Estimation of Radiation Effective Dose from Abdominal CT Examination Using Two Different Methods

Estimation of Radiation Effective Dose from Abdominal CT Examination Using Two Different Methods | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Estimation of Radiation Effective Dose from Abdominal CT Examination Using Two Different Methods Raed M.K. M.Ali This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7381034/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 27 Apr, 2026 Read the published version in Egyptian Journal of Radiology and Nuclear Medicine → Version 1 posted You are reading this latest preprint version Abstract Introduction: Since the introduction of computed tomography (CT), there has been a progressive concern about its associated radiation risk. This study aims to compare the radiation effective dose (ED) of abdominal CT examination calculated by two different methods. Material and Methods Dosimetric data of abdominal CT examination was used to calculate ED for 73 adult patients; 41 males and 32 females. For each participant the ED was calculated three times. The first and second times were by the use of DLP to ED conversion factors ( k -coefficients) which are published by the European Commission (EC) and that specifically published for SOMATOM Definition SA / Siemens CT machine. The other method includes the calculation of ED based on organ dose, which are obtained by CTDI vol to organ dose conversion factors. Results The ED calculated by both machine specific DLP to ED conversion factor and organ dose method tend to be comparable 7.96 mSv and 8.05 mSv, respectively. A smaller ED was obtained by the use EC’s DLP to ED conversion factor, 7.42 mSv. However, these variations are statistically non-significant. For all calculation methods, ED was higher for female patients than for male patients. Conclusion The abdominal CT ED estimated in this study was within the internationally recommended levels. However, sex-specific ED calculation may be recommended. CT abdomen radiation risk CT dosimentry organ dose Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Computed tomography (CT) is a non-invasive medical imaging tool. It is used to obtain high resolution three-dimensional images of internal human body structures (1, 2). Since the introduction of CT in 1971, the number of CT examinations has dramatically increased and the consequent radiation dose to patients has increased ( 3 , 4 ). It has been reported that the number of CT examinations in the United State (US) increased 20 times since the beginning of 1990s ( 5 ) wherein the annual number of CT examinations is approximately 85 million or more ( 6 ). Similarly, in the United Kingdom the number of CT examinations achieved by National Health Services (NHS) increased from approximately 1 million examinations during 1996 to slightly less than 6 million during 2019 ( 7 ). Between 2012 and 2022, the available number of CT units in most European countries increases with the highest increment was recorded in Cyprus which was 1.6 scanners per 100 000 residents ( 8 ). Overall, the annual worldwide number of CT examinations is approximately 400 million which constitute 9.6% of total radiographic examinations. However, CT examinations contribute to about 62% of the annual radiation collective dose to population from medical procedures ( 9 ). Therefore, justification and optimization of CT examinations are greatly important to ensure that the radiation doses and the consequent risk are As Low As Reasonably Practicable (ALARP) ( 1 , 10 ). Epidemiological studies reported that there is evidenced link between the exposure to low radiation does and cancer incidence. However the full mechanism of this link is not understood ( 11 , 12 ). The radiation dose from CT examinations is relatively high when compared to other radiological examinations. It has been reported that the radiation dose from CT examination of abdomen 100 to 250 times that caused by chest X-ray examination and this radiation dose equivalent to personal annual radiation does from natural and manmade resources. Richardson, Leuraud ( 13 ) reported that the excess relative rate of solid cancer mortality increases by 52% per Gray (Gy). For CT examinations, Cao, Ma ( 14 ) concluded that there is a positive correlation between radiation dose from CT examinations and the risk of cancer incidence. For instance, in the US previous studies mentioned that the radiation dose from CT examinations may contributes to approximately 2% of new cancer cases ( 11 , 15 ). Modern CT scanners report volumetric CT dose index (CTDI vol ) and dose-length product (DLP) as patient radiation dose indicators ( 6 ). CTDI vol represents the radiation absorbed dose received by the scanned volume. DLP represents the product of CTDI vol and scan length ( 16 ). Although these metrics are related to patient’s radiation dose and its associated risk, they cannot be used for other imaging modalities to compare the radiation risk from different radiological procedures ( 17 ). Alternatively, the International Commission on Radiological Protection (ICRP) recommended the used of effective dose (ED) which can be used to compare the radiation dose from different imaging modalities ( 18 ). ED considers the radiation dose received by different human body tissues and organs as well as their different radio-sensitivity ( 19 ). For the calculation of effective dose, the ICRP recommended the use of tissue weighting factors which are averaged across age and sex ( 18 ). For quick and easy estimation of effective dose from CT examinations, DLP to ED conversion factors, which are called k -coefficients, are used ( 20 ). Brady, Mirro ( 21 ) found that there are some differences between the effective doses calculated using ICRP tissue weighting factors with that calculated using DLP and k-coefficients. For both chest and abdominopelvic CT examinations, the ED calculated using DLP and k -coefficients method is overestimated with statistically significant differences. The differences were 21% and 42% for chest and abdominopelvic examinations, respectively. These variations may be attributed to that the CT pitch factor is not considered in k -coefficients estimation ( 21 ). One main concern in radiation protection is the large variations in radiation dose received by similar size patients when undergo same radiographic procedure ( 20 , 22 ). Previous studies reported that these variations may involve 2 to 10 times more radiation dose ( 22 ). Other studies reported more variations in radiation dose which may be 17 times ( 23 ) and may reach to 20 times ( 22 ). These variations may by recorded in different hospital and may be in same hospital in different radiographic facilities. Accordingly, the radiation protection authorities recommend the establishment of local and national diagnostic reference levels based on radiation dose data, collected by survey, for each radiographic procedure and these DRLs have regularly updated ( 18 , 24 ). For CT examinations the DRLs are established using CTDI vol , DLP and ED to ensure that the radiation dose is within the acceptable levels ( 20 ). The aim of current study is to evaluate the radiation dose received by patients undergoing abdominal CT examination as well as to compare the ED calculated by two different methods. Material and Methods This study involves the collection of dosimetric data for 73 adult patients underwent abdominal CT examinations retrospectively. A 56% of study participants were male and the other 44% were females. Before starting the work, the study was approved by the ethical committee at XXX University with document # MEC-196. For ethical considerations the hospital obtained verbal consent from patients to use their examination parameters for research purpose without an indication to their names. The data were collected from 4 CT units in 4 different hospitals. All of the CT machines were SOMATOM Definition SA from Siemens. The data, which are extracted from PACS database, include patients’ sex, CTDI vol DLP and mAs. A contrast study was required for 15 male and 6 female patients and subsequently those patients exposed to more than on scan. After data collection, the ED calculated using two different methods. The first method by the use of DLP and k -coefficients published by the European Commission ( 20 ) using the following equation: ED (mSv) = k -coefficient (mSv mGy − 1 cm − 1 ). DLP (mGy cm) Similarly, the same previous method is used to calculate ED