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https://www.readbyqxmd.com/read/28725373/high-resolution-photo-mosaic-time-series-imagery-for-monitoring-human-use-of-an-artificial-reef
#1
Georgina Wood, Tim P Lynch, Carlie Devine, Krystle Keller, Will Figueira
Successful marine management relies on understanding patterns of human use. However, obtaining data can be difficult and expensive given the widespread and variable nature of activities conducted. Remote camera systems are increasingly used to overcome cost limitations of conventional labour-intensive methods. Still, most systems face trade-offs between the spatial extent and resolution over which data are obtained, limiting their application. We trialed a novel methodology, CSIRO Ruggedized Autonomous Gigapixel System (CRAGS), for time series of high-resolution photo-mosaic (HRPM) imagery to estimate fine-scale metrics of human activity at an artificial reef located 1...
October 2016: Ecology and Evolution
https://www.readbyqxmd.com/read/28717577/temporal-multiplexing-to-simulate-multifocal-intraocular-lenses-theoretical-considerations
#2
Vyas Akondi, Carlos Dorronsoro, Enrique Gambra, Susana Marcos
Fast tunable lenses allow an effective design of a portable simultaneous vision simulator (SimVis) of multifocal corrections. A novel method of evaluating the temporal profile of a tunable lens in simulating different multifocal intraocular lenses (M-IOLs) is presented. The proposed method involves the characteristic fitting of the through-focus (TF) optical quality of the multifocal component of a given M-IOL to a linear combination of TF optical quality of monofocal lenses viable with a tunable lens. Three different types of M-IOL designs are tested, namely: segmented refractive, diffractive and refractive extended depth of focus...
July 1, 2017: Biomedical Optics Express
https://www.readbyqxmd.com/read/28714067/evaluation-of-plastic-scintillator-detector-for-small-field-stereotactic-patient-specific-quality-assurance
#3
Yujiao Qin, Stephen J Gardner, Joshua Kim, Yimei Huang, Ning Wen, Anthony Doemer, Indrin J Chetty
PURPOSE: To evaluate the performance of a commercial plastic scintillator detector (PSD) for small-field stereotactic patient-specific quality assurance (QA) measurements using flattening-filter-free beam. METHODS: A total of ten spherical targets (volume range: [0.03cc-2cc]) were planned with two techniques: (1) Dynamic Conformal Arc (DCA-10 plans), and (2) Volumetric Modulated Arc Therapy (VMAT-10 plans). All plans were generated using Varian Eclipse treatment planning system, and AcurosXB v...
July 17, 2017: Medical Physics
https://www.readbyqxmd.com/read/28708557/blind-deep-s3d-image-quality-evaluation-via-local-to-global-feature-aggregation
#4
Heeseok Oh, Sewoong Ahn, Jongyoo Kim, Sanghoon Lee
Previously, no-reference (NR) stereoscopic 3D (S3D) image quality assessment (IQA) algorithms have been limited to the extraction of reliable hand-crafted features based on an understanding of the insufficiently revealed human visual system or natural scene statistics. Furthermore, compared with full-reference (FR) S3D IQA metrics, it is difficult to achieve competitive quality score predictions using the extracted features, which are not optimized with respect to human opinion. To cope with this limitation of the conventional approach, we introduce a novel deep learning scheme for NR S3D IQA in terms of local to global feature aggregation...
July 11, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28708549/effects-of-image-quality-on-the-fundamental-limits-of-image-registration-accuracy
#5
Michael D Ketcha, Tharindu De Silva, Runze Han, Ali Uneri, Joseph Goerres, Matthew Jacobson, Sebastian Vogt, Gerhard Kleinszig, Jeffrey H Siewerdsen
For image-guided procedures, the imaging task is often tied to the registration of intraoperative and preoperative images to a common coordinate system. While the accuracy of this registration is a vital factor in system performance, there is relatively little work that relates registration accuracy to image quality factors such as dose, noise, and spatial resolution. To create a theoretical model for such a relationship, we present a Fisher information approach to analyze registration performance in explicit dependence on the underlying image quality factors of image noise, spatial resolution, and signal power spectrum...
