Computer simulations of X-ray phase-contrast images and microtomographic observation of tubules in dentin

2020 ◽  
Vol 27 (2) ◽  
pp. 462-467
Author(s):  
T. S. Argunova ◽  
V. G. Kohn ◽  
J.-H. Lim ◽  
Z. V. Gudkina ◽  
E. D. Nazarova

An investigation of the problems of X-ray imaging of dentinal tubules is presented. Two main points are addressed. In the first part of this paper, the problem of computer simulating tubule images recorded in a coherent synchrotron radiation (SR) beam has been discussed. A phantom material which involved a two-dimensional lattice of the tubules with parameters similar to those of dentin was considered. By a comparative examination of two approximations, it was found that the method of phase-contrast imaging is valid if the number of tubules along the beam is less than 100. Calculated images from a lattice of 50 × 50 tubules are periodic in free space but depend strongly on the distance between the specimen and the detector. In the second part, SR microtomographic experiments with millimetre-sized dentin samples in a partially coherent beam have been described. Tomograms were reconstructed from experimental projections using a technique for incoherent radiation. The main result of this part is the three-dimensional rendering of the directions of the tubules in a volume of the samples. Generation of the directions is possible because a tomogram shows the positions of the tubules. However, a detailed tubule cross-section structure cannot be restored.

2021 ◽  
Vol 11 (7) ◽  
pp. 2971
Author(s):  
Siwei Tao ◽  
Congxiao He ◽  
Xiang Hao ◽  
Cuifang Kuang ◽  
Xu Liu

Numerous advances have been made in X-ray technology in recent years. X-ray imaging plays an important role in the nondestructive exploration of the internal structures of objects. However, the contrast of X-ray absorption images remains low, especially for materials with low atomic numbers, such as biological samples. X-ray phase-contrast images have an intrinsically higher contrast than absorption images. In this review, the principles, milestones, and recent progress of X-ray phase-contrast imaging methods are demonstrated. In addition, prospective applications are presented.


2015 ◽  
Vol 22 (6) ◽  
pp. 1531-1539 ◽  
Author(s):  
A. K. Agrawal ◽  
B. Singh ◽  
Y. S. Kashyap ◽  
M. Shukla ◽  
P. S. Sarkar ◽  
...  

A full-field hard X-ray imaging beamline (BL-4) was designed, developed, installed and commissioned recently at the Indus-2 synchrotron radiation source at RRCAT, Indore, India. The bending-magnet beamline is operated in monochromatic and white beam mode. A variety of imaging techniques are implemented such as high-resolution radiography, propagation- and analyzer-based phase contrast imaging, real-time imaging, absorption and phase contrast tomographyetc. First experiments on propagation-based phase contrast imaging and micro-tomography are reported.


2010 ◽  
Vol 6 (6) ◽  
pp. 740-743 ◽  
Author(s):  
Renaud Boistel ◽  
Anthony Herrel ◽  
Gheylen Daghfous ◽  
Paul-Antoine Libourel ◽  
Elodie Boller ◽  
...  

Chamaeleons are well known for their unique suite of morphological adaptations. Whereas most chamaeleons are arboreal and have long tails, which are used during arboreal acrobatic manoeuvres, Malagasy dwarf chamaeleons ( Brookesia ) are small terrestrial lizards with relatively short tails. Like other chamaeleons, Brookesia have grasping feet and use these to hold on to narrow substrates. However, in contrast to other chamaeleons, Brookesia place the tail on the substrate when walking on broad substrates, thus improving stability. Using three-dimensional synchrotron X-ray phase-contrast imaging, we demonstrate a set of unique specializations in the tail associated with the use of the tail during locomotion. Additionally, our imaging demonstrates specializations of the inner ear that may allow these animals to detect small accelerations typical of their slow, terrestrial mode of locomotion. These data suggest that the evolution of a terrestrial lifestyle in Brookesia has gone hand-in-hand with the evolution of a unique mode of locomotion and a suite of morphological adaptations allowing for stable locomotion on a wide array of substrates.


