to perceive the orientation of a target (Landort-C) and to adjust the orientation of a probe to match that of the target...
July 12, 2017: NeuroImage
https://www.readbyqxmd.com/read/28711622/prolonged-low-level-noise-induced-plasticity-in-the-peripheral-and-central-auditory-system-of-rats
#19
Adam M Sheppard, Guang-Di Chen, Senthilvelan Manohar, Dalian Ding, Bo-Hua Hu, Wei Sun, Jiwie Zhao, Richard Salvi
Prolonged low-level noise exposure alters loudness perception in humans, presumably by decreasing the gain of the central auditory system. Here we test the central gain hypothesis by measuring the acute and chronic physiologic changes at the level of the cochlea and inferior colliculus (IC) after a 75-dB SPL, 10-20-kHz noise exposure for 5weeks. The compound action potential (CAP) and summating potential (SP) were used to assess the functional status of the cochlea and 16 channel electrodes were used to measure the local field potentials (LFP) and multi-unit spike discharge rates (SDR) from the IC immediately after and one-week post-exposure...
July 13, 2017: Neuroscience
https://www.readbyqxmd.com/read/28711208/applications-of-dual-energy-computed-tomography-for-artifact-reduction-in-the-head-neck-and-spine
#20
REVIEW
Eric Liao, Ashok Srinivasan
Conventional computed tomography (CT) uses a polychromatic energy beam to offer superb anatomic detail of the head and spine. However, technical challenges remain that can degrade the diagnostic image quality of these examinations. Dual-energy CT analyzes the changes in attenuation of soft tissues at different energy levels, from which different reconstructions can be made to yield the optimal contrast-to-noise ratio, reduce beam-hardening artifact, or evaluate tissue composition. In this article, selective applications of the dual energy CT technique are discussed, highlighting a powerful tool in the diagnostic CT evaluation of the head, neck, and spine...
August 2017: Neuroimaging Clinics of North America
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