scholarly journals Influence of extremely low energy radiation on artificial tissue: Effects on image quality and superficial dose

2008 ◽  
Vol 22 (5) ◽  
pp. 419-428 ◽  
Author(s):  
M.-Ali H. Al-Akhras ◽  
K. Aljarrah ◽  
A. Al-Omari ◽  
H. M. Al-Khateeb ◽  
B. A. Albiss ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Attenuation Coefficient ◽  
Soft Tissues ◽  
Biological Tissues ◽  
Low Energy ◽  
Linear Attenuation Coefficient ◽  
Polystyrene Microspheres ◽  
X Ray ◽  
Tissue Phantoms ◽  
Good Agreement

The design and slicing technique of artificial soft tissue are presented. Artificial soft tissue has optical penetration properties similar to biological tissues. The soft tissues are made of agar dissolved in water as a transparent tissue (control) incorporated with scatter materials such as polystyrene microspheres and absorbers such as artificial dairy substitute, coffee mate (Carnation Co.). The radiation's interaction with 20 and 40 keV X-ray, and visible light (400–800 nm) with different types of tissue phantoms has been investigated. The half value layer (HVL), attenuation coefficient, energy density and penetration depth through the artificial tissues has been calculated. X-ray radiation depth show significant reduction in soft tissue incorporated with polystyrene microspheres. At extremely low energy (E), the half value layer decreases with increasing the energy, while the attenuation coefficient increase. The calculated values of the half value layers are in very good agreement with experimental results. The calculated values of effective linear attenuation coefficient, are found to be µeff(0.22–0.42). Significant reduction in superficial dose with clear image is found with 10 mm soft tissue filter used. These results suggests: possible enhancement in diagnostic imaging and reduction in excess dose to patients; artificial soft tissue can be used as filter substitute.

scholarly journals Investigation of polymer-based BaO and rGO nanocomposites for application in low energy X ray attenuation

2019 ◽  
Vol 7 (2B) ◽  
Author(s):  
LILIANE Aparecida SILVA ◽  
Adriana Batistab ◽  
Jefferson Nascimentoc ◽  
Clascidia Furtadoc ◽  
Luiz Faria
Keyword(s):  
Thin Films ◽  
Attenuation Coefficient ◽  
Vinylidene Fluoride ◽  
Polymeric Materials ◽  
Radiation Shielding ◽  
Low Energy ◽  
Linear Attenuation Coefficient ◽  
Graphene Oxides ◽  
X Ray ◽  
Multilayered Sample

Polymeric materials can serve as a matrix for the dispersion of nanomaterials with good attenuation features, resulting in lightweight, conformable, flexible, lead-free and easy-to-process materials. Thus, some well-known radiation shielding materials could be used in low proportion as a filler, for the formation of new materials. On the other hand, nanostructured carbon materials, such as graphene oxide (GO) have been reported recently to show enhanced attenuation properties. For the present work, poly(vinylidene fluoride) [PVDF] homopolymers and its fluorinated copolymers were filled with metallic oxides and nanosized reduced graphene oxides (rGO) in order to produce nanocomposites with increased low energy X ray attenuation efficiency. We objective is to investigate the X ray shielding features of multilayered PVDF/rGO and P(VDF-TrFE)/BaO composites. PVDF/rGO overlapped with P(VDF-TrFE)/BaO thin films were sandwiched between two layers of kapton films of different thickness. The linear attenuation coefficients were measured for monochromatic X ray photons with energy of 8.1 keV. The samples were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Ultraviolet–visible (UV-vis) and Fourier-Transform Infrared (FTIR) Spectroscopy. The linear attenuation coefficient of the multilayered sample was evaluated and compared with the linear attenuation of the individual constituents. It was observed an increase in the attenuation coefficient of the overlapping samples. It is demonstrated that thin films of rGO nanocomposite with thickness of only 0.32 mm can attenuate up to 50% of X ray beams with energy of 8.1 keV, justifying further investigation of these nanocomposites as X ray or gamma radiation attenuators

scholarly journals X-ray Shielding, Mechanical, Physical, and Water Absorption Properties of Wood/PVC Composites Containing Bismuth Oxide

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2212
Author(s):  
Worawat Poltabtim ◽  
Ekachai Wimolmala ◽  
Teerasak Markpin ◽  
Narongrit Sombatsompop ◽  
Vichai Rosarpitak ◽  
...  
Keyword(s):  
Impact Strength ◽  
Water Absorption ◽  
Attenuation Coefficient ◽  
Bismuth Oxide ◽  
Morphological Properties ◽  
Linear Attenuation Coefficient ◽  
X Rays ◽  
Equivalent Thickness ◽  
X Ray ◽  
The Impact