July 11, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28703331/high-resolution-diffusion-tensor-imaging-in-cervical-spondylotic-myelopathy-a-preliminary-follow-up-study
#6
Li Guan, Xiaolong Chen, Yong Hai, Xiaodong Ma, Le He, Guangzhi Wang, Chun Yuan, Hua Guo
Diffusion imaging is a promising technique as it can provide microstructural tissue information and thus potentially show viable changes in spinal cord. However, the traditional single-shot imaging method is limited as a result of various image artifacts. In order to improve measurement accuracy, we used a newly developed, multi-shot, high-resolution, diffusion tensor imaging (DTI) method to investigate diffusion metric changes and compare them with T2 -weighted (T2W) images before and after decompressive surgery for cervical spondylotic myelopathy (CSM)...
July 13, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28701915/web-camera-based-eye-tracking-to-assess-visual-memory-on-a-visual-paired-comparison-task
#7
Nicholas T Bott, Alex Lange, Dorene Rentz, Elizabeth Buffalo, Paul Clopton, Stuart Zola
Background: Web cameras are increasingly part of the standard hardware of most smart devices. Eye movements can often provide a noninvasive "window on the brain," and the recording of eye movements using web cameras is a burgeoning area of research. Objective: This study investigated a novel methodology for administering a visual paired comparison (VPC) decisional task using a web camera.To further assess this method, we examined the correlation between a standard eye-tracking camera automated scoring procedure [obtaining images at 60 frames per second (FPS)] and a manually scored procedure using a built-in laptop web camera (obtaining images at 3 FPS)...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28671565/efficient-depth-enhancement-using-a-combination-of-color-and-depth-information
#8
Kyungjae Lee, Yuseok Ban, Sangyoun Lee
Studies on depth images containing three-dimensional information have been performed for many practical applications. However, the depth images acquired from depth sensors have inherent problems, such as missing values and noisy boundaries. These problems significantly affect the performance of applications that use a depth image as their input. This paper describes a depth enhancement algorithm based on a combination of color and depth information. To fill depth holes and recover object shapes, asynchronous cellular automata with neighborhood distance maps are used...
July 1, 2017: Sensors
https://www.readbyqxmd.com/read/28665549/quality-measurement-for-rhinosinusitis-a-review-from-the-quality-improvement-committee-of-the-american-rhinologic-society
#9
Luke Rudmik, Jose Mattos, John Schneider, Peter R Manes, Janalee K Stokken, Jivianne Lee, Thomas S Higgins, Rodney J Schlosser, Douglas D Reh, Michael Setzen, Zachary M Soler
BACKGROUND: Measuring quality outcomes is an important prerequisite to improve quality of care. Rhinosinusitis represents a high value target to improve quality of care because it has a high prevalence of disease, large economic burden, and large practice variation. In this study we review the current state of quality measurement for management of both acute (ARS) and chronic rhinosinusitis (CRS). METHODS: The major national quality metric repositories and clearinghouses were queried...
June 30, 2017: International Forum of Allergy & Rhinology
https://www.readbyqxmd.com/read/28651069/automatic-mpst-cut-for-segmentation-of-carpal-bones-from-mr-volumes
#10
Laura Gemme, Sonia Nardotto, Silvana G Dellepiane
In the context of rheumatic diseases, several studies suggest that Magnetic Resonance Imaging (MRI) allows the detection of the three main signs of Rheumatoid Arthritis (RA) at higher sensitivities than available through conventional radiology. The rapid, accurate segmentation of bones is an essential preliminary step for quantitative diagnosis, erosion evaluation, and multi-temporal data fusion. In the present paper, a new, semi-automatic, 3D graph-based segmentation method to extract carpal bone data is proposed...
