scholarly journals A Review of Doses for Dental Imaging in 2010–2020 and Development of a Web Dose Calculator

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Hawon Lee ◽  
Andreu Badal
Keyword(s):  
Effective Dose ◽  
Dose Distribution ◽  
Web Application ◽  
Large Field ◽  
Imaging Procedures ◽  
Machine Model ◽  
Organ Doses ◽  
Distribution Maps ◽  
Dental Imaging ◽  
Effective Doses

Dental imaging is one of the most common types of diagnostic radiological procedures in modern medicine. We introduce a comprehensive table of organ doses received by patients in dental imaging procedures extracted from literature and a new web application to visualize the summarized dose information. We analyzed articles, published after 2010, from PubMed on organ and effective doses delivered by dental imaging procedures, including intraoral radiography, panoramic radiography, and cone-beam computed tomography (CBCT), and summarized doses by dosimetry method, machine model, patient age, and technical parameters. Mean effective doses delivered by intraoral, 1.32 (0.60–2.56) μSv, and panoramic, 17.93 (3.47–75.00) μSv, procedures were found to be about1% and 15% of that delivered by CBCT, 121.09 (17.10–392.20) μSv, respectively. In CBCT imaging, child phantoms received about 29% more effective dose than the adult phantoms received. The effective dose of a large field of view (FOV) (>150 cm2) was about 1.6 times greater than that of a small FOV (<50 cm2). The maximum CBCT effective dose with a large FOV for children, 392.2 μSv, was about 13% of theeffective dose that a person receives on average every year from natural radiation, 3110 μSv. Monte Carlo simulations of representative cases of the three dental imaging procedures were then conducted to estimate and visualize the dose distribution within the head. The user-friendly interactive web application (available at http://dentaldose.org) receives user input, such as the number of intraoral radiographs taken, and displays total organ and effective doses, dose distribution maps, and a comparison with other medical and natural sources of radiation. The web dose calculator provides a practical resource for patients interested in understanding the radiation doses delivered by dental imaging procedures.

RESULTS OF CZECH NATIONAL STUDY OF RADIATION EXPOSURE FROM RADIOTHERAPY OF NON-MALIGNANT DISEASES, IN PARTICULAR OF HEEL SPURS

2019 ◽  
Vol 186 (2-3) ◽  
pp. 386-390
Author(s):  
V Dufek ◽  
H Zackova ◽  
L Kotik ◽  
I Horakova
Keyword(s):  
Czech Republic ◽  
Clinical Practice ◽  
Radiation Exposure ◽  
Effective Dose ◽  
National Study ◽  
Malignant Diseases ◽  
Organ Doses ◽  
The Czech Republic ◽  
X Ray ◽  
Effective Doses

Abstract About 26 000 patients are treated per year with radiotherapy for non-malignant diseases in the Czech Republic. Approximately 75% of them are treated on X-ray therapy units and most of these patients undergo radiotherapy of heel spurs. The evaluation of radiation exposure of these patients was based on measured organ doses and on data from clinical practice. Collective effective doses for particular diagnoses were calculated in order to compare doses resulting from different diagnoses treated on X-ray therapy units. The collective effective dose from radiotherapy of heel spurs in the Czech Republic in 2013 was evaluated to 77 manSv. It represents 25.6% of the total collective effective dose for all diagnoses of radiotherapy for non-malignant diseases treated on X-ray therapy units.

scholarly journals Assessment of Organ and Effective Doses Received by Paediatric Patients Undergoing Computed Tomography Examinations in Three Hospitals in Brazzaville, Congo Republic: An Urgent Necessity for Regulatory Control

2021 ◽  
pp. 527-550
Author(s):  
J. Bazoma ◽  
G. B. Dallou ◽  
P. Ondo Meye ◽  
C. Bouka Biona ◽  
Saïdou ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Effective Dose ◽  
Absorbed Dose ◽  
Regulatory Control ◽  
Ct Scans ◽  
Radiological Protection ◽  
Age Group ◽  
Organ Doses ◽  
Paediatric Patients ◽  
Effective Doses

