scholarly journals X-ray phase-contrast computed tomography visualizes the microstructure and degradation profile of implanted biodegradable scaffolds after spinal cord injury

2015 ◽  
Vol 22 (1) ◽  
pp. 136-142 ◽  
Author(s):  
Kenta Takashima ◽  
Masato Hoshino ◽  
Kentaro Uesugi ◽  
Naoto Yagi ◽  
Shojiro Matsuda ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Spinal Cord ◽  
Tissue Engineering ◽  
Phase Contrast ◽  
Three Dimensional ◽  
Injured Spinal Cord ◽  
X Ray ◽  
Biodegradable Scaffolds ◽  
Cord Injury ◽  
Grating Interferometer

Tissue engineering strategies for spinal cord repair are a primary focus of translational medicine after spinal cord injury (SCI). Many tissue engineering strategies employ three-dimensional scaffolds, which are made of biodegradable materials and have microstructure incorporated with viable cells and bioactive molecules to promote new tissue generation and functional recovery after SCI. It is therefore important to develop an imaging system that visualizes both the microstructure of three-dimensional scaffolds and their degradation process after SCI. Here, X-ray phase-contrast computed tomography imaging based on the Talbot grating interferometer is described and it is shown how it can visualize the polyglycolic acid scaffold, including its microfibres, after implantation into the injured spinal cord. Furthermore, X-ray phase-contrast computed tomography images revealed that degradation occurred from the end to the centre of the braided scaffold in the 28 days after implantation into the injured spinal cord. The present report provides the first demonstration of an imaging technique that visualizes both the microstructure and degradation of biodegradable scaffolds in SCI research. X-ray phase-contrast imaging based on the Talbot grating interferometer is a versatile technique that can be used for a broad range of preclinical applications in tissue engineering strategies.

scholarly journals Spinal Cord Repair: From Cells and Tissue Engineering to Extracellular Vesicles

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1872
Author(s):  
Shaowei Guo ◽  
Idan Redenski ◽  
Shulamit Levenberg
Keyword(s):  
Spinal Cord ◽  
Tissue Engineering ◽  
Extracellular Vesicles ◽  
Functional Recovery ◽  
Three Dimensional ◽  
Therapeutic Modality ◽  
Spinal Cord Tissue ◽  
New Paradigm ◽  
Cord Injury ◽  
Severe Motor

Spinal cord injury (SCI) is a debilitating condition, often leading to severe motor, sensory, or autonomic nervous dysfunction. As the holy grail of regenerative medicine, promoting spinal cord tissue regeneration and functional recovery are the fundamental goals. Yet, effective regeneration of injured spinal cord tissues and promotion of functional recovery remain unmet clinical challenges, largely due to the complex pathophysiology of the condition. The transplantation of various cells, either alone or in combination with three-dimensional matrices, has been intensively investigated in preclinical SCI models and clinical trials, holding translational promise. More recently, a new paradigm shift has emerged from cell therapy towards extracellular vesicles as an exciting “cell-free” therapeutic modality. The current review recapitulates recent advances, challenges, and future perspectives of cell-based spinal cord tissue engineering and regeneration strategies.

Visualization of microvasculature and thrombi by X-ray phase-contrast computed tomography in hepatocellular carcinoma

2016 ◽  
Vol 23 (2) ◽  
pp. 600-605 ◽  
Author(s):  
Jianbo Jian ◽  
Hao Yang ◽  
Xinyan Zhao ◽  
Ruijiao Xuan ◽  
Yujie Zhang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Hepatocellular Carcinoma ◽  
Phase Contrast ◽  
Soft Tissues ◽  
Three Dimensional ◽  
X Ray ◽  
Density Distributions ◽  
Fine Structures ◽  
Tumor Growth And Metastasis ◽  
Micrometer Scale

Visualization of the microvascular network and thrombi in the microvasculature is a key step to evaluating the development of tumor growth and metastasis, and influences treatment selection. X-ray phase-contrast computed tomography (PCCT) is a new imaging technique that can detect minute changes of density and reveal soft tissues discrimination at micrometer-scale resolution. In this study, six human resected hepatocellular carcinoma (HCC) tissues were investigated with PCCT. A histological stain was added to estimate the accuracy of PCCT. The results showed that the fine structures of the microvasculature (measuring 30–100 µm) and thrombi in tiny blood vessels were displayed clearly on imaging the HCC tissues by PCCT. Moreover, density distributions of the thrombi were obtained, which could be reliably used to distinguish malignant from benign thrombi in HCC. In conclusion, PCCT can clearly show the three-dimensional subtle structures of HCC that cannot be detected by conventional absorption-based computed tomography and provides a new method for the imageology of HCC.

