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Yasuharu Wakabayashi, Kenichi Kashikura, Yasuyuki Takahashi, Hitoshi Yabe, Akihiro Ichikawa, Souichi Yamamoto, Ayumi Ishii, Kunio Doi
OBJECTIVES: The present study was conducted to examine whether the standardized uptake value (SUV) may be affected by the spatial position of a lesion in the radial direction on positron emission tomography (PET) images, obtained via two methods based on time-of-flight (TOF) reconstruction and point spread function (PSF). METHODS: A cylinder phantom with the sphere (30 mm diameter), located in the center was used in this study. Fluorine-18 fluorodeoxyglucose ((18)F-FDG) concentrations of 5...
2016: Asia Oceania Journal of Nuclear Medicine & Biology
Junlei Zhao, Fei Xiao, Jian Kang, Haoxin Zhao, Yun Dai, Yudong Zhang
Measurement of the double-pass (DP) point-spread function (PSF) can provide an objective and non-invasive method for estimating intraocular scatter in the human eye. The objective scatter index (OSI), which is calculated from the DP PSF images, is commonly used to quantify intraocular scatter. In this article, we simulated the effect of higher-order ocular aberrations on OSI, and the results showed that higher-order ocular aberrations had a significant influence on OSI. Then we developed an adaptive optics DP PSF measurement system (AO-DPPMS) which was capable of correcting ocular aberrations up to eighth-order radial Zernike modes over a 6...
November 1, 2016: Biomedical Optics Express
Kenichiro Tanaka, Yasuhiro Mukaigawa, Hiruyuki Kubo, Yasuyuki Matsushita, Yasushi Yagi
This paper describes a method for recovering appearance of inner slices of translucent objects. The appearance of a layered translucent object is the summed appearance of all layers, where each layer is blurred by a depth-dependent point spread function (PSF). By exploiting the difference of low-pass characteristics of depth-dependent PSFs, we develop a multi-frequency illumination method for obtaining the appearance of individual inner slices. Specifically, by observing the target object with varying the spatial frequency of checker-pattern illumination, our method recovers the appearance of inner slices via computation...
November 23, 2016: IEEE Transactions on Pattern Analysis and Machine Intelligence
Nicolas A Karakatsanis, Charalampos Tsoumpas, Habib Zaidi
Bulk body motion may randomly occur during PET acquisitions introducing blurring, attenuation-emission mismatches and, in dynamic PET, discontinuities in the measured time activity curves between consecutive frames. Meanwhile, dynamic PET scans are longer, thus increasing the probability of bulk motion. In this study, we propose a streamlined 3D PET motion-compensated image reconstruction (3D-MCIR) framework, capable of robustly deconvolving intra-frame motion from a static or dynamic 3D sinogram. The presented 3D-MCIR methods need not partition the data into multiple gates, such as 4D MCIR algorithms, or access list-mode (LM) data, such as LM MCIR methods, both associated with increased computation or memory resources...
November 16, 2016: Computerized Medical Imaging and Graphics: the Official Journal of the Computerized Medical Imaging Society
Fei Fang, Xue-Yan Zhu, ChenChen, Jing Li, Da-Jing Chen, Xiao-Jun Huang
: An anionic glycosylated polysulfone (PSf) membrane was prepared as a high-affinity adsorbent for low-density lipoprotein (LDL). The UV-induced grafting of acrylic acid to the membrane was followed by amidation and a 'thiol-yne' click reaction to achieve glycosylation and sulfonation. Membrane modification was confirmed by attenuated total reflectance-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. These tests revealed that the chemical compositions of the membranes' surfaces were easily regulated by controlling the 'thiol-yne' click reaction through the feed ratio of 2,3,4,6-tetra-O-acetyl-1-thio-β-D-glucopyranose and sodium 3-mercapto-1-propanesulfonate...
November 21, 2016: Acta Biomaterialia
Dimitrios Christaras, Harilaos Ginis, Alexandros Pennos, Pablo Artal
Intraocular scattering affects fundus imaging in a similar way that affects vision; it causes a decrease in contrast which depends on both the intrinsic scattering of the eye but also on the dynamic range of the image. Consequently, in cases where the absolute intensity in the fundus image is important, scattering can lead to a wrong estimation. In this paper, a setup capable of acquiring fundus images and estimating objectively intraocular scattering was built, and the acquired images were then used for scattering compensation in fundus imaging...
