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Optical systems capable of three-dimensional transmission imaging are considered; these systems employ a conventional tomographic setup with an added linear shift-invariant optical system between the sample and the detector. A theoretical analysis is presented of image formation and sample reconstruction in such systems, examples of which include diffraction tomography and phase-contrast tomography with the use of analyzer crystals. An example is introduced in which the image is obtained by scanning the beam along the line orthogonal to the optic axis and to the axis of rotation with a one-dimensional slit or grating parallel to the rotation axis. We show that under certain conditions the proposed system may allow quantitative local (region-of-interest) tomography.
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http://dx.doi.org/10.1364/josaa.24.002230 | DOI Listing |
In this study, a shift-invariant optical pattern classification system is proposed. Optical machine learning systems have been widely studied as processors with massive parallel computing and low power consumption. Conventional optical systems used for pattern classification require diffractive optical elements with microscale surface structures or lens systems.
View Article and Find Full Text PDFIEEE Trans Med Imaging
March 2025
Score-based diffusion models are new and powerful tools for image generation. They are based on a forward stochastic process where an image is degraded with additive white noise and optional input scaling. A neural network can be trained to estimate the time-dependent score function, and used to run the reverse-time stochastic process to generate new samples from the training image distribution.
View Article and Find Full Text PDFBiostatistics
December 2024
Division of Biostatistics and Health Data Science, University of Minnesota, 2221 University Ave SE, Minneapolis, MN 55414, United States.
There is still more to learn about the pathobiology of coronavirus disease (COVID-19) despite 4 years of the pandemic. A multiomics approach offers a comprehensive view of the disease and has the potential to yield deeper insight into the pathogenesis of the disease. Previous multiomics integrative analysis and prediction studies for COVID-19 severity and status have assumed simple relationships (ie linear relationships) between omics data and between omics and COVID-19 outcomes.
View Article and Find Full Text PDFNat Commun
January 2025
Research Laboratory of Electronics, MIT, Cambridge, MA, USA.
Three-dimensional subcellular imaging is essential for biomedical research, but the diffraction limit of optical microscopy compromises axial resolution, hindering accurate three-dimensional structural analysis. This challenge is particularly pronounced in label-free imaging of thick, heterogeneous tissues, where assumptions about data distribution (e.g.
View Article and Find Full Text PDFPhys Med Biol
July 2024
LRCB Dutch Expert Centre for Screening, Nijmegen, The Netherlands.
We propose a nonparametric figure of merit, the contrast equivalent distance CED, to measure contrast directly from clinical images.A relative brightness distanceis calculated by making use of the order statistic of the pixel values. By multiplyingwith the grey value range, the mean brightness distance MBD is obtained.
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