but with different k -coefficient which are calculated specifically for SOMATOM Definition SA CT machine in Canada ( 17 ). The second method for ED calculation was by the use of organ dose obtained by CTDI vol to organ dose conversion factors derived by Monte Carlo simulation as previously published using the below Eq. (25, 26): Organ dose (mGy) = Organ dose coefficient (mGy/100 mAs mGy). CTDI vol (mGy) Then, these organs doses were used to calculate the effective dose as follow ( 18 ): ED = Σ wH Where H T is the radiation dose absorbed by the organ or tissue T and w T is the tissue weighting factor ( 18 ). Then, the three sets of ED data obtained by the two methods was analyses using SPSS software and Microsoft Excel to evaluate the statistical difference amongst them. Also, the statistical difference was estimated between males and females and between different hospitals. Finally, for comparison purpose between the three methods of effective dose calculation, the effective dose calculated by the use of organ dose data plotted against DLP to establish k -coefficient for abdominal CT examination and compared it with previously published k -coefficients used in this study. Results The data of seventy-three patients considered in this study was collected from four hospitals as presented in table (1). In all hospitals the male patients are more than females. Totally, they are 41 male and 32 females. The patients’ dosimtric data (mAs, CTDI vol and DLP) collected from PACS database presented in table (2). All dosimetric parameters indicated that radiation dose for female patients more than males. For example, the mean ± sd CTDI vol for females was 10.16 ± 3.73 mGy and that for males was 7.45 ± 3.03 mGy. Variations in dosimetric parameters are also seen amongst different hospitals and even in same hospital and this indicated by standard deviation (sd) values. The organs dose calculated from CTDI vol and conversion factors are presented in table (3). For male patients, the highest radiation dose received by colon, spleen, kidney and liver, respectively. The radiation doses received by these four organs were comparable with slight variations. Similarly for female patients the highest radiation dose received by colon. However, the second highest dose received by kidney. Then, spleen, stomach, small intestine and liver received comparable radiation doses. As previously mentioned in method section, for each patient considered in this study the ED in (mSv) was calculated three times. The generated ED data was compared in Figure (1). It can be seen that the highest ED was recorded using organ dose method. The comparison of effective dose between males and females calculated by the three methods demonstrate that the effective dose of female was higher than males for all calculation methods; Figure (2). For male patients, k -coefficient obtained by organ dose data was comparable to previously published k -coefficients. However, for females the obtained k -coefficient was slightly more than those previously published factors; see Figures (3) and ( 4 ). Discussion The comparison of dosimetric parameters recorded in this study with those reported in previously published work demonstrates some variations. The mAs values for female patients recorded in this study were higher than for males 210.09 ± 69.10 and 179.00 ± 72.02 mAs, respectively. These were slightly higher than those published by Masjedi, Omidi ( 11 ) which were 110 ± 98 mAs for female and 131 ± 124 mAs for male. However, the mAs values recorded in this study were comparable to sex averaged mAs published by Bagherzadeh, MirDerikvand ( 15 ) which was 199.33 ± 25.85 mAs. Similarly, the recorded mAs was within the range obtained by Dimitroukas, Metaxas ( 1 ); 100–400 mAs. The mean ± sd value of CTDI vol recorded in this study for male patients was comparable to previously published work. It was 7.45 ± 3.03 mGy in current study and 8 ± 3 mGy in a study by Almasri and Inayyem ( 4 ). Similarly, it was comparable to sex-averaged CTI vol obtained by EL Fahssi, Semghouli ( 27 ) which was 7.25 ± 2.68 mGy. However, for female patients participated in current study the mean ± sd CTDI vol was 10.16 ± 3.73mGy which was higher than that of male participants as well as