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https://www.readbyqxmd.com/read/27867178/mtf-measurement-of-mr-blurring-in-liver-dynamic-mri-with-gd-eob-dtpa
#1
Masashi Kikuchi, Norio Hayashi, Kazuma Yarita, Kozue Sakata, Koichi Ujita, Satoshi Matsuda, Yuichi Teduka
During the arterial phase acquisition of Gd-EOB-DTPA examinations, use of a small volume of the Gd-EOB-DTPA may make it difficult the encoding center of the k-space, and produce blurring. The previous studies revealed the encoding technique of the k-space was one of the most important reasons. However, there is no report to discuss the reasons with quantitative evaluations. The purpose of this study was to quantitatively evaluate the characteristics of the artifacts using different k-space encoding techniques (centric-view ordering (CVO) and sequential-view ordering (SVO)) for liver dynamic MRI in computer simulation study...
2016: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/27849456/the-bridging-advanced-developments-for-exceptional-rehabilitation-bader-consortium-reaching-in-partnership-for-optimal-orthopaedic-rehabilitation-outcomes
#2
Steven J Stanhope, Jason M Wilken, Alison L Pruziner, Christopher L Dearth, Marilynn Wyatt, Gregg W Ziemke, Rachel Strickland, Suzanne A Milbourne, Kenton R Kaufman
The Bridging Advanced Developments for Exceptional Rehabilitation (BADER) Consortium began in September 2011 as a cooperative agreement with the Department of Defense (DoD) Congressionally Directed Medical Research Programs Peer Reviewed Orthopaedic Research Program. A partnership was formed with DoD Military Treatment Facilities (MTFs), U.S. Department of Veterans Affairs (VA) Centers, the National Institutes of Health (NIH), academia, and industry to rapidly conduct innovative, high-impact, and sustainable clinically relevant research...
November 2016: Military Medicine
https://www.readbyqxmd.com/read/27830287/-social-support-in-gender-reassignment-surgery
#3
J Hess, I Kurth, A Henkel, L Panic, H Rübben, R Rossi Neto, Y Hess-Busch
BACKGROUND: Gender reassignment surgery (GRS) can lead to discrimination. This transition makes great demands on the individual and also affects the social environment. OBJECTIVES: To evaluate the social support of male-to-female (MtF) transgender people. MATERIALS AND METHODS: Group A comprised 254 consecutive MtF transsexuals, who received a penile inversion vaginoplasty between 2004 and 2010. These women were surveyed retrospectively...
November 9, 2016: Der Urologe. Ausg. A
https://www.readbyqxmd.com/read/27828150/mtf-performance-verification-of-an-athermalized-large-aperture-ir-optical-system-for-space-environment
#4
Se-Chol Choi, Byoung-Soo Kim, Hyunjin Lim, Hongchul Sim, Hongyeon Hwang
We develop an athermalized IR optical system operating in the temperature range of 10°C-30°C in vacuum. As large defocus errors can occur in IR optical systems in such an environment, we estimate the amount of defocus induced by the thermoelastic effect, thermo-optic effect, and air-to-vacuum transition. Furthermore, we measure the modulation transfer function (MTF) performance of our IR optical system in a thermal vacuum chamber. Our athermal system design and accurate estimation of the air-to-vacuum transition effect enable the realization of a stable IR optical system for a space environment, which exhibits an MTF value greater than 18%...
October 20, 2016: Applied Optics
https://www.readbyqxmd.com/read/27824962/a-novel-method-for-the-optimization-of-positron-emission-tomography-scanners-imaging-performance
#5
Christos M Michail, George E Karpetas, George P Fountos, Nektarios I Kalyvas, Ioannis G Valais, Christina Fountzoula, Antonis Zanglis, Ioannis S Kandarakis, George S Panayiotakis
OBJECTIVE: The aim of the present study was to propose a comprehensive method for positron emission tomography (PET) scanners image quality assessment, by simulation of a thin layer chromatography (TLC) flood source with a previously validated Monte Carlo model. METHODS AND MATERIALS: We used the GATE Monte Carlo package (GEANT4 application for tomographic emission) and the reconstructed images were obtained using the software for tomographic image reconstruction (STIR), with cluster computing...
