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Hu Z, Zhang Y, Maiden A. Computational optical sectioning via near-field multi-slice ptychography. OPTICS LETTERS 2024; 49:4839-4842. [PMID: 39207977 DOI: 10.1364/ol.529190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Accepted: 07/30/2024] [Indexed: 09/04/2024]
Abstract
We introduce a method for the computational sectioning of optically thick samples based on a combination of near-field and multi-slice ptychography. The method enables a large field-of-view 3D phase imaging of samples that is an order of magnitude thicker than the depth of field of bright-field microscopy. An axial resolution for these thick samples is maintained in the presence of multiple scattering, revealing a complex structure beyond the depth of the field limit. In this Letter, we describe the new, to the best of our knowledge, approach and demonstrate its effectiveness using a range of samples with diverse thicknesses and optical properties.
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2
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Aidukas T, Phillips NW, Diaz A, Poghosyan E, Müller E, Levi AFJ, Aeppli G, Guizar-Sicairos M, Holler M. High-performance 4-nm-resolution X-ray tomography using burst ptychography. Nature 2024; 632:81-88. [PMID: 39085541 DOI: 10.1038/s41586-024-07615-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 05/28/2024] [Indexed: 08/02/2024]
Abstract
Advances in science, medicine and engineering rely on breakthroughs in imaging, particularly for obtaining multiscale, three-dimensional information from functional systems such as integrated circuits or mammalian brains. Achieving this goal often requires combining electron- and photon-based approaches. Whereas electron microscopy provides nanometre resolution through serial, destructive imaging of surface layers1, ptychographic X-ray computed tomography2 offers non-destructive imaging and has recently achieved resolutions down to seven nanometres for a small volume3. Here we implement burst ptychography, which overcomes experimental instabilities and enables much higher performance, with 4-nanometre resolution at a 170-times faster acquisition rate, namely, 14,000 resolution elements per second. Another key innovation is tomographic back-propagation reconstruction4, allowing us to image samples up to ten times larger than the conventional depth of field. By combining the two innovations, we successfully imaged a state-of-the-art (seven-nanometre node) commercial integrated circuit, featuring nanostructures made of low- and high-density materials such as silicon and metals, which offer good radiation stability and contrast at the selected X-ray wavelength. These capabilities enabled a detailed study of the chip's design and manufacturing, down to the level of individual transistors. We anticipate that the combination of nanometre resolution and higher X-ray flux at next-generation X-ray sources will have a revolutionary impact in fields ranging from electronics to electrochemistry and neuroscience.
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Affiliation(s)
| | - Nicholas W Phillips
- Paul Scherrer Institute, Villigen, Switzerland
- Mineral Resources, CSIRO, Clayton, Victoria, Australia
| | - Ana Diaz
- Paul Scherrer Institute, Villigen, Switzerland
| | | | | | - A F J Levi
- Department of Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, USA
| | - Gabriel Aeppli
- Paul Scherrer Institute, Villigen, Switzerland
- Department of Physics, Eidgenössische Technische Hochschule Zürich (ETH Zürich), Zurich, Switzerland
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Quantum Center, Eidgenössische Technische Hochschule Zürich (ETH Zürich), Zurich, Switzerland
| | - Manuel Guizar-Sicairos
- Paul Scherrer Institute, Villigen, Switzerland
- Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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3
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Xian RP, Brunet J, Huang Y, Wagner WL, Lee PD, Tafforeau P, Walsh CL. A closer look at high-energy X-ray-induced bubble formation during soft tissue imaging. JOURNAL OF SYNCHROTRON RADIATION 2024; 31:566-577. [PMID: 38682274 DOI: 10.1107/s160057752400290x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 04/02/2024] [Indexed: 05/01/2024]
Abstract
Improving the scalability of tissue imaging throughput with bright, coherent X-rays requires identifying and mitigating artifacts resulting from the interactions between X-rays and matter. At synchrotron sources, long-term imaging of soft tissues in solution can result in gas bubble formation or cavitation, which dramatically compromises image quality and integrity of the samples. By combining in-line phase-contrast imaging with gas chromatography in real time, we were able to track the onset and evolution of high-energy X-ray-induced gas bubbles in ethanol-embedded soft tissue samples for tens of minutes (two to three times the typical scan times). We demonstrate quantitatively that vacuum degassing of the sample during preparation can significantly delay bubble formation, offering up to a twofold improvement in dose tolerance, depending on the tissue type. However, once nucleated, bubble growth is faster in degassed than undegassed samples, indicating their distinct metastable states at bubble onset. Gas chromatography analysis shows increased solvent vaporization concurrent with bubble formation, yet the quantities of dissolved gasses remain unchanged. By coupling features extracted from the radiographs with computational analysis of bubble characteristics, we uncover dose-controlled kinetics and nucleation site-specific growth. These hallmark signatures provide quantitative constraints on the driving mechanisms of bubble formation and growth. Overall, the observations highlight bubble formation as a critical yet often overlooked hurdle in upscaling X-ray imaging for biological tissues and soft materials and we offer an empirical foundation for their understanding and imaging protocol optimization. More importantly, our approaches establish a top-down scheme to decipher the complex, multiscale radiation-matter interactions in these applications.
