µ-tomographic images of a few soft materials and embedded biological soft tissue at x-ray energies: a new approach based on geometrical considerations

µ-tomographic images are obtained for few soft materials with multi-structure, cylinder with holes of different diameter and biological soft tissue. 2D images are obtained in the transmission mode. 3D images are reconstructed with the use of the 2D slices for visualization of the internal structure. In addition, we used few simple geometrical approximations, for example, total geometrical efficiency, solid angle contribution and gradient. We obtained a series of images in the region 24-27 keV. 3D visualization of the materials is processed and analyzed the results. The present study is also focused on few geometrical considerations in order to design the collimators in front of the fluorescent source to improve the geometrical efficiency

X-ray scattering cross sections for molecules, plastics, tissues, and few biological materials

Compton and Rayleigh scattering cross sections for bone, bakelite, polycarbonate, nylon, lucite, polystyrene, polyethylene, water, glycogen, fat, calcium hydroxyapatite and protein are calculated for various monoenergetic Kα X-ray energies covering the angular region from 0 to 180° using non-relativistic, relativistic, relativistic modified and molecular form factors and the non-relativistic incoherent scattering function. The scattered radiation from these materials will be very useful to develop a semianalytic model to investigate the potential applications of X-ray scatter imaging. The scatter model can be used as a tool for designing and optimizing X-ray imaging system. However, one particular area of interest is in Monte Carlo simulation of photon transport in applications to medical physics and radiography

Cork embedded internal features and contrast mechanisms with DEI using 18, 20, 30, 36, and 40 kev synchrotron x-rays

Images of the cork used for wine and other bottles are visualized with the use of diffraction-enhanced imaging (DEI) technique. Present experimental studies allowed us to identify the cracks, holes, porosity, and importance of soft-matter (soft-material) and associated biology by visualization of the embedded internal complex features of the biological material such as cork and its microstructure. Highlighted the contrast mechanisms above and below the K-absorption edge of iodine and studied the attenuation through a combination of weakly and strongly attenuating materials. Copyright © 2010 Crown copyright

X-ray transmission and Compton CT investigation of some gastropods from Sassari, Sardinia, in Italy

Transmission and Compton tomographic images of a few gastropods (type: Helix aspersa and Monzettee) were obtained using a tube source of x-rays. Transmission tomographic systems consist of an x-ray tube, image intensifier, and CCD camera. A Compton tomographic imaging system consists of an x-ray tube, translation-rotation arrangement for sample, collimated NaI (Tl) detector, and the associated electronics for the image acquisition. Transmission images are obtained at 27 kV and 4 mA and Compton images at 40 kV and 4 mA. Images obtained in these two methods are compared and analyzed

Velada en honor de don Ricardo Carrasquilla

Relatoría de la velada en honor a don Ricardo Carrasquilla

Geometrical efficiency, solid angle contribution and gradient for a triaxial system equipped with a fluorescent source and x-ray tube: an analysis to enhance the Compton scattered photons

The total geometrical efficiency, solid angle contribution and gradient were estimated theoretically for a sample placed in a triaxial system equipped with a fluorescent source and x-ray tube. The contribution of all of the above parameters were assessed at two different secondary target angles with distance. These values are useful for the triaxial system to measure the basic interaction cross-sections excited by keV photons, to enhance the Compton scattered photons, estimation of monochromacy, solid angle correction and geometrical efficiency. Initially, the secondary target and sample are located at an angle of 45° and detected the scattered radiation from the sample to enhance the Compton scattered photons. By placing the sample at 90° in a triaxial system, the contribution of background is estimated. Comparing the data obtained in the two modes, the Compton photons are enhanced. An analysis of the above parameters and their importance for various potential applications are thoroughly discussed

Use of synchrotron-based diffraction-enhanced imaging for visualization of soft tissues in invertebrates

Images of terrestrial and marine invertebrates (snails and bivalves) have been obtained by using an X-ray phase-contrast imaging technique, namely, synchrotron-based diffraction-enhanced imaging. Synchrotron X-rays of 20, 30 and 40 key were used, which penetrate deep enough into animal soft tissues. The phase of X-ray photons shifts slightly as they traverse an object, such as animal soft tissue, and interact with its atoms. Biological features, such as shell morphology and animal physiology, have been visualized. The contrast of the images obtained at 40 key is the best. This optimum energy provided a clear view of the internal structural organization of the soft tissue with better contrast. The contrast is higher at edges of internal soft-tissue structures. The image improvements achieved with the diffraction-enhanced imaging technique are due to extinction, i.e., elimination of ultra-small-angle scattering. They enabled us to identify a few embedded internal shell features, such as the origin of the apex, which is the firmly attached region of the soft tissue connecting the umbilicus to the external morphology. Diffraction-enhanced imaging can provide high-quality images of soft tissues valuable for biology. (C) 2010 Elsevier Ltd. All rights reserved