scholarly journals The Lowest Radiation Dose Having Molecular Changes in the Living Body

Dose-Response ◽  
2018 ◽  
Vol 16 (2) ◽  
pp. 155932581877732 ◽  
Author(s):  
Noriko Shimura ◽  
Shuji Kojima
Keyword(s):  
Radiation Dose ◽  
Metal Ion ◽  
Fast Neutrons ◽  
Radiation Doses ◽  
Adaptive Responses ◽  
Dna Double Strand Breaks ◽  
High Background ◽  
Molecular Changes ◽  
X Ray ◽  
Living Body

We herein attempted to identify the lowest radiation dose causing molecular changes in the living body. We investigated the effects of radiation in human cells, animals, and humans. DNA double-strand breaks (DSBs) formed in cells at γ- or X-ray irradiation doses between 1 mGy and 0.5 Gy; however, the extent of DSB formation differed depending on the cell species. The formation of micronuclei (MNs) and nucleoplasmic bridges (NPBs) was noted at radiation doses between 0.1 and 0.2 Gy. Stress-responsive genes were upregulated by lower radiation doses than those that induced DNA DSBs or MN and NPBs. These γ- or X-ray radiation doses ranged between approximately 10 and 50 mGy. In animals, chromosomal aberrations were detected between 50 mGy and 0.1 Gy of low linear energy transfer radiation, 0.1 Gy of metal ion beams, and 9 mGy of fast neutrons. In humans, DNA damage has been observed in children who underwent computed tomography scans with an estimated blood radiation dose as low as 0.15 mGy shortly after examination. The frequencies of chromosomal translocations were lower in residents of high background areas than in those of control areas. In humans, systemic adaptive responses may have been prominently expressed at these radiation doses.

Estimation of Radiation Doses in X-Ray Visualization of Biological Objects

2014 ◽  
Vol 880 ◽  
pp. 53-56 ◽  
Author(s):  
Sergei Stuchebrov ◽  
Andrey Batranin ◽  
Dan Verigin ◽  
Yelena Lukyanenko ◽  
Maria Siniagina ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Biological Object ◽  
Gas Discharge ◽  
Radiation Doses ◽  
Semiconductor Detectors ◽  
Interior Structure ◽  
Dose Calculations ◽  
Object Control ◽  
X Ray ◽  
Biological Objects

Two setups for X-ray visualization of objects interior structure were designed and assembled in TPU. These radiographic systems are based on linear gas-discharge and GaAs semiconductor detectors. During investigation of biological object control of radiation doses has a high priority. In this report radiation dose calculations in X-ray visualization are presented. These calculation also includes dose calculations of sinograms which are used for reconstruction of tomography slices.

Estimating Radiation Dose to Major Organs in Dental X-Ray Examinations: A Phantom Study

2020 ◽  
Author(s):  
Yong Li ◽  
Bingsheng Huang ◽  
Jun Cao ◽  
Tianqi Fang ◽  
Guoqing Liu ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Reference Level ◽  
Radiation Doses ◽  
Diagnostic Reference Level ◽  
Effective Radiation Dose ◽  
Organ Doses ◽  
X Ray ◽  
Absorbed Doses ◽  
Males And Females ◽  
Effective Radiation

Abstract The radiation doses absorbed by major organs of males and females were studied from three types of dental X-ray devices. The absorbed doses from cone-beam computed tomography (CBCT), panoramic and intraoral X-ray machines were in the range of 0.23–1314.85 μGy, and were observed to be high in organs and tissues located in or adjacent to the irradiated area, there were discrepancies in organ doses between male and female. Thyroid, salivary gland, eye lens and brain were the organs that received higher absorbed doses. The organ absorbed doses were considerably lower than the diagnostic reference level for dental radiography in China. The calculated effective radiation doses for males and females were 56.63, 8.15, 2.56 μSv and 55.18, 8.99, 2.39 μSv, respectively, when using CBCT, the panoramic X-ray machine and intraoral X-ray machine. The effective radiation dose caused by CBCT was much higher than those of panoramic and intraoral X-ray machines.

Radiographers’ knowledge regarding patients’ ionizing radiation doses during common radiological procedures in Saudi Arabia

2020 ◽  
Vol 55 (1) ◽  
pp. 55-60 ◽  
Author(s):  
F.M. Aldhafeeri
Keyword(s):  
Saudi Arabia ◽  
Radiation Dose ◽  
Radiation Doses ◽  
Multiple Choice Questions ◽  
Effective Radiation Dose ◽  
X Ray ◽  
Level Of Knowledge ◽  
Survey Responses ◽  
Radiological Procedures ◽  
Radiological Examinations