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Affiliation(s)
- R Patrick Xian
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Joseph Brunet
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Yuze Huang
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Willi L Wagner
- Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
| | - Peter D Lee
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Paul Tafforeau
- European Synchrotron Radiation Facility, Grenoble, France
| | - Claire L Walsh
- Department of Mechanical Engineering, University College London, London, United Kingdom
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Babu AV, Zhou T, Kandel S, Bicer T, Liu Z, Judge W, Ching DJ, Jiang Y, Veseli S, Henke S, Chard R, Yao Y, Sirazitdinova E, Gupta G, Holt MV, Foster IT, Miceli A, Cherukara MJ. Deep learning at the edge enables real-time streaming ptychographic imaging. Nat Commun 2023; 14:7059. [PMID: 37923741 PMCID: PMC10624836 DOI: 10.1038/s41467-023-41496-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 09/06/2023] [Indexed: 11/06/2023] Open
Abstract
Coherent imaging techniques provide an unparalleled multi-scale view of materials across scientific and technological fields, from structural materials to quantum devices, from integrated circuits to biological cells. Driven by the construction of brighter sources and high-rate detectors, coherent imaging methods like ptychography are poised to revolutionize nanoscale materials characterization. However, these advancements are accompanied by significant increase in data and compute needs, which precludes real-time imaging, feedback and decision-making capabilities with conventional approaches. Here, we demonstrate a workflow that leverages artificial intelligence at the edge and high-performance computing to enable real-time inversion on X-ray ptychography data streamed directly from a detector at up to 2 kHz. The proposed AI-enabled workflow eliminates the oversampling constraints, allowing low-dose imaging using orders of magnitude less data than required by traditional methods.
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Affiliation(s)
- Anakha V Babu
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
- KLA Corporation, Ann Arbor, MI, USA
| | - Tao Zhou
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | - Saugat Kandel
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | - Tekin Bicer
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | - Zhengchun Liu
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | - William Judge
- Department of Chemistry, University of Illinois, Chicago, IL, USA
| | - Daniel J Ching
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | - Yi Jiang
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | - Sinisa Veseli
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | - Steven Henke
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | - Ryan Chard
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | - Yudong Yao
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | | | | | - Martin V Holt
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | - Ian T Foster
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA
| | - Antonino Miceli
- Argonne National Laboratory, 9700 S Cass Ave, Lemont, IL, USA.