The potential utilization of wood/polyvinyl chloride (WPVC) composites containing an X-ray protective filler, namely bismuth oxide (Bi2O3) particles, was investigated as novel, safe, and environmentally friendly X-ray shielding materials. The wood and Bi2O3 contents used in this work varied from 20 to 40 parts per hundred parts of PVC by weight (pph) and from 0 to 25, 50, 75, and 100 pph, respectively. The study considered X-ray shielding, mechanical, density, water absorption, and morphological properties. The results showed that the overall X-ray shielding parameters, namely the linear attenuation coefficient (µ), mass attenuation coefficient (µm), and lead equivalent thickness (Pbeq), of the WPVC composites increased with increasing Bi2O3 contents but slightly decreased at higher wood contents (40 pph). Furthermore, comparative Pbeq values between the wood/PVC composites and similar commercial X-ray shielding boards indicated that the recommended Bi2O3 contents for the 20 pph (40 ph) wood/PVC composites were 35, 85, and 40 pph (40, 100, and 45 pph) for the attenuation of 60, 100, and 150-kV X-rays, respectively. In addition, the increased Bi2O3 contents in the WPVC composites enhanced the Izod impact strength, hardness (Shore D), and density, but reduced water absorption. On the other hand, the increased wood contents increased the impact strength, hardness (Shore D), and water absorption but lowered the density of the composites. The overall results suggested that the developed WPVC composites had great potential to be used as effective X-ray shielding materials with Bi2O3 acting as a suitable X-ray protective filler.

scholarly journals Determining paediatric patient thickness from a single digital radiograph—a proof of principle

2018 ◽  
Vol 91 (1087) ◽  
pp. 20180139 ◽  
Author(s):  
Mark Worrall ◽  
Sarah Vinnicombe ◽  
David G Sutton
Keyword(s):  
Paediatric Patient ◽  
Attenuation Coefficient ◽  
A Priori ◽  
A Priori Knowledge ◽  
Linear Attenuation Coefficient ◽  
Clinical Tool ◽  
X Ray ◽  
Pixel Value ◽  
Solid Water ◽  
Proof Of Principle

Objective: This work presents a proof of principle for a method of estimating the thickness of an attenuator from a single radiograph using the image, the exposure factors with which it was acquired and a priori knowledge of the characteristics of the X-ray unit and detector used for the exposure. It is intended this could be developed into a clinical tool to assist with paediatric patient dose audit, for which a measurement of patient size is required. Methods: The proof of principle used measured pixel value and effective linear attenuation coefficient to estimate the thickness of a Solid Water attenuator. The kerma at the detector was estimated using a measurement of pixel value on the image and measured detector calibrations. The initial kerma was estimated using a lookup table of measured output values. The effective linear attenuation coefficient was measured for Solid Water at varying kVp. 11 test images of known and varying thicknesses of Solid Water were acquired at 60, 70 and 81 kVp. Estimates of attenuator thickness were made using the model and the results compared to the known thickness. Results: Estimates of attenuator thickness made using the model differed from the known thickness by 3.8 mm (3.2%) on average, with a range of 0.5–10.8 mm (0.5–9%). Conclusion: A proof of principle is presented for a method of estimating the thickness of an attenuator using a single radiograph of the attenuator. The method has been shown to be accurate using a Solid Water attenuator, with a maximum difference between estimated and known attenuator thickness of 10.8 mm (9%). The method shows promise as a clinical tool for estimating abdominal paediatric patient thickness for paediatric patient dose audit, and is only contingent on the type of data routinely collected by Medical Physics departments. Advances in knowledge: A computational model has been created that is capable of accurately estimating the thickness of a uniform attenuator using only the radiographic image, the exposure factors with which it was acquired and a priori knowledge of the characteristics of the X-ray unit and detector used for the exposure.

Conversion Factors between Energy Imparted to the Patient and Air Collision Kerma Integrated over Beam Area in Pediatric Radiology

1993 ◽  
Vol 34 (1) ◽  
pp. 92-98 ◽  
Author(s):  
J. Persliden ◽  
M. Sandborg
Keyword(s):  
Monte Carlo ◽  
Soft Tissue ◽  
Conversion Factor ◽  
Field Size ◽  
Conversion Factors ◽  
X Ray ◽  
Monte Carlo Calculations ◽  
Tissue Phantoms ◽  
Tube Potential ◽  
Pediatric Radiography

Conversion factors between the energy imparted to the patient in pediatric radiography and air collision kerma integrated over beam area are presented. The values have been derived from Monte Carlo calculations in soft tissue phantoms and extend results published earlier to cover children from early infancy to the age of 15 years. Variations related to phantom size as well as to focus-phantom distance, radiation field size, orientation of view (a.p., lateral), tube potential, and beam filtration are given. We show that the conversion factor increases with increasing half-value layer of the X-ray beam and the anterioposterior width of the simulated child. Increasing the focus-phantom distance increases the conversion factor, while increasing the field size decreases the factors due to more scattered radiation escaping laterally from the phantom.