November 8, 2016: Hellenic Journal of Nuclear Medicine
https://www.readbyqxmd.com/read/27822664/assessment-of-motivational-cognitions-in-diabetes-self-care-the-motivation-thought-frequency-scales-for-glucose-testing-physical-activity-and-healthy-eating
#6
Sophie C Parham, David J Kavanagh, Christian A Gericke, Neil King, Jon May, Jackie Andrade
PURPOSE: There is a need for improved measurement of motivation for diabetes self-care. The Elaborated Intrusion Theory of Desire offers a coherent framework for understanding and identifying the cognitive-affective events that constitute the subjective experience of motivation and may therefore inform the development of such an instrument. Recent research has shown the resultant Motivation Thought Frequency scale (MTF) to have a stable factor structure (Intensity, Incentives Imagery, Self-Efficacy Imagery, Availability) when applied to physical activity, excessive snacking or alcohol use in the general population...
November 7, 2016: International Journal of Behavioral Medicine
https://www.readbyqxmd.com/read/27782719/correlation-between-k-space-sampling-pattern-and-mtf-in-compressed-sensing-mrsi
#7
A A Heikal, K Wachowicz, B G Fallone
PURPOSE: To investigate the relationship between the k-space sampling patterns used for compressed sensing MR spectroscopic imaging (CS-MRSI) and the modulation transfer function (MTF) of the metabolite maps. This relationship may allow the desired frequency content of the metabolite maps to be quantitatively tailored when designing an undersampling pattern. METHODS: Simulations of a phantom were used to calculate the MTF of Nyquist sampled (NS) 32 × 32 MRSI, and four-times undersampled CS-MRSI reconstructions...
October 2016: Medical Physics
https://www.readbyqxmd.com/read/27782715/isotope-independent-determination-of-pet-ct-modulation-transfer-functions-from-phantom-measurements-on-spheres
#8
George A Prenosil, Bernd Klaeser, Michael Hentschel, Markus Fürstner, Michael Berndt, Thomas Krause, Thilo Weitzel
PURPOSE: A PET/CT system's imaging capabilities are best described by its point spread function (PSF) in the spatial domain or equivalently by its modulation transfer function (MTF) in the spatial frequency domain. Knowing PSFs or MTFs is a prerequisite for many numerical methods attempting to improve resolution and to reduce the partial volume effect. In PET/CT, the observed PSF is a convolution of the system's intrinsic imaging capabilities including image reconstruction (PSF0) and the positron range function (PRF) of the imaged β(+) emitting isotope...
October 2016: Medical Physics
https://www.readbyqxmd.com/read/27782684/technical-note-an-oversampling-procedure-to-calculate-the-mtf-of-an-imaging-system-from-a-bar-pattern-image
#9
Antonio González-López, Pedro Antonio Campos-Morcillo, José Domingo Lago-Martín
PURPOSE: Line-pair resolution phantoms are used to determine the spatial resolution of medical imaging systems. In some cases, these phantoms are used to determine the maximum number of line-pairs per mm that the system can resolve. In other cases, a numerical determination of the modulation transfer function (MTF) is carried out by means of the analysis of the variance of ROIs on the image. In this note, a new procedure is implemented to calculate the presampled MTF of an imaging system...
October 2016: Medical Physics
https://www.readbyqxmd.com/read/27782056/analysis-of-crack-image-recognition-characteristics-in-concrete-structures-depending-on-the-illumination-and-image-acquisition-distance-through-outdoor-experiments
#10
Hyun-Woo Cho, Hyuk-Jin Yoon, Jae-Chan Yoon
The effects of illumination and shooting distance on crack image recognition were investigated by examining cracks in images taken with a camera. In order to examine the effects, images of cracks in a concrete structure taken while varying the illumination and shooting distance in an outdoor environment were analyzed. The images were acquired at a daytime illumination of 52,000 lx and a night illumination of 13 lx. The crack specimen images produced for the experiment were taken by increasing the shooting distance from 5 m to 100 m in each illumination...