Transplantation of collagen sponge-based three-dimensional neural stem cells cultured in the RCCS system facilitate locomotor functional recovery in spinal cord injury animals

2022 ◽  
Author(s):  
Jianwu Dai ◽  
Yunlong Zou ◽  
Yanyun Yin ◽  
Zhifeng Xiao ◽  
Yannan Zhao ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Tissue Engineering ◽  
Stem Cells ◽  
Spinal Cord Injury ◽  
Neural Stem Cells ◽  
Three Dimensional ◽  
Collagen Sponge ◽  
Cellular Functions ◽  
Cord Injury ◽  
Cells Cultured

Numerous studies have indicated that microgravity induces various changes in the cellular functions of neural stem cells (NSCs), and the use of microgravity to culture tissue engineering seed cells for...

scholarly journals Dual energy X-ray absorptiometry of the knee in spinal cord injury: methodology and correlation with quantitative computed tomography

Spinal Cord ◽  
2014 ◽  
Vol 52 (11) ◽  
pp. 821-825 ◽  
Author(s):  
J G McPherson ◽  
W B Edwards ◽  
A Prasad ◽  
K L Troy ◽  
J W Griffith ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Quantitative Computed Tomography ◽  
Dual Energy ◽  
X Ray ◽  
Cord Injury

High-Resolution Radiography for Detecting and Measuring Micron-Scale Features

2004 ◽  
Author(s):  
Daniel H. Morse ◽  
Arlyn J. Antolak ◽  
Bernice E. Mills
Keyword(s):  
Computed Tomography ◽  
Composite Materials ◽  
Phase Contrast ◽  
Three Dimensional ◽  
Conventional Radiography ◽  
Small Scale ◽  
Micro Computed Tomography ◽  
Contrast Imaging ◽  
X Ray ◽  
Projection Radiography

X-ray radiography has long been recognized as a valuable tool for detecting internal features and flaws. Recent developments in microfabrication and composite materials have extended inspection requirements to the resolution limits of conventional radiography. Our work has been directed toward pushing both detection and measurement capabilities to a smaller scale. Until recently, we have used conventional contact radiography, optimized to resolve small features. With the recent purchase of a nano-focus (sub-micron) x-ray source, we are now investigating projection radiography, phase contrast imaging and micro-computed tomography (μ-CT). Projection radiography produces a magnified image that is limited in spatial resolution mainly by the source size, not by film grain size or detector pixel size. Under certain conditions phase contrast can increase the ability to resolve small features such as cracks, especially in materials with low absorption contrast. Micro-computed tomography can provide three-dimensional measurements on a micron scale and has been shown to provide better sensitivity than simple radiographs. We have included applications of these techniques to small-scale measurements not easily made by mechanical or optical means. Examples include void detection in meso-scale nickel MEMS parts, measurement of edge profiles in thick gold lithography masks, and characterization of the distribution of phases in composite materials. Our work, so far, has been limited to film.

Direct three-dimensional imaging for morphological analysis of electrospun fibers with laboratory-based Zernike X-ray phase-contrast computed tomography

2020 ◽  
Vol 115 ◽  
pp. 111045 ◽  
Author(s):  
Cristine Santos de Oliveira ◽  
Adriana Trompetero González ◽  
Tobias Hedtke ◽  
Tobias Kürbitz ◽  
Andreas Heilmann ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Phase Contrast ◽  
Morphological Analysis ◽  
Three Dimensional ◽  
Electrospun Fibers ◽  
Three Dimensional Imaging ◽  
X Ray

scholarly journals Direct information retrieval after 3D reconstruction in grating-based X-ray phase-contrast computed tomography

2018 ◽  
Vol 25 (4) ◽  
pp. 1222-1228 ◽  
Author(s):  
Zhao Wu ◽  
Kun Gao ◽  
Zhili Wang ◽  
Chenxi Wei ◽  
Faiz Wali ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Information Retrieval ◽  
Phase Contrast ◽  
Three Dimensional ◽  
Large Field ◽  
Computational Time ◽  
Imaging Method ◽  
Phase Reconstruction ◽  
Phase Information ◽  
X Ray

Grating-based X-ray differential phase-contrast imaging has attracted a great amount of attention and has been considered as a potential imaging method in clinical medicine because of its compatibility with the traditional X-ray tube source and the possibility of a large field of view. Moreover, phase-contrast computed tomography provides three-dimensional phase-contrast visualization. Generally, two-dimensional information retrieval performed on every projection is required prior to three-dimensional reconstruction in phase-contrast computed tomography. In this paper, a three-dimensional information retrieval method to separate absorption and phase information directly from two reconstructed images is derived. Theoretical derivations together with numerical simulations have been performed to confirm the feasibility and veracity of the proposed method. The advantages and limitations compared with the reverse projection method are also discussed. Owing to the reduced data size and the absence of a logarithm operation, the computational time for information retrieval is shortened by the proposed method. In addition, the hybrid three-dimensional images of absorption and phase information were reconstructed using an absorption reconstruction algorithm, hence the existing data pre-processing methods and iterative reconstruction algorithms in absorption reconstruction may be utilized in phase reconstruction immediately.