The present study aimed at estimating organ and effective doses from computed tomography (CT) scans of paediatric patients in three hospitals in Brazzaville, Congo Republic. A total of 136 data on paediatric patients, from 0.25 (3 months) to 15 years old, who underwent head, chest, abdomen – pelvis (AP) and chest – abdomen – pelvis (CAP) CT scans was considered. The approach followed in the present study to compute organ doses was to use pre-calculated volume CT dose index (CTDIvol) – and 100 milliampere-second (mAs) – normalized organ doses determined by Monte Carlo (MC) simulation. Effective dose were then derived using the international commission on radiological protection (ICRP) publications 60 and 103 formalism. For comparison purposes, effective dose were also computed using dose-length product (DLP) – to – effective dose conversion factors. A relatively high variation in organ and effective doses was observed in each age group due to the dependence of patient dose on the practice of technicians who perform the CT scan within the same facility or from one facility to another, patient size and lack of adequate training of technicians. In the particular case of head scan, the brain and the eye lens were delivered maximum absorbed doses of 991.81 mGy and 1176.51 mGy, respectively (age group 10-15 y). The maximum absorbed dose determined for the red bone marrow was 246.08 mGy (age group 1-5 y). This is of concern as leukaemia and brain tumours are the most common childhood cancers and as the ICRP recommended absorbed dose threshold for induction of cataract is largely exceeded. Effective doses derived from MC calculations and ICRP publications 60 and 103 tissues weighting factors showed a 0.40-17.61 % difference while the difference between effective doses derived by the use of k- factors and those obtained by MC calculations ranges from 0.06 to 224.87 %. The study has shown that urgent steps should be taken in order to significantly reduce doses to paediatric patients to levels observed in countries where dose reduction techniques are successfully applied.

ESTIMATION OF ORGAN DOSES AND EFFECTIVE DOSES BASED ON IN-PHANTOM DOSIMETRY FOR PAEDIATRIC DIAGNOSTIC CARDIAC CATHETERISATION

2019 ◽  
Vol 185 (2) ◽  
pp. 215-221
Author(s):  
Toshio Kawasaki ◽  
Masami Sakakubo ◽  
Kanako Ito ◽  
Ai Kitagawa
Keyword(s):  
Effective Dose ◽  
Cardiac Catheterization ◽  
Organ Doses ◽  
Conversion Factors ◽  
Dose Area Product ◽  
Diagnostic Cardiac Catheterization ◽  
Pediatric Dosimetry ◽  
Effective Doses ◽  
Area Product ◽  
Cardiac Catheterizations

Abstract The present study evaluated the organ doses, effective doses and conversion factors from the dose–area product to effective dose in pediatric diagnostic cardiac catheterization performed by in-phantom dosimetry and Monte Carlo simulation. The organ and effective doses in 5-y-olds during diagnostic cardiac catheterizations were evaluated using radiophotoluminescence glass dosemeters implanted into a pediatric anthropomorphic phantom and PCXMC software. The mean effective dose was 3.8 mSv (range: 1.8–7.5 mSv). The conversion factors from the dose–area product to effective dose were 0.9 and 1.6 mSv (Gy cm2)−1 for posteroanterior and lateral fluoroscopy, respectively, and 0.9 and 1.5 mSv (Gy cm2)−1 for posteroanterior and lateral cineangiography, respectively. Effective doses evaluated using the pediatric dosimetry system agreed with those obtained using PCXMC software within 12%. The dose data and conversion factors evaluated may guide the estimation of exposure doses in children undergoing diagnostic cardiac catheterization.

ESTIMATION OF ORGAN DOSES AND EFFECTIVE DOSES BASED ON IN-PHANTOM DOSIMETRY FOR INFANT DIAGNOSTIC CARDIAC CATHETERISATIONS WITH NOVEL X-RAY IMAGING TECHNOLOGY

2018 ◽  
Vol 183 (4) ◽  
pp. 529-534
Author(s):  
Toshio Kawasaki ◽  
Masami Sakakubo ◽  
Kanako Ito
Keyword(s):  
Effective Dose ◽  
Cardiac Catheterisation ◽  
Organ Doses ◽  
Conversion Factors ◽  
X Ray ◽  
Dose Area Product ◽  
X Ray Imaging ◽  
Effective Doses ◽  
The Mean ◽  
Area Product

Abstract The present study evaluated the organ and effective doses in infant diagnostic cardiac catheterisation performed using a modern x-ray imaging unit by in-phantom dosimetry. In addition, conversion factors from dose–area product (DAP) to effective dose were determined. The organ and effective doses in 1-year old during diagnostic cardiac catheterisations were measured using radiophotoluminescence glass dosemeters implanted into an infant anthropomorphic phantom. The mean effective doses, evaluated according to the International Commission on Radiologic Protection Publication 103, were 4.0 mSv (range: 1.5–8.7 mSv). The conversion factors from DAP to effective dose were 2 and 3.5 mSv (Gy cm2)−1 for posteroanterior and lateral fluoroscopy, respectively, and 1.8 and 3.3 mSv (Gy cm2)−1 for posteroanterior and lateral cineangiography, respectively. The dose data and conversion factors evaluated in the present study may be useful for estimating radiation exposure in infants during diagnostic cardiac catheterisation.