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Kandel S, Zhou T, Babu AV, Di Z, Li X, Ma X, Holt M, Miceli A, Phatak C, Cherukara MJ. Demonstration of an AI-driven workflow for autonomous high-resolution scanning microscopy. Nat Commun 2023; 14:5501. [PMID: 37679317 PMCID: PMC10485018 DOI: 10.1038/s41467-023-40339-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 07/19/2023] [Indexed: 09/09/2023] Open
Abstract
Modern scanning microscopes can image materials with up to sub-atomic spatial and sub-picosecond time resolutions, but these capabilities come with large volumes of data, which can be difficult to store and analyze. We report the Fast Autonomous Scanning Toolkit (FAST) that addresses this challenge by combining a neural network, route optimization, and efficient hardware controls to enable a self-driving experiment that actively identifies and measures a sparse but representative data subset in lieu of the full dataset. FAST requires no prior information about the sample, is computationally efficient, and uses generic hardware controls with minimal experiment-specific wrapping. We test FAST in simulations and a dark-field X-ray microscopy experiment of a WSe2 film. Our studies show that a FAST scan of <25% is sufficient to accurately image and analyze the sample. FAST is easy to adapt for any scanning microscope; its broad adoption will empower general multi-level studies of materials evolution with respect to time, temperature, or other parameters.
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Affiliation(s)
- Saugat Kandel
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA.
| | - Tao Zhou
- Nanoscience and Technology Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | | | - Zichao Di
- Mathematics and Computer Science, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Xinxin Li
- Nanoscience and Technology Division, Argonne National Laboratory, Lemont, IL, 60439, USA
- Consortium for Advanced Science and Engineering, University of Chicago, Chicago, Illinois, 60637, USA
| | - Xuedan Ma
- Nanoscience and Technology Division, Argonne National Laboratory, Lemont, IL, 60439, USA
- Consortium for Advanced Science and Engineering, University of Chicago, Chicago, Illinois, 60637, USA
| | - Martin Holt
- Nanoscience and Technology Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Antonino Miceli
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Charudatta Phatak
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Mathew J Cherukara
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA.
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Hu Z, Zhang Y, Li P, Batey D, Maiden A. Near-field multi-slice ptychography: quantitative phase imaging of optically thick samples with visible light and X-rays. OPTICS EXPRESS 2023; 31:15791-15809. [PMID: 37157672 DOI: 10.1364/oe.487002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Ptychography is a form of lens-free coherent diffractive imaging now used extensively in electron and synchrotron-based X-ray microscopy. In its near-field implementation, it offers a route to quantitative phase imaging at an accuracy and resolution competitive with holography, with the added advantages of extended field of view and blind deconvolution of the illumination beam profile from the sample image. In this paper we show how near-field ptychography can be combined with a multi-slice model, adding to this list of advantages the unique ability to recover high-resolution phase images of larger samples, whose thickness places them beyond the depth of field of alternative methods.
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Vacek E, Preissner C, Deng J, Jacobsen C. Fast scanning in x-ray microscopy: the effects of offset in the central stop position. APPLIED OPTICS 2022; 61:6811-6818. [PMID: 36255769 DOI: 10.1364/ao.469319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 06/16/2023]
Abstract
Scanning of lightweight circular diffractive optics, separate from central stops and apertures, is emerging as an approach to exploit advances in synchrotron x-ray sources. We consider the effects in a scanning microscope of offsets between the optic and its central stop and find that scan ranges of up to about half the diameter of the optic are possible with only about a 10% increase in the focal spot width. For large scanning ranges, we present criteria for the working distance between the last aperture and the specimen to be imaged.
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Deng J, Yao Y, Jiang Y, Chen S, Mooney TM, Klug JA, Marin FS, Roehrig C, Yue K, Preissner C, Cai Z, Lai B, Vogt S. High-resolution ptychographic imaging enabled by high-speed multi-pass scanning. OPTICS EXPRESS 2022; 30:26027-26042. [PMID: 36236801 DOI: 10.1364/oe.460232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 06/18/2022] [Indexed: 06/16/2023]
Abstract
As a coherent diffraction imaging technique, ptychography provides high-spatial resolution beyond Rayleigh's criterion of the focusing optics, but it is also sensitively affected by the decoherence coming from the spatial and temporal variations in the experiment. Here we show that high-speed ptychographic data acquisition with short exposure can effectively reduce the impact from experimental variations. To reach a cumulative dose required for a given resolution, we further demonstrate that a continuous multi-pass scan via high-speed ptychography can achieve high-resolution imaging. This low-dose scan strategy is shown to be more dose-efficient, and has potential for radiation-sensitive sample studies and time-resolved imaging.