Potential of propagation-based synchrotron X-ray phase-contrast computed tomography for cardiac tissue engineering

2017 ◽  
Vol 24 (4) ◽  
pp. 842-853 ◽  
Author(s):  
Mohammad Izadifar ◽  
Paul Babyn ◽  
Dean Chapman ◽  
Michael E. Kelly ◽  
Xiongbiao Chen
Keyword(s):  
Computed Tomography ◽  
Tissue Engineering ◽  
Soft Tissue ◽  
Ct Scan ◽  
Phase Contrast ◽  
Cardiac Tissue ◽  
Cardiac Tissue Engineering ◽  
X Ray ◽  
Imaging Quality ◽  
Scan Time

Hydrogel-based cardiac tissue engineering offers great promise for myocardial infarction repair. The ability to visualize engineered systemsin vivoin animal models is desired to monitor the performance of cardiac constructs. However, due to the low density and weak X-ray attenuation of hydrogels, conventional radiography and micro-computed tomography are unable to visualize the hydrogel cardiac constructs upon their implantation, thus limiting their use in animal systems. This paper presents a study on the optimization of synchrotron X-ray propagation-based phase-contrast imaging computed tomography (PCI-CT) for three-dimensional (3D) visualization and assessment of the hydrogel cardiac patches. First, alginate hydrogel was 3D-printed into cardiac patches, with the pores filled by fibrin. The hydrogel patches were then surgically implanted on rat hearts. A week after surgery, the hearts including patches were excised and embedded in a soft-tissue-mimicking gel for imaging by using PCI-CT at an X-ray energy of 25 keV. During imaging, the sample-to-detector distances, CT-scan time and the region of interest (ROI) were varied and examined for their effects on both imaging quality and radiation dose. The results showed that phase-retrieved PCI-CT images provided edge-enhancement fringes at a sample-to-detector distance of 147 cm that enabled visualization of anatomical and microstructural features of the myocardium and the implanted patch in the tissue-mimicking gel. For visualization of these features, PCI-CT offered a significantly higher performance than the dual absorption-phase and clinical magnetic resonance (3 T) imaging techniques. Furthermore, by reducing the total CT-scan time and ROI, PCI-CT was examined for lowering the effective dose, meanwhile without much loss of imaging quality. In effect, the higher soft tissue contrast and low-dose potential of PCI-CT has been used along with an acceptable overall animal dose to achieve the high spatial resolution needed for cardiac implant visualization. As a result, PCI-CT at the identified imaging parameters offers great potential for 3D assessment of microstructural features of hydrogel cardiac patches.

Three-dimensional visualization of fibrous tissues in cirrhotic rats via X-ray phase-contrast computed tomography with iodine staining

2019 ◽  
Vol 26 (4) ◽  
pp. 1354-1360
Author(s):  
Jianbo Jian ◽  
Xinyan Zhao ◽  
Lili Qin ◽  
Yuqing Zhao ◽  
Mengyu Sun ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Phase Contrast ◽  
Structural Information ◽  
Three Dimensional ◽  
X Ray ◽  
Iodine Staining ◽  
Quantitative Measurements ◽  
Structural Details ◽  
3D Presentation ◽  
Histopathologic Findings

To accurately characterize cirrhosis, knowledge of the 3D fibrous structures is essential. Histology is the gold standard in cirrhosis screening, but it mainly provides structural information in 2D planes and destroys the 3D samples in the process. The aim of this study was to evaluate the potential of X-ray phase-contrast computed tomography (PCCT) with iodine staining for the 3D nondestructive visualization of internal structural details in entire cirrhotic livers with histopathologic correlation. In this study, cirrhotic livers induced by carbon tetrachloride (CCl4) in rats were imaged via PCCT and then histopathologically processed. Characteristics of the cirrhosis, i.e. abnormal nodules surrounded by annular fibrosis, were established and a 3D reconstruction of these structures was also performed via PCCT. Fibrosis area, septal width and nodular size were measured and the correlation for these quantitative measurements between PCCT and histopathologic findings was analyzed. The results showed that fibrous bands, small nodules and angio-architecture in cirrhosis were clearly presented in the PCCT images, with histopathologic findings as standard reference. In comparison with histopathology, PCCT was associated with a very close value for fibrosis area, septal width and nodular size. The quantitative measurements showed a strong correlation between PCCT and histopathology. Additionally, the 3D structures of fibrous bands and microvasculature were presented simultaneously. PCCT provides excellent results in the assessment of cirrhosis characteristics and 3D presentation of these feature structures compared with histopathology. Thus, the technique may serve as an adjunct nondestructive 3D modality for cirrhosis characterization.

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