scholarly journals Effect of X-ray irradiation on ancient DNA in sub-fossil bones – Guidelines for safe X-ray imaging

2016 ◽  
Author(s):  
Alexander Immel ◽  
Adeline Le Cabec ◽  
Marion Bonazzi ◽  
Alexander Herbig ◽  
Heiko Temming ◽  
...  
Keyword(s):  
Ancient Dna ◽  
Clear Correlation ◽  
X Ray ◽  
X Ray Imaging ◽  
Fossil Bones ◽  
X Ray Computed ◽  
Synchrotron Imaging ◽  
Micro Tomography ◽  
Living Organisms ◽  
Dose Levels

AbstractSub-fossilised remains may still contain highly degraded ancient DNA (aDNA) useful for palaeogenetic investigations. Whether X-ray computed [micro-] tomography ([μ]CT) imaging of these fossils may further damage aDNA remains debated. Although the effect of X-ray on DNA in living organisms is well documented, its impact on aDNA molecules is unexplored.Here we investigate the effects of synchrotron X-ray irradiation on aDNA from Pleistocene bones. A clear correlation appears between decreasing aDNA quantities and accumulating X-ray dose-levels above 2000 Gray (Gy). We further find that strong X-ray irradiation reduces the amount of nucleotide misincorporations at the aDNA molecule ends. No representative effect can be detected for doses below 200 Gy. Dosimetry shows that conventional μCT usually does not reach the risky dose level, while classical synchrotron imaging can degrade aDNA significantly. Optimised synchrotron protocols and simple rules introduced here are sufficient to ensure that fossils can be scanned without impairing future aDNA studies.

scholarly journals Optimization of the energy for Breast monochromatic absorption X-ray Computed Tomography

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Pasquale Delogu ◽  
Vittorio Di Trapani ◽  
Luca Brombal ◽  
Giovanni Mettivier ◽  
Angelo Taibi ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Imaging Techniques ◽  
Fixed Dose ◽  
X Rays ◽  
Reconstruction Algorithms ◽  
Contrast Resolution ◽  
X Ray ◽  
X Ray Imaging ◽  
X Ray Computed ◽  
Dose Levels

Abstract The limits of mammography have led to an increasing interest on possible alternatives such as the breast Computed Tomography (bCT). The common goal of all X-ray imaging techniques is to achieve the optimal contrast resolution, measured through the Contrast to Noise Ratio (CNR), while minimizing the radiological risks, quantified by the dose. Both dose and CNR depend on the energy and the intensity of the X-rays employed for the specific imaging technique. Some attempts to determine an optimal energy for bCT have suggested the range 22 keV–34 keV, some others instead suggested the range 50 keV–60 keV depending on the parameters considered in the study. Recent experimental works, based on the use of monochromatic radiation and breast specimens, show that energies around 32 keV give better image quality respect to setups based on higher energies. In this paper we report a systematic study aiming at defining the range of energies that maximizes the CNR at fixed dose in bCT. The study evaluates several compositions and diameters of the breast and includes various reconstruction algorithms as well as different dose levels. The results show that a good compromise between CNR and dose is obtained using energies around 28 keV.

scholarly journals Effect of X-ray irradiation on ancient DNA in sub-fossil bones – Guidelines for safe X-ray imaging

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Alexander Immel ◽  
Adeline Le Cabec ◽  
Marion Bonazzi ◽  
Alexander Herbig ◽  
Heiko Temming ◽  
...  
Keyword(s):  
Ancient Dna ◽  
X Ray ◽  
X Ray Imaging ◽  
Fossil Bones

scholarly journals Visualization Ability of Phase-Contrast Synchrotron-Based X-Ray Imaging Using an X-Ray Interferometer in Soft Tissue Tumors

2021 ◽  
Vol 20 ◽  
pp. 153303382110101
Author(s):  
Thet-Thet Lwin ◽  
Akio Yoneyama ◽  
Hiroko Maruyama ◽  
Tohoru Takeda
Keyword(s):  
Computed Tomography ◽  
Soft Tissue ◽  
Spatial Resolution ◽  
Phase Contrast ◽  
Soft Tissue Tumors ◽  
X Ray ◽  
3 Dimensional ◽  
Computed Tomography Images ◽  
X Ray Imaging ◽  
X Ray Computed

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.

A new species of anapid spider (Araneae: Araneoidea, Anapidae) in Eocene Baltic amber, imaged using phase contrast X-ray computed micro-tomography

Zootaxa ◽  
2011 ◽  
Vol 2742 (1) ◽  
pp. 60 ◽  
Author(s):  
DAVID PENNEY ◽  
ANDREW MCNEIL ◽  
DAVID I. GREEN ◽  
ROBERT BRADLEY ◽  
YURI M. MARUSIK ◽  
...  
Keyword(s):  
New Species ◽  
Phase Contrast ◽  
Baltic Amber ◽  
X Ray ◽  
The Family ◽  
X Ray Computed ◽  
Micro Tomography ◽  
The Baltic ◽  
A New Species ◽  
Eocene Amber

A new species of the extant spider family Anapidae is described from a fossil mature male in Eocene amber from the Baltic region and tentatively assigned to the genus Balticoroma Wunderlich, 2004. Phase contrast X-ray computed micro-tomography was used to reveal important features that were impossible to view using traditional microscopy. Balticoroma wheateri new species is easily diagnosed from all other anapids by having clypeal extensions that run parallel to the ectal surface of the chelicerae and in having the metatarsus of the first leg highly reduced and modified into what is presumably a y-shaped clasping structure. Although only a single extant anapid species occurs in northern Europe, the family was diverse in the Eocene. The discovery of yet another anapid species in Baltic amber supports the idea that Eocene European forests may have been a hotspot of evolution for this family of spiders.

Design, development and first experiments on the X-ray imaging beamline at Indus-2 synchrotron source RRCAT, India

2015 ◽  
Vol 22 (6) ◽  
pp. 1531-1539 ◽  
Author(s):  
A. K. Agrawal ◽  
B. Singh ◽  
Y. S. Kashyap ◽  
M. Shukla ◽  
P. S. Sarkar ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Imaging Techniques ◽  
Phase Contrast Imaging ◽  
Design Development ◽  
Contrast Imaging ◽  
Synchrotron Source ◽  
Full Field ◽  
X Ray ◽  
X Ray Imaging ◽  
Micro Tomography

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.

First experiments on the Australian Synchrotron Imaging and Medical beamline, including investigations of the effective source size in respect of X-ray imaging

2009 ◽  
Vol 17 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Andrew W. Stevenson ◽  
Sheridan C. Mayo ◽  
Daniel Häusermann ◽  
Anton Maksimenko ◽  
Richard F. Garrett ◽  
...  
Keyword(s):  
Source Size ◽  
X Ray ◽  
X Ray Imaging ◽  
Synchrotron Imaging ◽  
Effective Source

MTF, NPS and DQE characterization of an in-house developed X-ray imaging detector for synchrotron based micro-tomography

2014 ◽  
Vol 9 (06) ◽  
pp. C06001-C06001 ◽  
Author(s):  
K Desjardins ◽  
M Bordessoule ◽  
C Petrache ◽  
C Menneglier ◽  
D Dallé ◽  
...  
Keyword(s):  
X Ray ◽  
X Ray Imaging ◽  
Imaging Detector ◽  
Micro Tomography
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