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Xian RP, Walsh CL, Verleden SE, Wagner WL, Bellier A, Marussi S, Ackermann M, Jonigk DD, Jacob J, Lee PD, Tafforeau P. A multiscale X-ray phase-contrast tomography dataset of a whole human left lung. Sci Data 2022; 9:264. [PMID: 35654864 PMCID: PMC9163096 DOI: 10.1038/s41597-022-01353-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 05/03/2022] [Indexed: 11/09/2022] Open
Abstract
Technological advancements in X-ray imaging using bright and coherent synchrotron sources now allows the decoupling of sample size and resolution while maintaining high sensitivity to the microstructures of soft, partially dehydrated tissues. The continuous developments in multiscale X-ray imaging resulted in hierarchical phase-contrast tomography, a comprehensive approach to address the challenge of organ-scale (up to tens of centimeters) soft tissue imaging with resolution and sensitivity down to the cellular level. Using this technique, we imaged ex vivo an entire human left lung at an isotropic voxel size of 25.08 μm along with local zooms down to 6.05-6.5 μm and 2.45-2.5 μm in voxel size. The high tissue contrast offered by the fourth-generation synchrotron source at the European Synchrotron Radiation Facility reveals the complex multiscale anatomical constitution of the human lung from the macroscopic (centimeter) down to the microscopic (micrometer) scale. The dataset provides comprehensive organ-scale 3D information of the secondary pulmonary lobules and delineates the microstructure of lung nodules with unprecedented detail.
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Affiliation(s)
- R Patrick Xian
- Department of Mechanical Engineering, University College London, London, UK.
| | - Claire L Walsh
- Department of Mechanical Engineering, University College London, London, UK
| | - Stijn E Verleden
- Antwerp Surgical Training, Anatomy and Research Centre (ASTARC), University of Antwerp, Wilrijk, Belgium
| | - Willi L Wagner
- Department of Diagnostic and Interventional Radiology, University Hospital Heidelberg, Heidelberg, Germany
- Translational Lung Research Centre Heidelberg (TLRC), German Lung Research Centre (DZL), Heidelberg, Germany
| | - Alexandre Bellier
- Laboratoire d'Anatomie des Alpes Françaises (LADAF), Université Grenoble Alpes, Grenoble, France
| | - Sebastian Marussi
- Department of Mechanical Engineering, University College London, London, UK
| | - Maximilian Ackermann
- Institute of Pathology and Molecular Pathology, Helios University Clinic Wuppertal, University of Witten/Herdecke, Wuppertal, Germany
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Danny D Jonigk
- Institute of Pathology, Hannover Medical School, Hannover, Germany
- Biomedical Research in End-stage and Obstructive Lung Disease Hannover (BREATH), German Lung Research Centre (DZL), Hannover, Germany
| | - Joseph Jacob
- Centre for Medical Image Computing, University College London, London, UK
- Department of Radiology, University College London Hospitals NHS Foundation Trust, London, UK
| | - Peter D Lee
- Department of Mechanical Engineering, University College London, London, UK.
| | - Paul Tafforeau
- European Synchrotron Radiation Facility, Grenoble, France.
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Jones MWM, van Riessen GA, Phillips NW, Schrank CE, Hinsley GN, Afshar N, Reinhardt J, de Jonge MD, Kewish CM. High-speed free-run ptychography at the Australian Synchrotron. JOURNAL OF SYNCHROTRON RADIATION 2022; 29:480-487. [PMID: 35254312 PMCID: PMC8900864 DOI: 10.1107/s1600577521012856] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Over the last decade ptychography has progressed rapidly from a specialist ultramicroscopy technique into a mature method accessible to non-expert users. However, to improve scientific value ptychography data must reconstruct reliably, with high image quality and at no cost to other correlative methods. Presented here is the implementation of high-speed ptychography used at the Australian Synchrotron on the XFM beamline, which includes a free-run data collection mode where dead time is eliminated and the scan time is optimized. It is shown that free-run data collection is viable for fast and high-quality ptychography by demonstrating extremely high data rate acquisition covering areas up to 352 000 µm2 at up to 140 µm2 s-1, with 13× spatial resolution enhancement compared with the beam size. With these improvements, ptychography at velocities up to 250 µm s-1 is approaching speeds compatible with fast-scanning X-ray fluorescence microscopy. The combination of these methods provides morphological context for elemental and chemical information, enabling unique scientific outcomes.
