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Radiation Safety for You and Your Patient
Published in Vikram S. Kashyap, Matthew Janko, Justin A. Smith, Endovascular Tools & Techniques Made Easy, 2020
George K. Zhou, Justin A. Smith, Benjamin Colvard
The biological effect and potential damage caused by ionizing radiation depends on the amount of energy absorbed and the sensitivity of the particular organ exposed. Absorbed dose refers to the quantity of energy from radiation absorbed per unit mass (Joules per kilogram); the unit for absorbed dose is the gray (Gy). Although absorbed dose can help us quantify radiation exposure, it does not reflect the extent of tissue damage because different tissues are differentially sensitive to damage by radiation. To quantify this, the term equivalent dose is used, which refers to the amount of biological damage incurred by a tissue/organ; the unit for equivalent dose is the sievert (Sv) and is directly proportional to the damage a tissue sustains from radiation. In most cases, gray and sievert are equivalent, with gray used to quantify radiation use for most endovascular procedures.
Our Radiation Environment
Published in T. D. Luckey, Radiation Hormesis, 2020
The units and common conversion factors of radiobiology are indicated in Appendix 1. The Bequerel (Bq) provides a readily understood simplification: 1 Bq = 1 disintegration/s. The old Curie (Ci) was complex: 1 Ci = 3.7 × 1010 disintegrations/s. The conversions are: 1 Bq = 27.0 pCi and 1 Ci = 37.0 GBq. The Gray (Gy) expresses the amount of energy in the form of radiation to which an organism is exposed; 1 Gy = 10,000 ergs administered per gram. Since radiation is usually measured in air at the point of entry, Gy values are usually slightly less than stated. The Sievert (Sv) indicates the absorbed radiation dose and depends heavily upon Q. Sv is most useful for exposures from internal sources. Sv depends upon mass, energy, dose, dose rate and absorption, and factors in Q. Since these are often nebulous, external particle beams are often expressed as Gy. Conversion from Gy to Sv is often arbitrary for particle rays.
Radiation Safety in Chiropractic Radiography
Published in Russell L. Wilson, Chiropractic Radiography and Quality Assurance Handbook, 2020
The film badges (or dosimeters) are changed on a monthly basis. The reports are monitored by the Radiographer of Palmer College. The Radiographer and Radiologists and Radiology Resident are the only personnel monitored; they are thus considered controlled personnel. The maximum legal exposure limit for these workers is 5 rem (0.05 Sievert) per year. The quarterly exposure limits have been eliminated with the current 10 CFR-20 regulations. ALARA requires that a limit be set below the legal limit. Most radiologic facilities set the limit at 10% of the legal limit (500 mrem or 0.005 Sv per year). This 10% below the limit is also the limit where film badges or personnel monitoring is required; 500 mrem is also the legal limit for exposure of declared-pregnant controlled personnel during the gestational period.
Dosimetry and uncertainty approaches for the million person study of low-dose radiation health effects: overview of the recommendations in NCRP Report No. 178
Published in International Journal of Radiation Biology, 2022
Lawrence T. Dauer, André Bouville, Richard E. Toohey, John D. Boice, Harold L. Beck, Keith F. Eckerman, Derek Hagemeyer, Richard W. Leggett, Michael T. Mumma, Bruce Napier, Kathy H. Pryor, Marvin Rosenstein, David A. Schauer, Sami Sherbini, Daniel O. Stram, James L. Thompson, John E. Till, R. Craig Yoder, Cary Zeitlin
Most records or personal dosimeter results reflect a single value of exposure or Hp(10) for a monitoring period. The exposure scenario and pathways should assess the applicability of this single value as being appropriate for all areas of the body. Many exposure conditions result in different body areas being irradiated at much different levels as happens when protective aprons are worn during fluoroscopic procedures or when source shielding configurations cause large spatial variations in dose rate. Regulatory guidance requires personal monitoring devices to be worn at the location of highest dose; therefore, the recorded dosimeter results may overstate the Hp(10) for some areas of the body. The derivation of organ doses from external irradiation assumes that an estimate exists of the quantity exposure or personal dose equivalent [Hp(10)]. For photons, the quantities assessed from personal monitoring dosimeters generally fall into two categories: early dosimeter data for which the quantity measured was exposure, generally measured at the surface of the body [expressed in roentgen (R)], and later data for which the quantity measured was Hp(10), initially expressed in rem and now expressed in sievert (Sv). Therefore, early dosimeter data should be converted from exposure to Hp(10).