To evaluate the level of knowledge and awareness regarding radiation doses from common radiological examinations among 100 radiographers working in different hospitals across Saudi Arabia, a questionnaire comprising 21 multiple-choice questions was electronically distributed to 180 radiographers working in medical imaging departments in various hospitals in Saudi Arabia. Participants were instructed to estimate the radiation dose administrated to patients during common radiological procedures. I received 100 survey responses. Only 13% (n = 13) of the participants correctly identified the effective radiation dose from 1-view chest and abdominal X-ray, whereas 7% (n = 7) correctly identified the dose from 2-view chest X-ray. Approximately half of the participants underestimated the patient dose from head and abdominal computed tomography and 2-view unilateral mammogram. Moreover, 17–26% correctly estimated the patient’s risk of fatal cancer from common radiological procedures. These results revealed a remarkably low level of knowledge among radiographers regarding radiation dose and risks. The vast majority of radiographers underestimated radiation doses and associated risks from common radiological examinations. The number of bachelor’s programs in Saudi Arabia has been extremely limited in the past decade. Most radiographers hold a diploma degree, which does not include any courses on radiation dose or protection. Continuous professional development in radiation safety is required to practice radiography.

The radiation doses and radiation protection on the endoscopic retrograde cholangiopancreatography procedures

2021 ◽  
pp. 20210399
Author(s):  
Mamoru Takenaka ◽  
Makoto Hosono ◽  
Shiro Hayashi ◽  
Tsutomu Nishida ◽  
Masatoshi Kudo
Keyword(s):  
Radiation Dose ◽  
Radiation Exposure ◽  
Endoscopic Retrograde Cholangiopancreatography ◽  
Radiation Doses ◽  
Average Dose ◽  
Endoscopic Retrograde ◽  
X Ray ◽  
Endoscopic Procedures ◽  
Dose Area Product ◽  
Therapeutic Ercp

Although many interventions involving radiation exposure have been replaced to endoscopic procedure in the gastrointestinal and hepatobiliary fields, there remains no alternative for enteroscopy and endoscopic retrograde cholangiopancreatography (ERCP), which requires the use of radiation. In this review, we discuss the radiation doses and protective measures of endoscopic procedures, especially for ERCP. For the patient radiation dose, the average dose area product for diagnostic ERCP was 14–26 Gy.cm², while it increased to as high as 67–89 Gy.cm² for therapeutic ERCP. The corresponding entrance skin doses for diagnostic and therapeutic ERCP were 90 and 250 mGy, respectively. The mean effective doses were 3– 6 mSv for diagnostic ERCP and 12–20 mSv for therapeutic ERCP. For the occupational radiation dose, the typical doses were 94 μGy and 75 μGy for the eye and neck, respectively. However, with an over-couch-type X-ray unit, the eye and neck doses reached as high as 550 and 450 μGy, with maximal doses of up to 2.8 and 2.4 mGy/procedure, respectively. A protective lead shield was effective for an over couch X-ray tube unit. It lowered scattered radiation by up to 89.1% in a phantom study. In actual measurements, the radiation exposure of the endoscopist closest to the unit was reduced to approximately 12%. In conclusion, there is a clear need for raising awareness among medical personnel involved endoscopic procedures to minimise radiation risks to both the patients and staff.

scholarly journals Bismuth Pelvic X-Ray Shielding Reduces Radiation Dose Exposure in Pediatric Radiography

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Bow Wang ◽  
Chien-Yi Ting ◽  
Cheng-Shih Lai ◽  
Yi-Shan Tsai
Keyword(s):  
Radiation Dose ◽  
Background Radiation ◽  
Radiation Doses ◽  
X Ray ◽  
Radiation Dose Exposure ◽  
Bismuth Shielding ◽  
Pediatric Radiography ◽  
Pelvic Radiography ◽  
Radiosensitive Organs ◽  
Pediatric Orthopedic

Background. Radiation using conventional X-ray is associated with exposure of radiosensitive organs and typically requires the use of protection. This study is aimed at evaluating the use of bismuth shielding for radiation protection in pediatric pelvic radiography. The effects of the anteroposterior and lateral bismuth shielding were verified by direct measurements at the anatomical position of the gonads. Methods. Radiation doses were measured using optically stimulated luminescence dosimeters (OSLD) and CIRS ATOM Dosimetry Verification Phantoms. Gonad radiographs were acquired using different shields of varying material (lead, bismuth) and thickness and were compared with radiographs obtained without shielding to examine the effects on image quality and optimal reduction of radiation dose. All images were evaluated separately by three pediatric orthopedic practitioners. Results. Results showed that conventional lead gonadal shielding reduces radiation doses by 67.45%, whereas dose reduction using one layer of bismuth shielding is 76.38%. The use of two layers of bismuth shielding reduces the dose by 84.01%. Using three and four layers of bismuth shielding reduces dose by 97.33% and 99.34%, respectively. Progressively lower radiation doses can be achieved by increasing the number of bismuth layers. Images obtained using both one and two layers of bismuth shielding provided adequate diagnostic information, but those obtained using three or four layers of bismuth shielding were inadequate for diagnosis. Conclusions. Bismuth shielding reduces radiation dose exposure providing appropriate protection for children undergoing pelvic radiography. The bismuth shielding material is lighter than lead, making pediatric patients more comfortable and less apt to move, thereby avoiding repeat radiography.