Effective dose estimation in cone-beam computed tomography for dental use by Monte-Carlo simulation optimizing calculation numbers using a step-and-shoot method

2021 ◽  
pp. 20210084
Author(s):  
Yoshihiro Ozaki ◽  
Hiroshi Watanabe ◽  
Tohru Kurabayashi
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Effective Dose ◽  
Heavy Ion ◽  
Cone Beam ◽  
Dose Estimation ◽  
Organ Doses ◽  
Shoot Method ◽  
Step And Shoot ◽  
Effective Doses

Objective: The objective of this study was to perform effective dose estimation in cone-beam CT for dental use (CBCT) using a Monte-Carlo simulation employing a step-and-shoot method as well as to determine the optimal number of steps. Methods: We simulated 3DX Accuitomo FPD8 as a CBCT model and estimated the effective doses of a large and a small field of view (FOV) examination against the virtual Rando phantom using a particle and heavy ion transport code system. We confirmed the results compared to those from a thermo-luminescence dosemeter (TLD) system in a real phantom and investigated how the reduced angle calculations could be accepted. Results: The effective doses of both FOVs estimated with each one degree were almost the same as those estimated from the TLD measurements. Considering the effective doses and the itemized organ doses, simulation with 5° and 10° is acceptable for the large and small FOV, respectively. We tried to compare an effective dose with a large FOV as well as with multiple small FOVs covering the corresponding area and found that the effective dose from six small FOVs was approximately 1.2 times higher than that of the large FOVs. Conclusion: We successfully performed a Monte-Carlo simulation using a step-and-shoot method and estimated the effective dose in CBCT. Our findings indicate that simulation with 5° or 10° is acceptable based on the FOV size, while a small multiple FOV scan is recommended from a radiation protection viewpoint.

scholarly journals Evaluation of Effective Dose with Two-dimensional and Three-dimensional Dental Imaging Devices

2015 ◽  
Vol 5 (2) ◽  
pp. 80-85 ◽  
Keyword(s):  
Computed Tomography ◽  
Effective Dose ◽  
Digital Imaging ◽  
3D Imaging ◽  
Three Dimensional ◽  
Dental Radiology ◽  
Two Dimensional ◽  
Dental Imaging ◽  
Thermoluminescent Dosimeters ◽  
Effective Doses

ABSTRACT Objectives Different types of X-ray equipment are used in dental radiology. Purpose of this study was to measure the absorbed doses of some critical organs and tissues in head and neck which were exposed by dental imaging devices that are used routinely in dental radiology. Materials and Methods Radiation exposures were performed by using a human equivalent head phantom and dose measurements were determined with thermoluminescent dosimeters (TLD). After exposure of the phantom with dental imaging devices, absorbed and effective doses of critical organs were determined. Results Digital imaging systems produced lower effective doses. Effective doses of cone beam computed tomography (CBCT) and multi-slice computed tomography (MSCT) devices were close to each other. Conclusion Effective doses of digital imaging devices were measured lower than conventional imaging devices. Effective doses of 3D imaging devices were measured higher than all the other imaging devices. However, effective doses of 3D imaging devices were considered in acceptable levels. How to cite this article Eren H, Gorgun S. Evaluation of Effective Dose with Two-dimensional and Three-dimensional Dental Imaging Devices. J Contemp Dent 2015;5(2):80-85.

Use of effective dose to assess x-ray protective clothing

2021 ◽  
Vol 41 (4) ◽  
pp. R140-R151
Author(s):  
Heinrich Eder ◽  
Helmut Schlattl
Keyword(s):  
Effective Dose ◽  
Protective Clothing ◽  
The Body ◽  
Special Role ◽  
X Rays ◽  
Dose Equivalent ◽  
Organ Doses ◽  
X Ray ◽  
Effective Doses ◽  
Subordinate Role

