scholarly journals An assessment of scattered radiation during fluoroscopic procedures in diagnostic radiology

2009 ◽  
Vol 24 (3) ◽  
pp. 204-208 ◽  
Author(s):  
Olivera Ciraj-Bjelac ◽  
Danijela Arandjic ◽  
Dusko Kosutic ◽  
Djordje Lazarevic
Keyword(s):  
Dose Rate ◽  
Scattered Radiation ◽  
Ionization Chamber ◽  
Diagnostic Radiology ◽  
X Ray ◽  
Dose Rates ◽  
Tube Arrangement ◽  
Vertical Beam ◽  
Exposure Conditions

The results of measurements of scattered radiation in the vicinity of a fluoroscopic X-ray facility are presented in this paper. Two different fluoroscopic systems, one with an undercouch tube and one with an overcouch tube, were compared. The dose rate was measured during the simulation of a fluoroscopy procedure, using an ionization chamber as a dosemeter. The distribution of scattered radiation has been determined and results show a much higher dose rate in cases of an overcouch tube arrangement. When X-ray units with an undercouch tube are concerned, under same exposure conditions, the dose rate is higher in cases of a vertical beam. Prior to the measurements, the ionization chamber was examined in order to evaluate its suitability as a survey meter used in diagnostic radiology. Measurements show that below 1.2 s, the ionization chamber gives an underestimation of dose rates. Therefore, in order to perform accurate measurements using this instrument, exposure times should be above 1.2 s.

scholarly journals Cu/Ce-co-Doped Silica Glass as Radioluminescent Material for Ionizing Radiation Dosimetry

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2611
Author(s):  
Jessica Bahout ◽  
Youcef Ouerdane ◽  
Hicham El Hamzaoui ◽  
Géraud Bouwmans ◽  
Mohamed Bouazaoui ◽  
...  
Keyword(s):  
Dose Rate ◽  
Silica Glass ◽  
Energy Levels ◽  
Sol Gel ◽  
Radiation Detection ◽  
Optical Signal ◽  
X Ray ◽  
Dose Rates ◽  
Integrated Intensities ◽  
Co Doped

Optically activated glasses are essential to the development of new radiation detection systems. In this study, a bulk glassy rod co-doped with Cu and Ce ions, was prepared via the sol-gel technique and was drawn at about 2000 °C into a cylindrical capillary rod to evaluate its optical and radioluminescence properties. The sample showed optical absorption and photoluminescence (PL) bands attributed to Cu+ and Ce3+ ions. The presence of these two ions inside the host silica glass matrix was also confirmed using PL kinetics measurements. The X-ray dose rate was remotely monitored via the radioluminescence (RL) signal emitted by the Cu/Ce scintillating sensor. In order to transport the optical signal from the irradiation zone to the detection located in the instrumentation zone, an optical transport fiber was spliced to the sample under test. This RL signal exhibited a linear behavior regarding the dose rate in the range at least between 1.1 mGy(SiO2)/s and 34 Gy(SiO2)/s. In addition, a spectroscopic analysis of this RL signal at different dose rates revealed that the same energy levels attributed to Cu+ and Ce3+ ions are involved in both the RL mechanism and the PL phenomenon. Moreover, integrated intensities of the RL sub-bands related to both Cu+ and Ce3+ ions depend linearly on the dose rate at least in the investigated range from 102 mGy(SiO2)/s up to 4725 mGy(SiO2)/s. The presence of Ce3+ ions also reduces the formation of HC1 color centers after X-ray irradiation.

Diagnostic radiology—Facility

2015 ◽  
Author(s):  
David G Sutton ◽  
Colin J Martin
Keyword(s):  
Radiation Protection ◽  
Scattered Radiation ◽  
Patient Dose ◽  
Diagnostic Radiology ◽  
X Ray ◽  
The Public ◽  
Room Design ◽  
Time Distance ◽  
Dose Constraints ◽  
Dose Levels

The exposure to radiation of staff and members of the public is restricted by seeking suitable compromises between the three basic elements of time, distance, and shielding. This chapter deals with the design of X-ray facilities to ensure that the distance and shielding elements are used appropriately. Criteria in the form of dose constraints for staff and the public based on the ALARP principle are used together with occupancies of adjacent areas to determine acceptable dose levels. Methods for calculating doses from workloads in terms of patient dose data are described. The results are then combined with the dose criteria to derive transmission requirements for protective barriers. Specific requirements for secondary scattered radiation and primary beams in radiography are considered. The methodology is described together with practical examples of room design for different X-ray techniques and elements of personnel radiation protection are discussed.