October 6, 2016: Sensors
https://www.readbyqxmd.com/read/27776082/effect-of-decentration-on-the-optical-quality-of-two-intraocular-lenses
#11
Carolina Ortiz, José J Esteve-Taboada, Lurdes Belda-Salmerón, Daniel Monsálvez-Romín, Alberto Domínguez-Vicent
PURPOSE: To analyze the effect of decentration on the optical quality of two diffractive-refractive intraocular lenses, a bifocal and a trifocal, when displaced laterally (horizontal direction) from the center. METHODS: The AT LISA 809M IOL (+3.75 D add) with two main foci and the AT LISA tri 839MP intraocular lens with three main foci (Carl Zeiss Meditec AG, Jena, Germany) were analyzed. The optical quality of the intraocular lenses was measured with the PMTF (power and modulation transfer function [MTF] measurement for refractive and diffractive intraocular lenses) optical bench (Lambda-X, Nivelles, Belgium)...
December 2016: Optometry and Vision Science: Official Publication of the American Academy of Optometry
https://www.readbyqxmd.com/read/27754987/npwe-model-observer-as-a-validated-alternative-for-contrast-detail-analysis-of-digital-detectors-in-general-radiography
#12
N Van Peteghem, H Bosmans, N W Marshall
To propose and validate a non-prewhitening with eye filter (NPWE) model observer as an alternative means of quantifying and specifying imaging performance for general radiography detectors, in a comparative study with contrast detail analysis and detective quantum efficiency (DQE). Five different x-ray detectors were assessed, covering a range of detector technologies including powder computed radiography (CR), needle CR, and three indirect conversion flat panel digital radiography detectors (DR). For each detector, threshold contrast detail (c-d) detectability was measured using the Leeds TO20 test object...
November 7, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27752404/cone-beam-ct-vs-fan-beam-ct-a-comparison-of-image-quality-and-dose-delivered-between-two-differing-ct-imaging-modalities
#13
Lawrence Lechuga, Georg A Weidlich
A comparison of image quality and dose delivered between two differing computed tomography (CT) imaging modalities-fan beam and cone beam-was performed. A literature review of quantitative analyses for various image quality aspects such as uniformity, signal-to-noise ratio, artifact presence, spatial resolution, modulation transfer function (MTF), and low contrast resolution was generated. With these aspects quantified, cone beam computed tomography (CBCT) shows a superior spatial resolution to that of fan beam, while fan beam shows a greater ability to produce clear and anatomically correct images with better soft tissue differentiation...
September 12, 2016: Curēus
https://www.readbyqxmd.com/read/27746099/in-silico-investigation-of-factors-affecting-the-mv-imaging-performance-of-a-novel-water-equivalent-epid
#14
Samuel J Blake, Zhangkai Cheng, Shaghik Atakaramians, Steven Meikle, Minghui Lu, Philip Vial, Zdenka Kuncic
PURPOSE: A Geant4 model of a novel, water-equivalent electronic portal imaging device (EPID) prototype for radiotherapy imaging and dosimetry utilising an array of plastic scintillating fibres (PSFs) has been developed. Monte Carlo (MC) simulations were performed to quantify the PSF-EPID imaging performance and to investigate design aspects affecting performance for optimisation. METHODS: Using the Geant4 model, the PSF-EPID's imaging performance for 6 MV photon beams was quantified in terms of its modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE)...
October 13, 2016: Physica Medica: PM
https://www.readbyqxmd.com/read/27744092/subcortical-gray-matter-changes-in-transgender-subjects-after-long-term-cross-sex-hormone-administration
#15
Rene Seiger, Andreas Hahn, Allan Hummer, Georg S Kranz, Sebastian Ganger, Michael Woletz, Christoph Kraus, Ronald Sladky, Alexander Kautzky, Siegfried Kasper, Christian Windischberger, Rupert Lanzenberger
Sex-steroid hormones are primarily involved in sexual differentiation and development and are thought to underlie processes related to cognition and emotion. However, divergent results have been reported concerning the effects of hormone administration on brain structure including side effects like brain atrophy and dementia. Cross-sex hormone therapy in transgender subjects offers a unique model for studying the effects of sex hormones on the living human brain. In this study, 25 Female-to-Male (FtM) and 14 Male-to-Female (MtF) subjects underwent MRI examinations at baseline and after a period of at least 4-months of continuous cross-sex hormone administration...