Abstract This review article provides an overview on the results of studies conducted by the authors to improve the current personal protection concept in the clinical application of x-rays. With the aid of personal dose equivalent measurements during radiologically guided clinical interventions, laboratory tests using the Alderson-Rando phantom as well as Monte Carlo simulations various x-ray application scenarios were investigated. The organ doses and the effective doses of staff persons standing near the patient were determined. The 3D-attenuation properties of protective clothing under the scattered radiation emitted by the patient play a special role here. With regard to the minimisation of the quantity ‘effective dose’ the protection of the lower body from the gonads to the chest is of particular importance, since 80% of the effective dose is contributed by this region of the body. In contrast, protection of the back plays a subordinate role. Protective aprons optimised in terms of effective dose can be significantly lighter than conventional aprons, providing equal protection. The assessment of the attenuation properties of protective clothing should be based on the risk-related dose quantity, effective dose, rather than lead equivalent. In the future, the evaluation of radiation protective clothing could be based on the calculation of the effective dose assuming standardised irradiation conditions.

Effective dose and risks from medical x-ray procedures

2012 ◽  
Vol 41 (3-4) ◽  
pp. 129-141 ◽  
Author(s):  
M.I. Balonov ◽  
P.C. Shrimpton
Keyword(s):  
Effective Dose ◽  
Health Effects ◽  
Organ Doses ◽  
X Ray ◽  
Order Of Magnitude ◽  
Radiation Induced ◽  
Cancer Types ◽  
Effective Doses ◽  
Senior Patients ◽  
Age And Sex

The radiation risks from a range of medical x-ray examinations (radiography, fluoroscopy, and computed tomography) were assessed as a function of the age and sex of the patient using risk models described in Publication 103 (ICRP, 2007) and UNSCEAR (2006, Annex A). Such estimates of risk based on typical organ doses were compared with those derived from effective doses using the International Commission on Radiological Protection's nominal risk coefficients. Methodologically similar but not identical dose and risk calculations were performed independently at the Institute of Radiation Hygiene (Russia) and the Health Protection Agency (UK), and led to similar conclusions. The radiogenic risk of stochastic health effects following various x-ray procedures varied significantly with the patient's age and sex, but to differing degrees depending on which body organs were irradiated. In general, the risks of radiation-induced stochastic health effects in children are estimated to be higher (by a factor of ⩽4) than in adults, and risks in senior patients are lower by a factor of ⩾10 relative to younger people. If risks are assessed on the basis of effective dose, they are underestimated for children of both sexes by a factor of ⩽4. This approach overestimates risks by a factor of ⩽3 for adults and about an order of magnitude for senior patients. The significant sex and age dependence of radiogenic risk for different cancer types is an important consideration for radiologists when planning x-ray examinations. Whereas effective dose was not intended to provide a measure of risk associated with such examinations, it may be sufficient to make simple adjustments to the nominal risk per unit effective dose to account for age and sex differences.

scholarly journals Radiation Risks in Cis-Lunar Space for a Solar Particle Event Similar to the February 1956 Event

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 107
Author(s):  
Fahad A. Zaman ◽  
Lawrence W. Townsend
Keyword(s):  
Effective Dose ◽  
Energy Transport ◽  
Radiation Transport ◽  
Organ Doses ◽  
Solar Particle Events ◽  
Solar Particle ◽  
Transport Code ◽  
On Line ◽  
Critical Organ ◽  
In Cis

Solar particle events (SPEs) can pose serious threats for future crewed missions to the Moon. Historically, there have been several extreme SPEs that could have been dangerous for astronauts, and thus analyzing their potential risk on humans is an important step towards space exploration. In this work, we study the effects of a well-known SPE that occurred on 23 February 1956 on a mission in cis-Lunar space. Estimates of the proton fluence spectra of the February 1956 event were obtained from three different parameterized models published within the past 12 years. The studied geometry consists of a female phantom in the center of spherical spacecraft shielded by aluminum area densities ranging from 0.4 to 40 g cm−2. The effective dose, along with lens, skin, blood forming organs, heart, and central nervous system doses, were tallied using the On Line Tool for the Assessment of Radiation In Space (OLTARIS), which utilizes the High Z and Energy TRansport code (HZETRN), a deterministic radiation transport code. Based on the parameterized models, the results herein show that thicknesses comparable to a spacesuit might not protect against severe health consequences from a February 1956 category event. They also show that a minimum aluminum shielding of around 20 g cm−2 is sufficient to keep the effective dose and critical organ doses below NASA’s permissible limits for such event. In addition, except for very thin shielding, the input models produced results that were within good agreement, where the doses obtained from the three proton fluence spectra tended to converge with slight differences as the shielding thickness increases.

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