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A linear accelerator has three independent axes that are nominally intersecting at the isocenter. Modern treatment techniques require the coincidence of these axes to lie within a 1-mm diameter sphere. A solution to verify this requirement is to wrap a film on a cylindrical surface, align the cylinder to the linac's isocenter and gantry axis, and take multiple exposures of slits, rotating either the gantry, collimator, or couch between exposures. The resulting exposure pattern is the 3D equivalent of the 2D star shot and encodes sufficient information to determine each axis' position in 3D. Moreover, this method uses a single sheet 8"x10" film, a standard film scanner, and a phantom that can be readily built in-house, making a practical solution to this 3D-measurement problem.
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http://dx.doi.org/10.1002/acm2.13623 | DOI Listing |
Neural Netw
August 2025
School of Advanced Technology, Xi'an Jiaotong-Liverpool University, Suzhou, 215123, China. Electronic address:
Class-agnostic counting is increasingly prevalent in industrial and agricultural applications. However, most deployable methods rely on density maps, which (1) struggle with background interference in complex scenes, and (2) fail to provide precise object locations, limiting downstream usability. The advancement of class-agnostic counting is hindered by suboptimal model designs and the lack of datasets with bounding box annotations.
View Article and Find Full Text PDFKnowledge of a detection system's point-spread function (PSF) allows improving image resolution by deconvolving this PSF. The slanted-edge or Siemens-star approaches are commonly used to retrieve the PSF. The latter retrieves the PSF with a poor angular resolution and requires an intricate, sometimes expensive test pattern.
View Article and Find Full Text PDFMed Image Anal
July 2025
Department of Population Health Sciences, Weill Cornell Medicine, NY, USA. Electronic address:
The CXR-LT series is a community-driven initiative designed to enhance lung disease classification using chest X-rays (CXR). It tackles challenges in open long-tailed lung disease classification and enhances the measurability of state-of-the-art techniques. The first event, CXR-LT 2023, aimed to achieve these goals by providing high-quality benchmark CXR data for model development and conducting comprehensive evaluations to identify ongoing issues impacting lung disease classification performance.
View Article and Find Full Text PDFArXiv
June 2025
Department of Population Health Sciences, Weill Cornell Medicine, New York, USA.
The CXR-LT series is a community-driven initiative designed to enhance lung disease classification using chest X-rays (CXR). It tackles challenges in open long-tailed lung disease classification and enhances the measurability of state-of-the-art techniques. The first event, CXR-LT 2023, aimed to achieve these goals by providing high-quality benchmark CXR data for model development and conducting comprehensive evaluations to identify ongoing issues impacting lung disease classification performance.
View Article and Find Full Text PDFPhotonics Res
April 2025
Department of Biomedical Engineering, University of California, Davis, 451 Health Sciences Dr., Davis, California 95616, USA.
Light penetration depth in biological tissue is limited by tissue scattering. Correcting scattering becomes particularly challenging in scenarios with limited photon availability and when access to the transmission side of the scattering tissue is not possible. Here, we introduce, to our knowledge, a new two-photon microscopy system with Fourier-domain intensity coupling for scattering correction (2P-FOCUS).
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