October 5, 2016: Psychoneuroendocrinology
https://www.readbyqxmd.com/read/27731346/head-mounted-dmd-based-projection-system-for-natural-and-prosthetic-visual-stimulation-in-freely-moving-rats
#16
Tamar Arens-Arad, Nairouz Farah, Shai Ben-Yaish, Alex Zlotnik, Zeev Zalevsky, Yossi Mandel
Novel technologies are constantly under development for vision restoration in blind patients. Many of these emerging technologies are based on the projection of high intensity light patterns at specific wavelengths, raising the need for the development of specialized projection systems. Here we present and characterize a novel projection system that meets the requirements for artificial retinal stimulation in rats and enables the recording of cortical responses. The system is based on a customized miniature Digital Mirror Device (DMD) for pattern projection, in both visible (525 nm) and NIR (915 nm) wavelengths, and a lens periscope for relaying the pattern directly onto the animal's retina...
October 12, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27727117/cone-beam-micro-computed-tomography-dedicated-to-the-breast
#17
Antonio Sarno, Giovanni Mettivier, Francesca Di Lillo, Mario Cesarelli, Paolo Bifulco, Paolo Russo
We developed a scanner for micro computed tomography dedicated to the breast (BµCT) with a high resolution flat-panel detector and a microfocus X-ray tube. We evaluated the system spatial resolution via the 3D modulation transfer function (MTF). In addition to conventional absorption-based X-ray imaging, such a prototype showed capabilities for propagation-based phase-contrast and related edge enhancement effects in 3D imaging. The system limiting spatial resolution is 6.2mm(-1) (MTF at 10%) in the vertical direction and 3...
October 7, 2016: Medical Engineering & Physics
https://www.readbyqxmd.com/read/27698953/training-enhances-immune-cells-mitochondrial-biosynthesis-fission-fusion-and-their-antioxidant-capabilities-synergistically-with-dietary-docosahexaenoic-supplementation
#18
Carla Busquets-Cortés, Xavier Capó, Miquel Martorell, Josep A Tur, Antoni Sureda, Antoni Pons
Exercise training induces adaptations in mitochondrial metabolism, dynamics, and oxidative protection. Omega-3 fatty acids change membrane lipid composition and modulate mitochondrial function. The aim was to investigate the effect of 8-week training and docosahexaenoic acid (DHA) supplementation (1.14 g/day) on the mitochondria dynamics and antioxidant status in peripheral blood mononuclear cells (PBMCs) from sportsmen. Subjects were assigned to an intervention (N = 9) or placebo groups (N = 7) in a randomized double-blind trial...
2016: Oxidative Medicine and Cellular Longevity
https://www.readbyqxmd.com/read/27697256/optical-bench-performance-of-3-trifocal-intraocular-lenses
#19
Daniel Carson, Zaiwei Xu, Elsinore Alexander, Myoung Choi, Zeyu Zhao, Xin Hong
PURPOSE: To compare the optical performance of 3 trifocal intraocular lenses (IOLs): the Acrysof IQ Panoptix (+2.17 diopter [D]/+3.25 D IOL), AT LISA Tri 839MP (+1.66 D/+3.33 D IOL), and Finevision Micro F (+1.75 D/+3.50 D IOL). SETTING: Alcon Research Ltd., Fort Worth, Texas, USA. DESIGN: Experimental study. METHODS: The 3 trifocal IOLs were compared using optical performance tests. To measure image quality, through-focus modulation transfer function (MTF) curves were generated for a model eye...
September 2016: Journal of Cataract and Refractive Surgery
https://www.readbyqxmd.com/read/27686883/patterns-of-sexual-behaviour-and-sexual-healthcare-needs-among-transgender-individuals-in-melbourne-australia-2011-2014
#20
Clare Bellhouse, Sandra Walker, Christopher K Fairley, Lenka A Vodstrcil, Catriona S Bradshaw, Marcus Y Chen, Eric P F Chow
OBJECTIVE: Literature surrounding the healthcare needs of transgender individuals is limited in Australia. This study aimed to investigate the demographic characteristics, risk behaviours and HIV/STI positivity among male-to-female (MTF) and female-to-male (FTM) transgender individuals attending Melbourne Sexual Health Centre (MSHC), Australia, between 2011 and 2014. METHOD: A retrospective cohort analysis for 133 transgender individuals was conducted based on the first visit of individuals to MSHC during the study period...
September 29, 2016: Sexually Transmitted Infections
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