EVALUATION OF RADIATION DOSE IN DIFFERENT POSITIONS AROUND THE PATIENT TABLE DURING INTERVENTIONAL CARDIOLOGY PROJECTIONS

2019 ◽  
Vol 188 (2) ◽  
pp. 199-204
Author(s):  
Y Lahfi ◽  
A Ismail
Keyword(s):  
Radiation Dose ◽  
Radiation Exposure ◽  
Dose Rate ◽  
Radiation Protection ◽  
Interventional Cardiology ◽  
X Ray ◽  
Dose Rates ◽  
Patient Table ◽  
The Right

Abstract The aim of the present study was to evaluate the radiation exposure around the patient table as relative to the cardiologist position dose value. The dose rates at eight points presuming staff positions were measured for PA, LAO 30° and RAO 30° radiographic projections, and then normalized to the cardiologist’s position dose-rate value. The results show that in PA and RAO 30° projections, the normalized dose rate was higher by 9–22% at the right side of the table at a distance of 50 cm, while it was higher up to 31% at the left side for the same measured points in the LAO 30°. The differences of normalized dose rates for the both table sides were lower and decreased at farther positions. The obtained results correspond to the recommendations of staff radiation protection in Cath-labs with regards to X-ray tube and detector positions.

scholarly journals Study of scattered radiation during fluoroscopy in hip surgery

2016 ◽  
Vol 49 (4) ◽  
pp. 234-240
Author(s):  
Oksana Lesyuk ◽  
Patrick Emmanuel Sousa ◽  
Sónia Isabel do Espirito Santo Rodrigues ◽  
António Fernando Abrantes ◽  
Rui Pedro Pereira de Almeida ◽  
...  
Keyword(s):  
Health Care ◽  
Operating Room ◽  
Health Care Professionals ◽  
Scattered Radiation ◽  
Hip Surgery ◽  
Whole Body ◽  
X Ray ◽  
Dose Rates ◽  
Orthopedic Surgical Procedures ◽  
Low Levels

Abstract Objective: To measure the scattered radiation dose at different positions simulating hip surgery. Materials and Methods: We simulated fluoroscopy-assisted hip surgery in order to study the distribution of scattered radiation in the operating room. To simulate the patient, we used a anthropomorphic whole-body phantom, and we used an X-ray-specific detector to quantify the radiation. Radiographs were obtained with a mobile C-arm X-ray system in continuous scan mode, with the tube at 0º (configuration 1) or 90º (configuration 2). The operating parameters employed (voltage, current, and exposure time) were determined by a statistical analysis based on the observation of orthopedic surgical procedures involving the hip. Results: For all measurements, higher exposures were observed in configuration 2. In the measurements obtained as a function of height, the maximum dose rates observed were 1.167 (± 0.023) µSv/s and 2.278 (± 0.023) µSv/s in configurations 1 and 2, respectively, corresponding to the chest level of health care professionals within the operating room. Proximal to the patient, the maximum values were recorded in the position occupied by the surgeon. Conclusion: We can conclude that, in the scenario under study, health care professionals workers are exposed to low levels of radiation, and that those levels can be reduced through the use of personal protective equipment.

scholarly journals Effect of X-ray dose rates higher than 8 Gy/min on the functioning of cardiac implantable electronic devices

2020 ◽  
Vol 61 (3) ◽  
pp. 419-425 ◽  
Author(s):  
Kazuhiko Nakamura ◽  
Takahiro Aoyama ◽  
Naoki Kaneda ◽  
Masashi Otsuji ◽  
Yoshitaka Minami ◽  
...  
Keyword(s):  
Dose Rate ◽  
Treatment Plan ◽  
Electronic Devices ◽  
Normal Function ◽  
X Ray ◽  
Dose Rates ◽  
Cardiac Implantable Electronic Devices ◽  
Flattening Filter Free ◽  
Direct Irradiation ◽  
Flattening Filter

