Essay Example on Regarding published studies on evaluation Radiation

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Regarding published studies on evaluation radiation doses for CT examinations Kanal et al 38 calculated the DRLs and median values of CTDIvol and DLP for CT from 1310727 of ten most common examinations in the United States They found an insignificant relation between the patient size and DRLs and achievable doses for head and neck examinations however the CTDIvol DLP and DRLs increased with patient s size for body examinations Toori et al 39 establishes local reference levels for patients undergoing common CT examinations Including chest sinus brain pelvic and abdomen in Iran They reported differing values of the DLP CTDIw and CTDIvol for the same examination among different centers For example the CTDIw for pelvic was ranged from 7 to 16 3 and the DRLs defined to be 11 mGy In 2014 Alzimami 40 assessed the dose in 182 paediatric patients undergoing abdomen chest and brain helical CT examinations in Sudan The range of age in Alzimami study range between one month and ten years and weight between 5 and 29 kg They reported a highest value of DLP for the brain with 321 mGy cm effective dose 2 05 mSv and found a significant relation between patient dose and technologist experience and CT protocol Concerning published studies on evaluation radiation doses during routine fluoroscopy examinations Wambani et al 41 reported 83 of kerma area product for 455 adult patients using the integrated measuring system were below international DRLs and 60 of 195 paediatric patients below international DRLs except the examination performed with longtime found to be above international DRLs 



Regarding the interventional radiology examinations Urairat et al 42 calculated the entrance skin dose to 120 patients undergoing brain arteriovenous malformations dural arteriovenous fistula transarterial oily chemoembolization and femoral angiography in Thailand using built in air kerma area product meter They found a difference between radiations doses in most interventional examinations but they detected the highest ESDs in therapeutic cerebral angiography examinations with about 363 cGy Regarding published studies on evaluating image quality and estimations radiation doses for mammography examinations Ślusarczyk Kacprzyk et al 43 calculated the MGD for patients in Poland for 47 systems using ACR accreditation phantom with methods described by Perry et all 24 They calculated the MGD for breast simulated by 4 5 cm of PMMA and reported only the large doses in computer radiography mammography systems comparing with several screen film and fully digital systems It is worth noting that Ślusarczyk Kacprzyk et al 43 noticed that the image quality in the fully digital systems higher than other systems despite the relatively low doses recorded Methodology not less than 1000 1004 Eight major hospitals in Najran will include in this study namely Maternity and Children Hospital King Khalid Hospital Najran University Hospital Najran General Hospital Najran Health Center National Guard Health Affairs Armed Forces Hospital Habona General Hospital and Sharurah Hospital SH to evaluate image quality and to measure the radiation doses for patients undergoing common examinations in X ray fluoroscopy mammography and CT For diagnostic x ray equipment the exposure parameters such as kVp mAs and focus to skin distance

FSD and the patients anthropometric data will record directly by the technologist at the time of examination The tube output will be measured using an Unfors Xi dosemeter ESD will calculate for five routine radiographic examinations abdomen AP chest AP skull AP pelvis AP and cervical spine LAT from the eight hospitals using DoseCal and CALDose software Regarding conventional x ray units this study will be a complementary to a previous one that evaluated the ESDs for chest and lumbar spine examinations 44 but on a scale covering all hospitals in the Najran area as well as using an additional software CALDose version X 5 0 to verify the obtained results The CALDose is stand for CALculation of Dose for X ray diagnosis and is Windows software based on EGSnrc Monte Carlo code calculation to determine the organ absorbed doses and cancer risks for patients undergoing to radiological procedures It s developed by the Department of Nuclear Energy Federal University of Pernambuco Brazil The software requires the user to input the patients anthropometric data and technical exposure recorded at the time of examination Based on the tube output of the x ray unit and entrance surface air kerma the software will calculate the incident air kerma This study will also be a complementary to a previous one that evaluated the CTDIw for chest and head examinations 45 and will be the second in a series of reviews the dose collects from all hospitals in Najran using the same fabricated phantoms developed locally in Najran University The radiation dose in CTs at all hospitals will be measured using an ionization chamber type Unfors Xi CT and the image quality will be evaluated using Gammex 464 ACR CT accreditation phantom

The quality of image will include evaluating the following CT number slice thickness position alignment CT number uniformity low and high contrast resolution The radiation dose in terms of MGD will be evaluated for all mammography systems in all hospitals with the same method described by Perry et al 24 The description of this method was explained below The standard breast can be simulated using 5 cm thickness of PMMA however it s recommended to calculate the glandular dose for different PMMA thicknesses The exposure parameters such as kVp mAs target and filter material in the automatic exposure control mode should be recorded after exposing 2 3 4 4 5 5 6 and 7 cm thickness of PMMA The average glandular dose AGD can be calculated to typical PMMA thickness by the following equation AGD Ka i g c s


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