June 12, 2017: Computers in Biology and Medicine
https://www.readbyqxmd.com/read/28644794/electrocardiogram-signal-quality-assessment-based-on-structural-image-similarity-metric
#11
Yalda Shahriari, Richard Fidler, Michele Pelter, Yong Bai, Andrea Villaroman, Xiao Hu
OBJECTIVE: We developed an image-based electrocardiographic (ECG) quality assessment technique that mimics how clinicians annotate ECG signal quality. METHODS: We adopted the Structural Similarity Measure (SSIM) to compare images of two ECG records that are obtained from displaying ECGs in a standard scale. Then a subset of representative ECG images from the training set was selected as templates through a clustering method. SSIM between each image and all the templates were used as the feature vector for the linear discriminant analysis (LDA) classifier...
June 21, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28640906/quadratic-trigonometric-b-spline-for-image-interpolation-using-ga
#12
Malik Zawwar Hussain, Samreen Abbas, Misbah Irshad
In this article, a new quadratic trigonometric B-spline with control parameters is constructed to address the problems related to two dimensional digital image interpolation. The newly constructed spline is then used to design an image interpolation scheme together with one of the soft computing techniques named as Genetic Algorithm (GA). The idea of GA has been formed to optimize the control parameters in the description of newly constructed spline. The Feature SIMilarity (FSIM), Structure SIMilarity (SSIM) and Multi-Scale Structure SIMilarity (MS-SSIM) indices along with traditional Peak Signal-to-Noise Ratio (PSNR) are employed as image quality metrics to analyze and compare the outcomes of approach offered in this work, with three of the present digital image interpolation schemes...
2017: PloS One
https://www.readbyqxmd.com/read/28638218/new-endoscopes-and-add-on-devices-to-improve-colonoscopy-performance
#13
REVIEW
Paraskevas Gkolfakis, Georgios Tziatzios, George D Dimitriadis, Konstantinos Triantafyllou
Colonoscopy is the gold standard for colorectal cancer prevention; however, it is still an imperfect modality. Precancerous lesions can be lost during screening examinations, thus increasing the risk of interval cancer. A variety of factors either patient-, or endoscopist dependent or even the procedure itself may contribute to loss of lesions. Sophisticated modalities including advanced technology endoscopes and add-on devices have been developed in an effort to eliminate colonoscopy's drawbacks and maximize its ability to detect potentially culprit polyps...
June 7, 2017: World Journal of Gastroenterology: WJG
https://www.readbyqxmd.com/read/28629955/correlation-study-between-dki-and-conventional-dwi-in-brain-and-head-and-neck-tumors
#14
Silvia Minosse, Simona Marzi, Francesca Piludu, Antonello Vidiri
PURPOSE: To investigate the relationship between the Diffusion Kurtosis Imaging (DKI) parameters and conventional metrics provided by Diffusion-weighted imaging (DWI) in patients affected by Brain or Head and Neck (HN) cancer. METHODS: Ten patients affected by brain tumor and nine patients with HN tumor underwent a pre-treatment MR examination at 3 T. The largest tumor section was manually contoured by two expert neuroradiologists. The apparent diffusion coefficient (Dapp) and apparent diffusional kurtosis (Kapp) parameters were determined at the voxel level by using the DKI model, and compared to the apparent diffusion coefficient (ADC) and the tissue diffusion coefficient (Dmono) obtained from mono-exponential fitting methods...
June 16, 2017: Magnetic Resonance Imaging
https://www.readbyqxmd.com/read/28626962/three-dimensional-motion-corrected-sensitivity-encoding-reconstruction-for-multi-shot-multi-slice-mri-application-to-neonatal-brain-imaging
#15
Lucilio Cordero-Grande, Emer J Hughes, Jana Hutter, Anthony N Price, Joseph V Hajnal
PURPOSE: To introduce a methodology for the reconstruction of multi-shot, multi-slice magnetic resonance imaging able to cope with both within-plane and through-plane rigid motion and to describe its application in structural brain imaging. THEORY AND METHODS: The method alternates between motion estimation and reconstruction using a common objective function for both. Estimates of three-dimensional motion states for each shot and slice are gradually refined by improving on the fit of current reconstructions to the partial k-space information from multiple coils...