more than that published in previous works ( 4 , 27 ). This may be attributed to the random selection of participants regardless their size and weight. It may also be attributed to the use of CT machines from different manufacturer in previous work wherein Dimitroukas, Metaxas ( 1 ) found 36% variation in CTDI vol recorded from different manufacturer CT machines. For both female and male patients participated in this study the maen ± sd DLP was higher than that obtained by other researchers ( 4 , 27 , 28 ). For instance, the DLP of abdominal CT examination documented by Abdul Karim, Hashim ( 28 ), which was 433.7 ± 140.9 mGy.cm, was the closest to that obtained in this study; 470.58 ± 228.94 and 525.74 ± 204.41 mGy.cm for male and female patients, respectively. Overall, the recorded DLP in this study was within the acceptable limit recommended by the European Commission ( 20 ) (780 mGy.cm). The radiation absorbed doses received by radio-sensitive organs, which are determined by the ICRP, for effective dose calculation were considered in this study. The organ radiation doses calculated in this study were higher than those documented by Brady, Mirro ( 29 ) because the maximum patients weight that they consider was 55 kg and this is inconsistent with size of current study participants. Similarly, the radiation dose received by stomach, colon, prostate and uterus calculated in current work were higher than those obtained by Almasri and Inayyem ( 4 ) who calculated the radiation dose received by these organs only. The three sets of ED calculated in current study show some variations; see Figure (1). However, these variations are statistically non-significant (p > 0.05) as estimated by Kruskal-Wallis test. The lowest effective doses were those calculated using DLP to ED conversion factor (0.015 mSv mGy − 1 cm − 1 ) published by the European Commission ( 20 ); 7.42 ± 3.28 mSv. In contrast, the highest ED values were those calculated using organ doses and tissue weighting factors; 8.05 ± 6.59 mSv. The effective doses calculated using machine specific factor (0.0161 mSv mGy − 1 cm − 1 ) tend to be comparable to those calculated by organs dose; 7.96 ± 3.52 mSv. For all effective dose calculation methods, effective dose was higher for female patients than male patients; see Figure (2). However, this difference was the highest for effective dose calculated by the use of organs dose and this agreed with the data obtained by Lee, Kim ( 30 ). For better understanding of these variations between male and female patients, k -coefficients were separately obtained for male (Fig. 3) and female (Fig. 4) patients using DLP and ED calculated using organ dose data. The extrapolated k -coefficients were 0.0156 and 0.0206 for male and female, respectively. Similarly the k -coefficients reported by Lee, Kim ( 30 ) which were 0.0155 mSv mGy − 1 cm − 1 for male and 0.0210 mSv mGy − 1 cm − 1 for female. In summary, compared to previously published works, the effective dose calculated in current study was either higher ( 1 , 4 , 11 , 27 , 28 ) or lower ( 15 , 31 ) but it is generally within the internationally acceptable levels (11 mSv) ( 9 ). Since the data obtained in this work based on CTDI vol to organ dose conversion factors published in previous work, the uncertainties in previous work may affect our data. Another point that needs to be improved in this work is that the use of more CT machines to minimize random errors and also consider CT machines from different manufacturers. Conclusion The abdominal CT effective dose estimated in this study was within the internationally recommended levels. According to effective dose calculation method, the obtained abdominal CT effective dose showed some variations. In general, the abdominal CT examination causes higher effective dose for females than for males. Subsequently, sex-specific effective dose calculation may be recommended particularly for abdominal CT examination. Declarations Author Contribution This article is achieved by a single author Funding Declaration This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. References Dimitroukas CP, Metaxas VI, Efthymiou FO, Kalogeropoulou CP, Zampakis PE, Panayiotakis GS. Patient dose audit in common CT examinations. Radiation Physics and Chemistry. 