October 1, 2016: Biomedical Optics Express
Smi Choi-Kwon, Mihye Ko, Sang-Eun Jun, Juhan Kim, Kyung-Hee Cho, Hyun-Wook Nah, Hasup Song, Jong S Kim
BACKGROUND: Post-stroke fatigue (PSF) is a common sequela of stroke. Despite reports of serotonergic involvement in the etiology of PSF, the potential contribution of serotonergic genes in the development of PSF needs to be investigated. METHODS: A total of 373 patients, who experienced ischemic stroke for PSF, were evaluated 3 months after the stroke. PSF was assessed using the Fatigue Severity Scale. The genomic DNA collected and stored in a -70°C freezer was genotyped for 6 polymorphisms in genes associated with serotonin synthesis (tryptophan hydroxylase 1 (TPH1) A218C, TPH2 rs10879355, and TPH2 rs4641528), transport (the promoter region of the serotonin transporter protein), and catabolism (the 30-bp functional variable number tandem repeat) polymorphism in the promoter region of monoamine oxidase A (MAO-A)...
November 19, 2016: Cerebrovascular Diseases
Andrew Kulmatiski, Karen H Beard, Josephine Grenzer, Leslie Forero, Justin Heavilin
It has become clear that plants can create soils that affect subsequent plant growth. However, because plant-soil feedbacks (PSFs) are typically measured in monoculture experiments, it remains unclear to what extent PSFs affect plant growth in communities. Here we used data from a factorial PSF experiment to predict the biomass of 12 species grown in 162 plant community combinations. Five different plant growth models were parameterized with either monoculture biomass data (Null) or with PSF data (PSF) and model predictions were compared to plant growth observed in communities...
August 2016: Ecology
R Kirk Owens, Mladen Djurasovic, Charles H Crawford, Steven D Glassman, John R Dimar, Leah Y Carreon
Study Design Retrospective comparative cohort. Objective Pseudarthrosis following fusion for degenerative lumbar spine pathologies remains a substantial problem. Current data shows that patients who develop a pseudarthrosis have suboptimal outcomes. This study evaluates if treatment of pseudarthrosis can be affected by surgical approach. Methods Medical records of 63 female and 65 male patients (mean age 50.37) who were treated for nonunion following lumbar fusion were reviewed. Sixty patients underwent posterolateral fusion (PSF), 18 underwent PSF with transforaminal interbody fusion (TLIF), 32 underwent anterior and posterior spinal fusion (AP), and 24 underwent anterior lumbar interbody fusion (ALIF)...
December 2016: Global Spine Journal
Yang Gao, Yanfeng Bai, Xiquan Fu
The point-spread function (PSF) is fundamental importance in estimating the imaging resolution in optical imaging systems. By using the Collins formula, a analytical imaging formula for ghost imaging system is obtained. The intensity fluctuation correlation function can be viewed as the convolution of the original object and a PSF. The imaging resolution is determined by the width of PSF. Based on the optical transfer matrix theory, we present the analytical formula describing the width of the PSF, by which one can estimate imaging resolution of a new-designed imaging scheme when compared with that of the existing imaging system...
October 31, 2016: Optics Express
Brandon G Zimmerman, Thomas G Brown
We present an analysis and test of an image sampling polarimeter based on the concept of Star Test Polarimetry first introduced by Ramkhalawon. The method makes use of a stress engineered optical element (SEO) placed in the pupil plane of an optical system to induce a polarization dependent point spread function (PSF) at the detector. We describe the calibration requirements of the polarimeter and introduce a new algorithm that can robustly extract the Stokes parameters in a single irradiance measurement. By acquiring statistics on the sampled Stokes parameters of a uniformly illuminated pinhole array, we show that a single frame can provide a root mean square angular error of approximately 10 milliradians on the Poincaré sphere...
October 3, 2016: Optics Express
Dong Zhang, Xiaobin Zhang, Shuyan Xu, Nannan Liu, Luoxin Zhao
We present a simplified solution to phase diversity when the observed object is a point source. It utilizes an iterative linearization of the point spread function (PSF) at two or more diverse planes by first-order Taylor expansion to reconstruct the initial wavefront. To enhance the influence of the PSF in the defocal plane which is usually very dim compared to that in the focal plane, we build a new model with the Tikhonov regularization function. The new model cannot only increase the computational speed, but also reduce the influence of the noise...
October 1, 2016: Applied Optics
Anthony P Leonard, Scott D Gardner, Karolinne M Rocha, Evan R Zeldin, David M Tremblay, George O Waring
PURPOSE: To measure retinal image quality using point spread function (PSF) analysis by double-pass retina point imaging in patients with keratoconus and to correlate visual quality with disease severity. METHODS: Patients diagnosed as having keratoconus by clinical examination, topography, and tomography and normal eyes were included in this study. A commercially available double-pass retina point imaging instrument (OQAS 108 II AcuTarget HD; Visiometrics S.L., Terrassa, Spain) was used to collect Objective Scatter Index (OSI) values in 21 keratoconic and 22 normal eyes...