scholarly journals Occupational radiation exposure of orthopedists at different locations during pedicle screw insertion: An anthropomorphic phantom study

2021 ◽  
Vol 29 ◽  
pp. 211-219
Author(s):  
Hsien-Wen Chiang ◽  
Re-Wen Wu ◽  
Tsung-Cheng Yin ◽  
Jung-Hui Li ◽  
Yue-Sheng Wang ◽  
...  
Keyword(s):  
Radiation Dose ◽  
Pedicle Screw ◽  
Scattered Radiation ◽  
Thoracolumbar Spine ◽  
Radiation Doses ◽  
Operating Table ◽  
Flat Panel ◽  
X Ray ◽  
Orthopedic Surgeons ◽  
Occupational Radiation

BACKGROUND: The purpose of this work was to evaluate orthopedic surgeons’ exposure to occupational radiation doses from scattering using a mobile flat panel C-arm X-ray machine at different standing positions during an intraoperative pedicle screw implantation. OBJECTIVE: Evaluate the radiation dose received by medical staff, by applying flat X-ray machine in surgical room during an intraoperative pedicle screw implantation. METHODS: A mobile flat-panel C-arm X-ray machine at a dedicated orthopedic operating room was used to image an anthropomorphic female phantom which was set in a prone position on the operating table. The X-ray was projected horizontally, and 1 minute continuous fluoroscopy was used for lumbar spine and thoracolumbar spine during pedicle screw implantation. Scattering radiation doses to orthopedic surgeons were measured at different standing positions and body heights (50, 100, 150 cm above the ground) with and without limited collimations. RESULTS: The dose area product (DAP) in this experiment is normalized as 343 μGy⋅m2. In the four areas, the lowest scattered radiation measured by DF is 11.2 vs. 0.7 μSv, outside and inside the lead suit, respectively, with or without restricted field, 150 cm above the ground, and the lowest scattered radiation dose inside the lead suit. It is 1.3 vs. 0.5 μSv. Comparing the highest dose of the TF at with the lowest dose of the DF, the average result is 73.7 vs. 11.1 μSv, P< 0.05. CONCLUSIONS: Using a mobile flat-panel C-arm X-ray machine during a pedicle screw implantation, the minimum scattering radiation to surgeons was found to be at the terminal DF area based on the analysis of the scattering doses orthopedic surgeons were exposed to.

The Employment of 197Hg EDTA in Kidney Scanning

1965 ◽  
Vol 05 (01) ◽  
pp. 56-67
Author(s):  
I. Pál ◽  
J. Földes ◽  
I. Krasznai
Keyword(s):  
Radiation Dose ◽  
Renal Cortex ◽  
Radiation Doses ◽  
Intravenous Pyelography ◽  
Edta Complex

SummaryThe authors investigated the use of 197Hg EDTA complex for kidney scanning. They describe the physical, biological and toxicological properties of the compound; its distribution within the organism, its excretion with urine and faeces and its uptake by the kidneys. The authors have established that the renal cortex selectively secretes the material which makes it suitable for kidney scanning. Some scintigrams of both normal and pathologic kidneys are presented.Finally a detailed discussion of the dosimetry is included. The radiation doses due to 197Hg EDTA are compared with those due to 203Hg-neohydrin and to intravenous pyelography. This comparison shows clearly that the use of 197Hg EDTA considerably decreases the radiation dose to the patient.

Radiation Minimisation and Outcome Maximisation in Cardiac Computed Tomograpy

2010 ◽  
Vol 6 (1) ◽  
pp. 15
Author(s):  
James P Earls ◽  
Jonathon A Leipsic ◽  
◽  
Keyword(s):  
Radiation Dose ◽  
Dose Reduction ◽  
New Technologies ◽  
Cardiac Computed Tomography ◽  
Substantial Reduction ◽  
Radiation Doses ◽  
Tube Current ◽  
Prospective Triggering ◽  
Effective Radiation ◽  
Selection Of

Recent reports have raised general awareness that cardiac computed tomography (CT) has the potential for relatively high effective radiation doses. While the actual amount of risk this poses to the patient is controversial, the increasing concern has led to a great deal of research on new CT techniques capable of imaging the heart at substantially lower radiation doses than was available only a few years ago. Methods of dose reduction include optimised selection of user-defined parameters, such as tube current and voltage, as well as use of new technologies, such as prospective triggering and iterative reconstruction. These techniques have each been shown to lead to substantial reduction in radiation dose without loss of diagnostic accuracy. This article will review the most frequently used and widely available methods for radiation dose reduction in cardiac CT and give practical advice on their use and limitations.

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