scholarly journals The effect of underlying bone on the beam angular correction in calculating the skin dose of the head in neuro-interventional imaging

Author(s):  
Sheng-Hsuan Sun ◽  
Stephen Rudin ◽  
Daniel R. Bednarek
Author(s):  
Suichu Luo ◽  
John R. Dunlap ◽  
Richard W. Williams ◽  
David C. Joy

In analytical electron microscopy, it is often important to know the local thickness of a sample. The conventional method used for measuring specimen thickness by EELS is:where t is the specimen thickness, λi is the total inelastic mean free path, IT is the total intensity in an EEL spectrum, and I0 is the zero loss peak intensity. This is rigorouslycorrect only if the electrons are collected over all scattering angles and all energy losses. However, in most experiments only a fraction of the scattered electrons are collected due to a limited collection semi-angle. To overcome this problem we present a method based on three-dimension Poisson statistics, which takes into account both the inelastic and elastic mixed angular correction.The three-dimension Poisson formula is given by:where I is the unscattered electron intensity; t is the sample thickness; λi and λe are the inelastic and elastic scattering mean free paths; Si (θ) and Se(θ) are normalized single inelastic and elastic angular scattering distributions respectively ; F(E) is the single scattering normalized energy loss distribution; D(E,θ) is the plural scattering distribution,


2020 ◽  
Vol 4 (2) ◽  
pp. 722-729
Author(s):  
Usman Sani ◽  
Bashir Gide Muhammad ◽  
Dimas Skam Joseph ◽  
D. Z. Joseph

Poor implementation of quality assurance programs in the radiation industry has been a major setback in our locality. Several studies revealed that occupational workers are exposed to many potential hazards of ionizing radiation during radio-diagnostic procedures, yet radiation workers are often not monitored. This study aims to evaluate the occupational exposure of the radiation workers in Federal Medical Centre Katsina, and to compare the exposure with recommended occupational radiation dose limits. The quarterly readings of 20 thermo-luminescent dosimeters (TLDs') used by the radiation workers from January to December, 2019 were collected from the facility's radiation monitoring archive, and subsequently assessed and analyzed. The results indicate that the average annual equivalent dose per occupational worker range from 0.74 to 1.20 mSv and 1.28 to 2.21 mSv for skin surface and deep skin dose, measured at 10 mm and 0.07 mm tissue depth respectively. The occupational dose was within the recommended national and international limits of 5 mSv per annum or an average of 20 mSv in 5 years. Therefore, there was no significant radiation exposure to all the occupational workers in the study area. Though, the occupational radiation dose is within recommended limit, this does not eliminate stochastic effect of radiation. The study recommended that the occupational workers should adhere and strictly comply with the principles of radiation protection which includes distance, short exposure time, shielding and proper monitoring of dose limits. Furthermore, continuous training of the radiation workers is advised.


2021 ◽  
Author(s):  
Jonas Andersson ◽  
Daniel R. Bednarek ◽  
Wesley Bolch ◽  
Thomas Boltz ◽  
Hilde Bosmans ◽  
...  
Keyword(s):  

2015 ◽  
Vol 31 ◽  
pp. e47
Author(s):  
J. Greffier ◽  
C. Van Ngog Ty ◽  
G. Bonniaud ◽  
B. Ledermann ◽  
S. Ovtchinnikoff ◽  
...  

1997 ◽  
Vol 72 (6) ◽  
pp. 835-841 ◽  
Author(s):  
D. C. Taylor ◽  
E. M. A. Hussein ◽  
P. S. Yuen

2005 ◽  
Vol 117 (1-3) ◽  
pp. 185-189 ◽  
Author(s):  
J. Van Dam ◽  
H. Bosmans ◽  
G. Marchal ◽  
A. Wambersie
Keyword(s):  

2011 ◽  
Vol 38 (5) ◽  
pp. 2419-2423 ◽  
Author(s):  
Ivaylo B. Mihaylov ◽  
Karl Bzdusek ◽  
Michael Kaus
Keyword(s):  

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