June 19, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28606763/application-of-eye-tracking-in-medicine-a-survey-research-issues-and-challenges
#16
Katarzyna Harezlak, Pawel Kasprowski
The performance and quality of medical procedures and treatments are inextricably linked to technological development. The application of more advanced techniques provides the opportunity to gain wider knowledge and deeper understanding of the human body and mind functioning. The eye tracking methods used to register eye movement to find the direction and targets of a person's gaze are well in line with the nature of the topic. By providing methods for capturing and processing images of the eye it has become possible not only to reveal abnormalities in eye functioning but also to conduct cognitive studies focused on learning about peoples' emotions and intentions...
May 30, 2017: Computerized Medical Imaging and Graphics: the Official Journal of the Computerized Medical Imaging Society
https://www.readbyqxmd.com/read/28606456/extended-depth-of-focus-contact-lenses-vs-two-commercial-multifocals-part-1-optical-performance-evaluation-via-computed-through-focus-retinal-image-quality-metrics
#17
Ravi C Bakaraju, Klaus Ehrmann, Arthur Ho
PURPOSE: To compare the computed optical performance of prototype lenses designed using deliberate manipulation of higher-order spherical aberrations to extend depth-of-focus (EDOF) with two commercial multifocals. METHODS: Emmetropic, presbyopic, schematic eyes were coupled with prototype EDOF and commercial multifocal lenses (Acuvue Oasys for presbyopia, AOP, Johnson & Johnson & Air Optix Aqua multifocal, AOMF, Alcon). For each test configuration, the through-focus retinal image quality (TFRIQ) values were computed over 21 vergences, ranging from -0...
June 9, 2017: Journal of Optometry
https://www.readbyqxmd.com/read/28595774/feasibility-of-using-single-photon-counting-x-ray-for-lung-tumor-position-estimation-based-on-4d-ct
#18
Katharina P Aschenbrenner, Christian V Guthier, Yulia Lyatskaya, Judit Boda-Heggemann, Frederik Wenz, Jürgen W Hesser
PURPOSE: In stereotactic body radiation therapy of lung tumors, reliable position estimation of the tumor is necessary in order to minimize normal tissue complication rate. While kV X-ray imaging is frequently used, continuous application during radiotherapy sessions is often not possible due to concerns about the additional dose. Thus, ultra low-dose (ULD) kV X-ray imaging based on a single photon counting detector is suggested. This paper addresses the lower limit of photons to locate the tumor reliably with an accuracy in the range of state-of-the-art methods, i...
June 5, 2017: Zeitschrift Für Medizinische Physik
https://www.readbyqxmd.com/read/28587192/high-dynamic-range-spectral-imaging-pipeline-for-multispectral-filter-array-cameras
#19
Pierre-Jean Lapray, Jean-Baptiste Thomas, Pierre Gouton
Spectral filter arrays imaging exhibits a strong similarity with color filter arrays. This permits us to embed this technology in practical vision systems with little adaptation of the existing solutions. In this communication, we define an imaging pipeline that permits high dynamic range (HDR)-spectral imaging, which is extended from color filter arrays. We propose an implementation of this pipeline on a prototype sensor and evaluate the quality of our implementation results on real data with objective metrics and visual examples...
June 3, 2017: Sensors
https://www.readbyqxmd.com/read/28585300/investigation-of-error-detection-capabilities-of-phantom-epid-and-mlc-log-file-based-imrt-qa-methods
#20
Dewayne L Defoor, Sotirios Stathakis, Joseph E Roring, Neil A Kirby, Panayiotis Mavroidis, Mohammad Obeidat, Nikos Papanikolaou
A patient specific quality assurance (QA) should detect errors that originate anywhere in the treatment planning process. However, the increasing complexity of treatment plans has increased the need for improvements in the accuracy of the patient specific pretreatment verification process. This has led to the utilization of higher resolution QA methods such as the electronic portal imaging device (EPID) as well as MLC log files and it is important to know the types of errors that can be detected with these methods...
June 6, 2017: Journal of Applied Clinical Medical Physics
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