2020 ◽  
Author(s):  
Qiang Tao ◽  
Chen-Chen Gao ◽  
Xue-Hong Tong ◽  
Shizhen Yuan ◽  
Tian-tian Wang ◽  
...  

Abstract Objectives This article shows an imaging method of the stomach that does not use imaging agents. X-ray phase-contrast images of different stages of gastric development were taken using X-ray in-line phase-contrast imaging (XILPCI). The aim of the study was to demonstrate that XILPCI is a micron imaging method for gastric structures. Methods The stomachs of 4-, 6- and 12-week-old rats were removed and cleaned. XILPCI has 1000 times greater soft tissue contrast than that of X-ray traditional absorption radiography. The projection images of the rats’ stomachs were recorded by an XILPCI charge coupled device (CCD) at 9 μm image resolution. Results The X-ray in-line phase-contrast images of the different stages of rat gastric specimens clearly showed the gastric architectures and the details of the gastroduodenal region. 3-dimensional stomach anatomical structure images were reconstruction. Conclusion The reconstructed gastric 3D images can clearly display the internal structure of the stomach. XILPCI may be a useful method for medical research in the future. Keywords: Synchrotron radiation phase-contrast imaging, 3-dimensional gastric structure images


Author(s):  
Farid H. Omoumi ◽  
Muhammad U. Ghani ◽  
Molly D. Wong ◽  
Yuchen Qiu ◽  
Yuhua Li ◽  
...  

2008 ◽  
Vol 2008 ◽  
pp. 1-8 ◽  
Author(s):  
Ming Jiang ◽  
Christopher Lee Wyatt ◽  
Ge Wang

X-ray imaging is of paramount importance for clinical and preclinical imaging but it is fundamentally restricted by the attenuation-based contrast mechanism, which has remained essentially the same since Roentgen's discovery a century ago. Recently, based on the Talbot effect, groundbreaking work was reported using 1D gratings for X-ray phase-contrast imaging with a hospital-grade X-ray tube instead of a synchrotron or microfocused source. In this paper, we report an extension using 2D gratings that reduces the imaging time and increases the accuracy and robustness of phase retrieval compared to current grating-based phase-contrast techniques. Feasibility is demonstrated via numerical simulation.


2014 ◽  
Vol 21 (4) ◽  
pp. 790-794 ◽  
Author(s):  
Ismo Vartiainen ◽  
Martin Warmer ◽  
Dennis Goeries ◽  
Eva Herker ◽  
Rudolph Reimer ◽  
...  

X-ray microscopy is a commonly used method especially in material science application, where the large penetration depth of X-rays is necessary for three-dimensional structural studies of thick specimens with high-Zelements. In this paper it is shown that full-field X-ray microscopy at 6.2 keV can be utilized for imaging of biological specimens with high resolution. A full-field Zernike phase-contrast microscope based on diffractive optics is used to study lipid droplet formation in hepatoma cells. It is shown that the contrast of the images is comparable with that of electron microscopy, and even better contrast at tender X-ray energies between 2.5 keV and 4 keV is expected.


2011 ◽  
Vol 5 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Lu Zhang ◽  
Shuqian Luo

The current imaging methods have a limited ability to visualize microstructures of biological soft tissues. Small lesions cannot be detected at the early stage of the disease. Phase contrast imaging (PCI) is a novel non-invasive imaging technique that can provide high contrast images of soft tissues by the use of X-ray phase shift. It is a new choice in terms of non-invasively revealing soft tissue details. In this study, the lung and hepatic fibrosis models of mice and rats were used to investigate the ability of PCI in microstructures observation of soft tissues. Our results demonstrated that different liver fibrosis stages could be distinguished non-invasively by PCI. The three-dimensional morphology of a segment of blood vessel was constructed. Noteworthy, the blood clot inside the vessel was visualized in three dimensions which provided a precise description of vessel stenosis. Furthermore, the whole lung airways including the alveoli were obtained. We had specifically highlighted its use in the visualization and assessment of the alveoli. To our knowledge, this was the first time for non-invasive alveoli imaging using PCI. This finding may offer a new perspective on the diagnosis of respiratory disease. All the results confirmed that PCI will be a valuable tool in biological soft tissues imaging.


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