Magnetic Resonance Imaging in Retropharyngeal Tendinitis

Cephalalgia ◽  
1994 ◽  
Vol 14 (4) ◽  
pp. 266-269 ◽  
Author(s):  
K Ekbom ◽  
J Tothall ◽  
K Annell ◽  
J Träff
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cervical Spine ◽  
Magnetic Resonance ◽  
Soft Tissue ◽  
Signal Intensity ◽  
Soft Tissues ◽  
Resonance Imaging ◽  
X Ray ◽  
Soft Tissue Swelling ◽  
Retropharyngeal Tendinitis

Seven consecutive patients with acute retropharyngeal tendinitis underwent plain X-ray and magnetic resonance imaging (MRI) of the cervical spine. All seven had marked soft tissue swelling anterior to C1 and C2 on plain X-ray, and soft tissue calcification at this level was present in five of them. On MRI, there was markedly increased signal intensity on T2-weighted images in the acute phase and intermediate signal intensity on T1-weighted images, anterior to the level of C1 and C2, often extending as far down as C6. These changes correlated well with the soft tissue swelling seen on conventional X-ray of the cervical spine. The maximum mid-sagittal thickness of the soft tissues was significantly greater in the tendinitis patients ( p < 0.001) than in 12 control subjects free of symptoms from the pharynx or the cervical spine. Treatment with non-steroidal anti-inflammatory drugs rapidly alleviated symptoms, and at follow-up MRI showed regression or complete restitution of the changes. In conclusion, MRI can visualize the edematous changes in the longus colli muscle and adds useful diagnostic information in suspected cases of acute retropharyngeal tendinitis.

scholarly journals Linear Attenuation as an Indicator for Safe Water

2019 ◽  
pp. 235-247
Author(s):  
M. U. Mgbukwu ◽  
L. D. Christopher ◽  
A. J. Iseh
Keyword(s):  
Attenuation Coefficient ◽  
Water Samples ◽  
Total Hardness ◽  
Linear Attenuation Coefficient ◽  
X Ray ◽  
Safe Water ◽  
A Value ◽  
Quality Of Water ◽  
Plateau State

This study analyses the linear attenuation coefficient as an indicator for safe water, the study was carried out using various water samples from borehole, well and pond in two Local Government Areas namely, Jos North and Jos East areas of Plateau State, Nigeria. The samples were collected in a Perspex of volume 7cmX7cmX7cm and filled to a height of 3cm. Energy of 70kVp of X-ray was passed through the samples with an X-ray detector under the Perspex of water to get the different final X-ray doses. From the study the linear attenuation coefficient ranges from 0.2878cm-1-0.4270cm-1, 0.3074cm-1-0.4743cm-1, 0.3074cm-1-0.4743cm-1 for borehole, well and pond in that order. The study showed a strong correlation between the linear attenuation coefficient and turbidity, total hardness and density which follows a trend for different samples. The highest value of linear attenuation ranges from borehole, well, pond in that order. This study was able to get a value of linear attenuation coefficient for safe water which ranges from 0.40203cm-1-0.02414cm-1 which can be used to ascertain the quality of water.

scholarly journals Distinguishing Biology from Geology in Soft-Tissue Preservation

2014 ◽  
Vol 20 ◽  
pp. 275-288 ◽  
Author(s):  
John A. Cunningham ◽  
Philip C. J. Donoghue ◽  
Stefan Bengtson
Keyword(s):  
Soft Tissue ◽  
Laser Beam ◽  
Evolutionary History ◽  
Soft Tissues ◽  
Analytical Techniques ◽  
Tissue Preservation ◽  
Deep Time ◽  
X Ray ◽  
Soft Tissue Preservation

Knowledge of evolutionary history is based extensively on relatively rare fossils that preserve soft tissues. These fossils record a much greater proportion of anatomy than would be known solely from mineralized remains and provide key data for testing evolutionary hypotheses in deep time. Ironically, however, exceptionally preserved fossils are often among the most contentious because they are difficult to interpret. This is because their morphology has invariably been affected by the processes of decay and diagenesis, meaning that it is often difficult to distinguish preserved biology from artifacts introduced by these processes. Here we describe how a range of analytical techniques can be used to tease apart mineralization that preserves biological structures from unrelated geological mineralization phases. This approach involves using a series of X-ray, ion, electron and laser beam techniques to characterize the texture and chemistry of the different phases so that they can be differentiated in material that is difficult to interpret. This approach is demonstrated using a case study of its application to the study of fossils from the Ediacaran Doushantuo Biota.

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