Experimental study of potential adverse effects on the auditory system of rabbits exposed to short-term GSM-1800 radiation
Published in International Journal of Radiation Biology, 2021
Antigoni E. Kaprana, Ioannis O. Vardiambasis, Theodoros N. Kapetanakis, Melina P. Ioannidou, Christos D. Nikolopoulos, Grigorios E. Lyronis
Audiometric tests, such as the auditory brainstem response (ABR) and the otoacoustic emission (OAE) may provide reliable information about potential disturbances in hearing functions due to electromagnetic field (EMF) exposure (Kwon and Hämäläinen 2011). The effect of the exposure to radiofrequency (RF) radiation on the auditory pathways of humans (volunteers) was studied by many researchers via ABR measurements; several of them presented negative findings (Arai et al. 2003; Oysu et al. 2005; Sievert et al. 2005; Stefanics et al. 2007; Kwon et al. 2010a; Gupta et al. 2015), whereas some positive results, i.e. increased latency of certain waves, were reported by Kellenyi et al. (1999), Malla et al. (2012) and Khullar et al. (2013). Measurements of the evoked OAEs were carried out by Ozturan et al. (2002) without detecting any deterioration in hearing level caused by exposure to the EM waves emitted by a mobile phone. Several tests for the assessment of the auditory function such as the hearing threshold level, OAEs and auditory evoked potentials (AEPs) were conducted by Parazzini et al. (2009, 2010); no measurable immediate effects on the human auditory system were observed. However, measurements of the AEPs performed by Maby et al. (2005), resulted in significant differences on the temporal and frequency correlation coefficient variations with exposure to RF radiation.
Data independent acquisition mass spectrometry of irradiated mouse lung endothelial cells reveals a STAT-associated inflammatory response
Published in International Journal of Radiation Biology, 2020
Jos Philipp, Wolfgang Sievert, Omid Azimzadeh, Christine von Toerne, Fabian Metzger, Anton Posch, Daniela Hladik, Prabal Subedi, Gabriele Multhoff, Michael J. Atkinson, Soile Tapio
All experiments were approved by the responsible state agency (Regierung von Oberbayern, certificate no. 55.2-1-54-2532-191-14). They were in compliance with national law on animal experimentation and welfare and performed in accordance with institutional and ARRIVE guidelines. Female C57Bl/6 mice (Charles River Laboratories, Sulzfeld, Germany) aged 4–5 weeks were randomly allocated to the treatment groups (4 mice/group). Irradiation of the whole thorax was performed using a high-precision image-guided Small Animal Radiation Research Platform (SARRP, Xstrahl, Camberley, UK). The dosimetry was performed using a calibrated ionization chamber (International Atomic Energy Agency, Vienna, Austria; Technical Reports Series No. 398) and radiochromic films (Gafchromic EBT3, Ashland, Covington, KY), according to the manufacturer’s recommendations. The mice were anesthetized by isoflurane/oxygen inhalation for the duration of the treatment. The thorax was first visualized by CBCT to identify the required radiation field (60-kV and 0.8-mA photons filtered with aluminum 1 mm). The software SARRP control and Muriplan were used to precisely target thorax and estimate the radiation dose, respectively (Sievert et al. 2018). A single dose of 10 Gy was delivered using a 220 kV and 13 mA X-ray beam filtered with copper (0.15 mm). Control mice received sham irradiation using CBCT. The mice were housed in single ventilated cages under pathogen-free conditions while experimentation. In total, 32 mice were used in this study.