Abstract Direct irradiation may cause malfunctioning of cardiac implantable electronic devices (CIEDs). Therefore, a treatment plan that does not involve direct irradiation of CIEDs should be formulated. However, CIEDs may be directly exposed to radiation because of the sudden intrafractional movement of the patient. The probability of CIED malfunction reportedly depends on the dose rate; however, reports are only limited to dose rates ≤8 Gy/min. The purpose of this study was to investigate the effect of X-ray dose rates >8 Gy/min on CIED function. Four CIEDs were placed at the center of the radiation field and irradiated using 6 MV X-ray with flattening filter free (6 MV FFF) and 10 MV X-ray with flattening filter free (10 MV FFF). The dose rate was 4–14 Gy/min for the 6 MV FFF and 4–24 Gy/min for 10 MV FFF beams. CIED operation was evaluated with an electrocardiogram during each irradiation. Three CIEDs malfunctioned in the 6 MV FFF condition, and all four CIEDs malfunctioned in the 10 MV FFF condition, when the dose rate was >8 Gy/min. Pacing inhibition was the malfunction observed in all four CIEDs. Malfunction occurred simultaneously along with irradiation and simultaneously returned to normal function on stopping the irradiation. An X-ray dose rate >8 Gy/min caused a temporary malfunction due to interference. Therefore, clinicians should be aware of the risk of malfunction and manage patient movement when an X-ray dose rate >8 Gy/min is used for patients with CIEDs.

scholarly journals X-ray Dose Rate and Spectral Measurements during Ultrafast Laser Machining Using a Calibrated (High-Sensitivity) Novel X-ray Detector

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4397
Author(s):  
Philip Mosel ◽  
Pranitha Sankar ◽  
Jan Friedrich Düsing ◽  
Günter Dittmar ◽  
Thomas Püster ◽  
...  
Keyword(s):  
Dose Rate ◽  
Repetition Rate ◽  
Average Power ◽  
Radiation Shielding ◽  
Ultrafast Laser ◽  
Laser Machining ◽  
Detection Range ◽  
X Ray ◽  
Laser Parameters ◽  
Dose Rates

Ultrashort pulse laser machining is subject to increase the processing speeds by scaling average power and pulse repetition rate, accompanied with higher dose rates of X-ray emission generated during laser–matter interaction. In particular, the X-ray energy range below 10 keV is rarely studied in a quantitative approach. We present measurements with a novel calibrated X-ray detector in the detection range of 2–20 keV and show the dependence of X-ray radiation dose rates and the spectral emissions for different laser parameters from frequently used metals, alloys, and ceramics for ultrafast laser machining. Our investigations include the dose rate dependence on various laser parameters available in ultrafast laser laboratories as well as on industrial laser systems. The measured X-ray dose rates for high repetition rate lasers with different materials definitely exceed the legal limitations in the absence of radiation shielding.

Acute X-ray Lethality in the Mouse: Comparison of Ultrahigh Dose Rate with More Usual Dose Rates

Radiology ◽  
1967 ◽  
Vol 89 (2) ◽  
pp. 335-337
Author(s):  
William L. Caldwell ◽  
David H. Sloan
Keyword(s):  
Dose Rate ◽  
X Ray ◽  
Dose Rates ◽  
Usual Dose

PHOTON FIELD OF ~100–200 KEV FOR ENVIRONMENTAL DOSEMETER CALIBRATION

2020 ◽  
Vol 188 (4) ◽  
pp. 486-492
Author(s):  
S M Tajudin ◽  
Y Namito ◽  
T Sanami ◽  
H Hirayama
Keyword(s):  
Dose Rate ◽  
Low Dose ◽  
Gamma Source ◽  
X Ray ◽  
Dose Rates ◽  
Photon Field ◽  
Gamma Sources ◽  
Energy Dependent

Abstract As a reference photon field, several radionuclides have been used frequently, such as 241Am,137Cs and60 Co for calibration. These nuclides provide mono-energy photons for dosemeters covering few tens of keV–MeV. The main energy around 200 keV is important for both environmental and medical fields since the former should consider scattering photons and the later should measure photons from X-ray generator. In our previous work, a backscattered layout can provide a uniform photon field spectra and dose rate with an energy of 190 keV by using an affordable intensity 137 Cs gamma source. Several other quasi-monoenergetic photon fields in the range of 100–200 keV could be obtained by using several available gamma sources. Two calibrated environmental CsI(Tl) survey meters, Horiba PA-1000 and Mr. Gamma A2700, had been measured with the developed backscattered photon field to understand energy-dependent features in order to confirm dosemeter readings. Consequently, both scintillator instruments are sensitive for measurements of the relatively low dose rates at 190 keV.

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