November 1, 2016: Journal of Refractive Surgery
Nasser S Ahmadi, Louise Bennet, Charlotte A Larsson, Susanne Andersson, Jörgen Månsson, Ulf Lindblad
AIMS: Left ventricular hypertrophy, obesity, hypertension, and N-terminal B-type natriuretic peptide (Nt-proBNP) predict left ventricular diastolic dysfunction with preserved systolic function (DD-PSF). Self-rated health (SRH) is shown to be associated with chronic diseases, but the association of SRH with DD-PSF is unclear. In light of the clinical implications of DD-PSF, the following goals are of considerable importance: (1) to determine the role of SRH in patients with DD-PSF in the general population and (2) to study the association between Nt-proBNP and DD-PSF...
September 2016: ESC Heart Failure
Feihu Li, Bingtao Tang, Suli Wu, Shufen Zhang
The synthesis and assembly of monodispersed colloidal spheres are currently the subject of extensive investigation to fabricate artificial structural color materials. However, artificial structural colors from general colloidal crystals still suffer from the low color visibility and strong viewing angle dependence which seriously hinder their practical application in paints, colorimetric sensors, and color displays. Herein, monodispersed polysulfide (PSF) spheres with intrinsic high refractive index (as high as 1...
November 3, 2016: Small
Charline Lasnon, Thibault Salomon, Cédric Desmonts, Pascal Dô, Youssef Oulkhouir, Jeannick Madelaine, Nicolas Aide
BACKGROUND: Evolutions in hardware and software PET technology, such as point spread function (PSF) reconstruction, have been shown to improve diagnostic performance, but can also lead to important device-dependent and reconstruction-dependent variations in standardized uptake values (SUVs). This may preclude the multicentre use of SUVs as a prognostic or diagnostic tool or as a biomarker of the early response to antineoplastic treatments. This study compared two SUV harmonization strategies using a newer reconstruction algorithm that improves lesion detection while maintaining comparability with older systems: (1) the use of a second reconstruction compliant with harmonization standards and (2) the use of a proprietary software tool (EQ...
November 3, 2016: Annals of Nuclear Medicine
Samuel Matej, Yusheng Li, Joseph Panetta, Joel S Karp, Suleman Surti
The point-spread-functions (PSFs) of reconstructed images can be deformed due to detector effects such as resolution blurring and parallax error, data acquisition geometry such as insufficient sampling or limited angular coverage in dual-panel PET systems, or reconstruction imperfections/simplifications. PSF deformation decreases quantitative accuracy and its spatial variation lowers consistency of lesion uptake measurement across the imaging field-of-view (FOV). This can be a significant problem with dual panel PET systems even when using TOF data and image reconstruction models of the detector and data acquisition process...
October 2016: IEEE Transactions on Nuclear Science
Mohd Afzal, Saptarshi Ghosh, Sinjan Das, Nitin Chattopadhyay
The photophysics of phenosafranin (PSF), a member of the photosensitizer phenazinium family, has been explored in nonionic Triton X-165 (TX-165) micelle, calf thymus DNA (ctDNA), and a composite environment consisting of both micelle and DNA, using diverse spectroscopic techniques of both steady-state and time-resolved natures, to divulge the binding interactions of the probe with different hosts. The vivid experimental results demonstrate that PSF binds with both micelle and DNA; however, the binding affinity of the probe is much higher toward the DNA...
November 1, 2016: Journal of Physical Chemistry. B
Wenxiao Wang, Hao Shen, Bo Shuang, Benjamin S Hoener, Lawrence J Tauzin, Nicholas A Moringo, Kevin F Kelly, Christy F Landes
Super-resolution microscopy typically achieves high spatial resolution, but the temporal resolution remains low. We report super temporal-resolved microscopy (STReM) to improve the temporal resolution of 2D super-resolution microscopy by a factor of 20 compared to that of the traditional camera-limited frame rate. This is achieved by rotating a phase mask in the Fourier plane during data acquisition and then recovering the temporal information by fitting the point spread function (PSF) orientations. The feasibility of this technique is verified with both simulated and experimental 2D adsorption/desorption and 2D emitter transport...
October 31, 2016: Journal of Physical Chemistry Letters
Mohd Afzal, Saptarshi Ghosh, Nitin Chattopadhyay
Relocation of a bioactive photosensitizer, namely phenosafranin (PSF), from the phenazinium family, has been demonstrated from non-ionic micellar carrier to the DNA. For the purpose, interaction of micelle-bound PSF with calf thymus DNA (ctDNA) has been investigated vividly exploiting various spectroscopic techniques like absorption, steady state and time resolved emission, fluorescence anisotropy, circular dichroism etc. Experimental outcomes reveal that PSF binds strongly with both the micelle as well as the DNA...
October 23, 2016: Biophysical Chemistry
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