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X-ray phase contrast imaging can provide improved or complementary information to traditional attenuation-based X-ray imaging, making the field a vast and rapidly evolving research subject. X-ray speckle-based imaging (SBI) is one phase-contrast imaging approach that has shown significant potential in providing both high sensitivity and high resolution while using a very simple experimental setup. With the aim of transferring such phase-contrast-based imaging techniques from synchrotron to laboratory X-ray sources, the issue of the deposited radiation dose still remains to be addressed. In this work, we experimentally and quantitatively compare the results from three different SBI phase retrieval algorithms using both phantoms and biological samples in order to infer the optimal configuration. The results obtained using a synchrotron beam suggest that the technique based on optical flow conservation achieves the most accurate retrieval from the lowest number of sample exposures. This constitutes an important step toward the possibility of transferring SBI into the clinic.
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http://dx.doi.org/10.1088/1361-6560/ab87f7 | DOI Listing |
Significance: Stroke is a leading cause of disability worldwide, necessitating rapid and accurate diagnosis to limit irreversible brain damage. However, many advanced imaging modalities (computerized tomography, magnetic resonance imaging) remain inaccessible in remote or resource-constrained settings due to high costs and logistical barriers.
Aim: We aim to evaluate the feasibility of a laser speckle-based technique, coupled with deep learning, for detecting simulated stroke conditions in a tissue phantom.
Sensors (Basel)
April 2025
Department of Optics, Faculty of Physics, Complutense University of Madrid, Pl. de las Ciencias 1, 28040 Madrid, Spain.
Multimodal imaging is valuable because it can provide additional information beyond that obtained from a conventional bright-field (BF) image and can be implemented with a widely available device. In this paper, we investigate the implementation of speckle-based transmission (T) and dark-field (DF) imaging in a laboratory X-ray setup to confirm its usefulness for material analysis. Three methods for recovering T and DF images were applied to a sample composed of six materials: plastic, nylon, cardboard, cork, expanded polystyrene and foam with different absorption and scattering properties.
View Article and Find Full Text PDFA key contribution to X-ray dark-field (XDF) contrast is the diffusion of X-rays by sample structures smaller than the imaging system's spatial resolution; this is related to position-dependent small-angle X-ray scattering. However, some experimental XDF techniques have reported that XDF contrast is also generated by resolvable sample edges. Speckle-based X-ray imaging (SBXI) extracts the XDF by analyzing sample-imposed changes to a reference speckle pattern's visibility.
View Article and Find Full Text PDFSpeckle-based X-ray imaging (SBI) is a phase-contrast method developed at and for highly coherent X-ray sources, such as synchrotrons, to increase the contrast of weakly absorbing objects. Consequently, it complements the conventional attenuation-based X-ray imaging. Meanwhile, attempts to establish SBI at less coherent laboratory sources have been performed, ranging from liquid metal-jet X-ray sources to microfocus X-ray tubes.
View Article and Find Full Text PDFSci Rep
October 2024
School of Natural Sciences, Physics, University of Galway, Galway, Ireland.