2022;192:109924. Golshan M, Ali B, Nima R, Reza M, Farzaneh J, Ali H. Evaluation of Cancer Risk Induced by Radiation Exposure from Normal Head CT Scans. Frontiers in Biomedical Technologies. 2023;10(3). IAEA. Quality Assurance Programme for Computed Tomography: Diagnostic and Therapy Applications. Vienna: INTERNATIONAL ATOMIC ENERGY AGENCY; 2012. Almasri H, Inayyem W. Evaluation of Radiation Doses for Patients Undergoing Abdominopelvic Computed Tomography Examination in Palestine. Japanese Journal of Health Physics. 2021;56(2):75-9. Costello JE, Cecava ND, Tucker JE, Bau JL. CT Radiation Dose: Current Controversies and Dose Reduction Strategies. American Journal of Roentgenology. 2013;201(6):1283-90. Sharma S, Kapadia A, Fu W, Abadi E, Segars WP, Samei E. A real-time Monte Carlo tool for individualized dose estimations in clinical CT. Physics in Medicine & Biology. 2019;64(21):215020. UKHealthSecurityAgency. UKHSA-RCE-1: doses from computed tomography (CT) exams in the UK: 2019 review. UK: UK Health Security Agency; 2022. EurostatStatisticsExplained. Healthcare resource statistics - technical resources and medical technology 2024 [updated 2024. Available from: https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Healthcare_resource_statistics_-_technical_resources_and_medical_technology&oldid=452031#Use_of_medical_technology. Radiation UNSCotEoA. Sources, Effects and Risks of Ionizing Radiation, United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2020/2021 Report, Volume IV: United Nations; 2022. TheIndustryRadiologicalProtectionCo-ordinationGroup(IRPCG). The Application of ALARP to Radiological Risk: A Nuclear Industry Good Practice Guide. 2012. Masjedi H, Omidi R, Zamani H, Perota G, Zare MH. Radiation dose and risk of exposure-induced death associated with common computed tomography procedures in Yazd Province. European Journal of Radiology. 2020;126:108932. NAS N. Health Risks from Exposure to Low Levels of Ionizing Radiation: BEIR VII – Phase 2. Washington: National Academies Press; 2006. Richardson DB, Leuraud K, Laurier D, Gillies M, Haylock R, Kelly-Reif K, et al. Cancer mortality after low dose exposure to ionising radiation in workers in France, the United Kingdom, and the United States (INWORKS): cohort study. Bmj. 2023;382:e074520. Cao CF, Ma KL, Shan H, Liu TF, Zhao SQ, Wan Y, et al. CT Scans and Cancer Risks: A Systematic Review and Dose-response Meta-analysis. BMC cancer. 2022;22(1):1238. Bagherzadeh S, MirDerikvand A, MohammadSharifi A. Evaluation of radiation dose and radiation-induced cancer risk associated with routine CT scan examinations. Radiation Physics and Chemistry. 2024;217:111521. ICRP. Managing Patient Dose in Multi-Detector Computed Tomography (MDCT). ICRP Publication 102. Ann ICRP. 2007;37(1). Elbakri IA, Kirkpatrick IDC. Dose-Length Product to Effective Dose Conversion Factors for Common Computed Tomography Examinations Based on Canadian Clinical Experience. Canadian Association of Radiologists Journal. 2013;64(1):15-7. ICRP. The 2007 Recommendations of the International Commission on Radiological Protection (Publication 103). Annals of the ICRP. 2007;37(2-4):1-332. McCollough CH, Chen GH, Kalender W, Leng S, Samei E, Taguchi K, et al. Achieving routine submillisievert CT scanning: report from the summit on management of radiation dose in CT. Radiology. 2012;264(2):567-80. EuropeanCommission. European guidelines on quality criteria for computed tomography: Publications Office; 2000. Brady SL, Mirro AE, Moore BM, Kaufman RA. How to Appropriately Calculate Effective Dose for CT Using Either Size-Specific Dose Estimates or Dose-Length Product. American Journal of Roentgenology. 2015;204(5):953-8. Muhogora WE, Ahmed NA, Almosabihi A, Alsuwaidi JS, Beganovic A, Ciraj-Bjelac O, et al. Patient Doses in Radiographic Examinations in 12 Countries in Asia, Africa, and Eastern Europe: Initial Results from IAEA Projects. American Journal of Roentgenology. 2008;190(6):1453-61. Abuzaid MM, Elshami W, Sulieman A, Bradley D. Cumulative radiation exposure, effective and organ dose estimation from multiple head CT scans in stroke patients. Radiation Physics and Chemistry. 