Phase-contrast X-ray computed tomography of non-formalin fixed biological objects

Phase-contrast synchrotron-based X-ray imaging using an X-ray interferometer provides high sensitivity and high spatial resolution, and it has the ability to depict the fine morphological structures of biological soft tissues, including tumors. In this study, we quantitatively compared phase-contrast synchrotron-based X-ray computed tomography images and images of histopathological hematoxylin-eosin-stained sections of spontaneously occurring rat testicular tumors that contained different types of cells. The absolute densities measured on the phase-contrast synchrotron-based X-ray computed tomography images correlated well with the densities of the nuclear chromatin in the histological images, thereby demonstrating the ability of phase-contrast synchrotron-based X-ray imaging using an X-ray interferometer to reliably identify the characteristics of cancer cells within solid soft tissue tumors. In addition, 3-dimensional synchrotron-based phase-contrast X-ray computed tomography enables screening for different structures within tumors, such as solid, cystic, and fibrous tissues, and blood clots, from any direction and with a spatial resolution down to 26 μm. Thus, phase-contrast synchrotron-based X-ray imaging using an X-ray interferometer shows potential for being useful in preclinical cancer research by providing the ability to depict the characteristics of tumor cells and by offering 3-dimensional information capabilities.

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Image segmentation of nanoscale Zernike phase contrast X-ray computed tomography images

Journal of Applied Physics ◽

10.1063/1.4919835 ◽

2015 ◽

Vol 117 (18) ◽

pp. 183102 ◽

Cited By ~ 15

Author(s):

Arjun S. Kumar ◽

Pratiti Mandal ◽

Yongjie Zhang ◽

Shawn Litster

Keyword(s):

Computed Tomography ◽

Image Segmentation ◽

Phase Contrast ◽

X Ray ◽

Computed Tomography Images ◽

X Ray Computed

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White matter imaging of ethanol-fixed rat brain by phase-contrast X-ray computed tomography

Acta Radiologica ◽

10.1177/02841851211030776 ◽

2021 ◽

pp. 028418512110307

Author(s):

Thet-Thet- Lwin ◽

Akio Yoneyama ◽

Shogo Kokubo ◽

Hiroko Maruyama ◽

Kazuyuki Hyodo ◽

...

Keyword(s):

White Matter ◽

Phase Contrast ◽

Three Dimensional ◽

Image Contrast ◽

Cerebral White Matter ◽

Tissue Fixation ◽

X Ray ◽

Density Values ◽

X Ray Computed ◽

Formalin Fixed

Background Phase-contrast X-ray computed tomography imaging (PCI) based on crystal X-ray interferometry can detect minute density differences within biological soft tissues without contrast agents. Ethanol fixation yields increased tissue-background density differences due to the dehydrating and delipidifying effects of ethanol. Purpose To obtain high image contrast of cerebral white matter structures in PCI, tissue fixation using ethanol and routinely used formalin have been examined. Material and Methods Ethanol-fixed (EF) (n = 4) and formalin-fixed (FF) (n = 4) rat brains were imaged by crystal X-ray interferometry-based PCI. Tissue staining/microscopy was also performed for histological comparison and myelin density evaluation. Three-dimensional white matter tract images were reconstructed. Results Superior image contrast was obtained in the images of EF brains (EF images) compared to those of formalin-fixed brains (FF images), particularly for white matter structures. Significant density differences between the white matter structures and hippocampus ( P < 0.01)/thalamus ( P < 0.001) were observed in the EF, but not FF, images. Ethanol fixation enhanced the image contrast of white matter tracts by approximately sixfold compared to formalin fixation, and close agreement (r2 = 0.97; P < 0.05) between the density values on the CT images and the myelin density values in histological images was observed for the EF brains. Three-dimensional reconstruction of the white matter tracts was possible from the EF images, but not FF images. Conclusion Ethanol fixation resulted in marked contrast enhancement of cerebral white matter structures in PCI. Thus, high-resolution PCI using ethanol for tissue fixation could be valuable for experimental neurological studies and postmortem neuropathology evaluation.

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Testicular seminoma in the aged rat visualized by phase-contrast X-ray computed tomography

Acta Radiologica Open ◽

10.1177/2058460118806657 ◽

2018 ◽

Vol 7 (10) ◽

pp. 205846011880665

Author(s):

Thet-Thet-Lwin ◽

Akio Yoneyama ◽

Motoki Imai ◽

Hiroko Maruyama ◽

Kazuyuki Hyodo ◽

...

Keyword(s):

Computed Tomography ◽

Phase Contrast ◽

Morphological Characteristics ◽

Cellular Structures ◽

Image Generation ◽

Testicular Seminoma ◽

Aged Rat ◽

X Ray ◽

Cystic Changes ◽

X Ray Computed

Spontaneously growing testicular seminoma in the aged rat was imaged by one of the most sensitive imaging modalities, namely, phase-contrast X-ray computed tomography (CT) with crystal X-ray interferometry. Phase-contrast X-ray CT clearly depicted the detailed inner structures of the tumor and provided 20× magnified images compared to light-microscopic images. Phase-contrast X-ray CT images are generated based on density variations in the object, whereas pathological images are based on differentiation of cellular structures, such as the cellular nuclei and cytoplasm. The mechanism of image generation differs between the two techniques: phase-contrast X-ray CT detects even minute differences in the density among pathological structures, depending, for example, on the number and sizes of the nuclei, variations of the cytoplasmic components, and presence/absence of fibrous septa, cystic changes, and hemorrhage. Thus, phase-contrast X-ray CT with a spatial resolution of 26 µm might allow prediction of the morphological characteristics of a tumor even before histopathological processing.

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