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Affiliation(s)
- Michael W. M. Jones
- Central Analytical Research Facility, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Grant A. van Riessen
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia
- Melbourne Centre for Nanofabrication, Clayton, Victoria 3168, Australia
| | - Nicholas W. Phillips
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, United Kingdom
| | - Christoph E. Schrank
- School of Earth and Atmospheric Sciences, Faculty of Science, Queensland University of Technology, Brisbane, Queensland 4000, Australia
| | - Gerard N. Hinsley
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia
| | - Nader Afshar
- Australian Nuclear Science and Technology Organisation, Australian Synchrotron, Clayton, Victoria 3168, Australia
| | - Juliane Reinhardt
- Australian Nuclear Science and Technology Organisation, Australian Synchrotron, Clayton, Victoria 3168, Australia
| | - Martin D. de Jonge
- Australian Nuclear Science and Technology Organisation, Australian Synchrotron, Clayton, Victoria 3168, Australia
| | - Cameron M. Kewish
- Department of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria 3086, Australia
- Australian Nuclear Science and Technology Organisation, Australian Synchrotron, Clayton, Victoria 3168, Australia
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Virtual histology of an entire mouse brain from formalin fixation to paraffin embedding. Part 1: Data acquisition, anatomical feature segmentation, tracking global volume and density changes. J Neurosci Methods 2021; 364:109354. [PMID: 34529981 DOI: 10.1016/j.jneumeth.2021.109354] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/01/2021] [Accepted: 09/04/2021] [Indexed: 01/14/2023]
Abstract
BACKGROUND Micrometer-resolution neuroimaging with gold-standard conventional histology requires tissue fixation and embedding. The exchange of solvents for the creation of sectionable paraffin blocks modifies tissue density and generates non-uniform brain shrinkage. NEW METHOD We employed synchrotron radiation-based X-ray microtomography for slicing- and label-free virtual histology of the mouse brain at different stages of the standard preparation protocol from formalin fixation via ascending ethanol solutions and xylene to paraffin embedding. Segmentation of anatomical regions allowed us to quantify non-uniform tissue shrinkage. Global and local changes in X-ray absorption gave insight into contrast enhancement for virtual histology. RESULTS The volume of the entire mouse brain was 60%, 56%, and 40% of that in formalin for, respectively, 100% ethanol, xylene, and paraffin. The volume changes of anatomical regions such as the hippocampus, anterior commissure, and ventricles differ from the global volume change. X-ray absorption of the full brain decreased, while local absorption differences increased, resulting in enhanced contrast for virtual histology. These trends were also observed with laboratory microtomography measurements. COMPARISON WITH EXISTING METHODS Microtomography provided sub-10 μm spatial resolution with sufficient density resolution to resolve anatomical structures at each step of the embedding protocol. The spatial resolution of conventional computed tomography and magnetic resonance microscopy is an order of magnitude lower and both do not match the contrast of microtomography over the entire embedding protocol. Unlike feature-to-feature or total volume measurements, our approach allows for calculation of volume change based on segmentation. CONCLUSION We present isotropic micrometer-resolution imaging to quantify morphology and composition changes in a mouse brain during the standard histological preparation. The proposed method can be employed to identify the most appropriate embedding medium for anatomical feature visualization, to reveal the basis for the dramatic X-ray contrast enhancement observed in numerous embedded tissues, and to quantify morphological changes during tissue fixation and embedding.
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