2022;199:110306. ICRP. Diagnostic Reference Levels in Medical Imaging. ICRP Publication 135 Ann ICRP. 2017;46(1). Lee C, Kim KP, Long D, Fisher R, Tien C, Simon SL, et al. Organ doses for reference adult male and female undergoing computed tomography estimated by Monte Carlo simulations. Medical physics. 2011;38(3):1196-206. Lee C, Kim KP, Long DJ, Bolch WE. Organ doses for reference pediatric and adolescent patients undergoing computed tomography estimated by Monte Carlo simulation. Medical physics. 2012;39(4):2129-46. EL Fahssi M, Semghouli S, Amaoui B, Jroundi L, Çaoui M. Patient radiation doses from adult CT examinations at the Souss Massa Regional Hospital. Radioprotection. 2024;59(1):13-8. Abdul Karim MK, Hashim S, Sabarudin S, Bradley D, Ashiqin N. Evaluating organ dose and radiation risk of routine CT examinations in Johor Malaysia. 2016;45:567-73. Brady SL, Mirro AE, Moore BM, Kaufman RA. How to Appropriately Calculate Effective Dose for CT Using Either Size-Specific Dose Estimates or Dose-Length Product. AJR American journal of roentgenology. 2015;204(5):953-8. Lee SK, Kim JS, Yoon SW, Kim JM. Development of CT Effective Dose Conversion Factors from Clinical CT Examinations in the Republic of Korea. Diagnostics (Basel). 2020;10(9). Smith-Bindman R, Lipson J, Marcus R, Kim KP, Mahesh M, Gould R, et al. Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer. Arch Intern Med. 2009;169(22):2078-86. Tables Table (1) Presents the number of patients as well as their sex as collected from the four hospitals. Sex Hospital Total Hosp. 1 Hosp. 2 Hosp. 3 Hosp. 4 Male 6 3 17 15 41 Female 4 7 11 10 32 Total 10 10 28 25 73 Table (2) Presents the dosimtric data (mean ± standard deviation) for the seventy-three patients considered in this study. Sex Parameter Hosp. 1 Hosp. 2 Hosp. 3 Hosp. 4 All patients Male mAs 173.83 ± 32.70 137.67 ± 29.26 199.59 ± 86.32 166.00 ± 68.75 179.00 ± 72.02 CTDIvol 13.27 ± 2.51 6.13 ± 1.32 8.87 ± 3.80 7.45 ± 3.03 7.45 ± 3.03 DLP 631.00 ± 155.35 288.2 ± 60.56 501.12 ± 244.53 408.27 ± 220.96 470.58 ± 228.94 Female mAs 195.25 ± 53.76 158.71 ± 38.76 288.64 ± 79.19 231.60 ± 66.54 210.09 ± 69.10 CTDIvol 14.91 ± 4.09 7.08 ± 1.73 10.20 ± 3.51 10.36 ± 3.02 10.16 ± 3.73 DLP 646.25 ± 229.62 353.23 ± 96.45 572.91± 216.66 546.40 ± 187.59 525.74 ± 204.41 Table (3) Presents the calculated organ dose (mGy) for males and females participated in current study. organ Male Female (mean±sd) Range (min.–max.) (mean±sd) Range (min.–max.) Brain 0.02 ± 0.02 0.00 - 0.11 0.03 ± 0.02 0.00 - 0.09 Salivary gland 0.04 ± 0.04 0.01 - 0.22 0.07 ± 0.05 0.01 - 0.19 Thyroid 0.17 ± 0.16 0.03 - 0.97 0.27 ± 0.18 0.04 - 0.70 Breast 9.11 ± 8.83 1.63 - 54.32 8.39 ± 5.43 1.29 - 22.76 Lung 3.49 ± 3.37 0.62 - 20.56 4.17 ± 2.72 0.64 - 11.19 Liver 11.31 ± 10.91 2.00 - 66.66 16.49 ± 10.71 2.53 - 44.44 oesophagus 2.63 ± 2.52 0.46 - 15.26 4.11 ± 2.69 0.62 - 10.93 Stomach 10.84 ± 10.45 1.91 - 63.74 16.76 ± 10.88 2.57 - 45.14 Colon 11.82 ± 11.40 2.09 - 69.69 20.13 ± 13.02 3.11 - 54.67 Bladder 5.98 ± 5.75 1.05 - 34.84 9.34 ± 6.10 1.42 - 24.94 Testes / Ovaries 1.24 ± 1.19 0.21 - 7.14 12.06 ± 7.90 1.83 - 32.10 Bone marrow 3.85 ± 3.69 0.67 - 22.18 6.14 ± 4.06 0.92 - 16.18 Skin 3.63 ± 3.53 0.66 - 21.86 4.91 ± 3.16 0.76 - 13.43 Oral mucosa * 0.04 ± 0.04 0.01 - 0.22 0.10 ± 0.06 0.01 - 0.26 Heart * 3.73 ± 3.59 0.66 - 21.86 5.11 ± 3.33 0.78 - 13.68 Thymus * 0.41 ± 0.39 0.07 - 2.27 0.59 ± 0.39 0.09 - 1.53 Pancreas * 9.09 ± 8.74 1.59 - 52.92 14.82 ± 9.69 2.25 - 39.58 Spleen * 11.48 ± 11.10 2.04 - 68.07 16.97 ± 10.99 2.61 - 45.97 Gallbladder * 9.84 ± 9.46 1.72 - 57.35 14.55 ± 9.52 2.21 - 38.81 Adrenal gland * 9.16 ± 8.81 1.60 - 53.46 13.13 ± 8.59 1.99 - 35.04 Kidney * 11.44 ± 11.02 2.01 - 67.09 18.10 ± 11.77 2.77 - 48.66 Small intestine * 9.88 ± 9.50 1.73 - 57.68 16.58 ± 10.79 2.53 - 44.50 Prostate * / Uterus * 1.40 ±1.34 0.24 - 8.01 9.56 ± 6.29 1.44 - 25.32 Muscle * 4.12 ± 3.98 0.73 - 24.46 5.68 ± 3.68 0.87 - 15.34 * Indicate other organs in effective dose calculation Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 27 Apr, 2026 Read the published version in Egyptian Journal of Radiology and Nuclear Medicine → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7381034","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":510420332,"identity":"ef0169c5-f340-4a8d-8a31-e7dd549787da","order_by":0,"name":"Raed