Coded-aperture imagers typically have a smaller field-of-view (FOV) than in un-collimated gamma imaging systems. However, sources out of the fully coded field-of-view (FCFOV) can cause pseudo hotspots on the wrong side of an image reconstructed using the cross-correlation method. In this work, we propose a neural network method to identify and localize the sources within the partially coded field-of-view (PCFOV). The model was trained using Monte Carlo simulation data and evaluated with both simulation and experimental data. The results showed that the proposed model can identify and localize sources with good classification accuracy, low positioning error, and strong robustness to the statistical noise.
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http://dx.doi.org/10.1016/j.apradiso.2021.109637 | DOI Listing |
Ultrasonics
March 2025
Department of Electrical and Computer Engineering, University of Alberta, Edmonton, T6G 1H9, AB, Canada.
3D synthetic aperture (SA) imaging of volumes can be obtained using sparse 2D ultrasound arrays. However, even with just 256 elements, the volumetric imaging rate can be relatively slow due to having to transmit on each element in succession. Hadamard Aperiodic Interval (HAPI) codes can be used to image the full SA dataset in one extended transmit to speed up the synthetic aperture imaging, but their long nature produces large deadzones if the same elements are used as both transmitters and receivers.
View Article and Find Full Text PDFThree-dimensional (3D) imaging is widely utilized in various applications, such as light detection, autonomous vehicles, and machine vision. However, conventional 3D imaging systems often rely on bulky optical components. Metasurfaces, as next-generation optical devices, possess flexible wavefront modulation capabilities and excellent combination with computer vision algorithms.
View Article and Find Full Text PDFBiomed Pharmacother
October 2024
Department of Spine Surgery, Ganzhou People's Hospital, 16 Meiguan Avenue, Ganzhou, Jiangxi Province 341000, PR China; Department of Spine Surgery, The Affiliated Ganzhou Hospital of Nanchang University (Ganzhou Hospital-Nanfang Hospital, Southern Medical University), 16 Meiguan Avenue, Ganzhou, Jiangxi Province 341000, PR China. Electronic address:
Spinal cord injury (SCI) is a central nervous system injury that leads to neurological dysfunction or paralysis, which seriously affects patients' quality of life and causes a heavy social and economic burden. The pathological mechanism of SCI has not been fully revealed, resulting in unsatisfactory clinical treatment. Therefore, more research is urgently needed to reveal its precise pathological mechanism.
View Article and Find Full Text PDFPhys Med Biol
July 2024
Mannheim Institute for Intelligent Systems in Medicine (MIISM), Heidelberg University, Mannheim, Germany.
3D-localization of gamma sources has the potential to improve the outcome of radio-guided surgery. The goal of this paper is to analyze the localization accuracy for point-like sources with a single coded aperture camera.We both simulated and measured a point-like241Am source at 17 positions distributed within the field of view of an experimental gamma camera.
View Article and Find Full Text PDFSpatial, temporal, and spectral resolutions and field-of-view are important characteristics of any imaging system. In most, if not all, it is impossible to change the above characteristics after recording a digital picture, video, or hologram. In recent years, there have been investigations on the possibilities to change the above characteristics post-recording.
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