M.K. M.Ali","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABEUlEQVRIiWNgGAWjYJACCQaGBAaGG4wNDB8YGAwYmA8AxdjAiLAWxhkgLWwJRGthYGDmQdaCC5i3Hz546wZDmjzf7ebWzbZtNsYGx5gfMHwoO8zAx56AVYvMmbRk6xyGHMOZdw623c5tSzMzOMZmwDjj3GEGNp4HOByVYyadw1DBuOFGIkjLYRuD+w0GzLxtQC0S2G2R4H//DaTFHqzFEqTlGPsH5r/4tEjksAG15CSCtTC2HQY6jMeAmRGvlmfG1jkGackzgVpu9pxLM5Y8xlNwsOdcOg9Ov/AnP7ydU5Fs23cj/dmNH2U2hn3H2Dc++FFmLSffjt0WCDBA4x8AYh5wbJEKyNAyCkbBKBgFwxEAACmuYM0g25W5AAAAAElFTkSuQmCC","orcid":"","institution":"University of Kufa","correspondingAuthor":true,"prefix":"","firstName":"Raed","middleName":"M.K.","lastName":"M.Ali","suffix":""}],"badges":[],"createdAt":"2025-08-15 11:38:32","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7381034/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7381034/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s43055-026-01755-7","type":"published","date":"2026-04-27T15:57:11+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":90883829,"identity":"68d33202-b89b-4437-8ce2-4c10e7f88bd9","added_by":"auto","created_at":"2025-09-09 09:55:58","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":22492,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCompares the calculated mean effective using different methods.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7381034/v1/4f34c98f771624acbef21c5a.jpg"},{"id":90883830,"identity":"d590dfc0-11df-43a4-b5bf-45930271ce07","added_by":"auto","created_at":"2025-09-09 09:55:59","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":29096,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCompares the effective dose of females and males calculated by the three methods.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Figure2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7381034/v1/0f73a91b79c6141db96d0c7d.jpg"},{"id":90883835,"identity":"d29707a8-80ad-4b1d-910f-757f42270191","added_by":"auto","created_at":"2025-09-09 09:55:59","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":160465,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eObtains \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003ek\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e-coefficient for abdominal CT examination for male patients.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Figure3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7381034/v1/0ebca73424f3774fc532b777.jpg"},{"id":90883838,"identity":"361a99dd-8d09-4d0c-ae02-87b89a2c8658","added_by":"auto","created_at":"2025-09-09 09:55:59","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":143354,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eObtains \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003ek\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e-coefficient for abdominal CT examination for female patients.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"Figure4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7381034/v1/8bee7635edfd0b993bc6cb7d.jpg"},{"id":108437560,"identity":"d3c4d953-578b-4a48-be50-0ceee27468d4","added_by":"auto","created_at":"2026-05-04 15:59:14","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":688470,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7381034/v1/c4d7b24d-281e-421d-8f00-a6fd88e4a696.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Estimation of Radiation Effective Dose from Abdominal CT Examination Using Two Different Methods","fulltext":[{"header":"Introduction","content":"\u003cp\u003eComputed tomography (CT) is a non-invasive medical imaging tool. It is used to obtain high resolution three-dimensional images of internal human body structures (1, 2). Since the introduction of CT in 1971, the number of CT examinations has dramatically increased and the consequent radiation dose to patients has increased (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). It has been reported that the number of CT examinations in the United State (US) increased 20 times since the beginning of 1990s (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e) wherein the annual number of CT examinations is approximately 85\u0026nbsp;million or more (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Similarly, in the United Kingdom the number of CT examinations achieved by National Health Services (NHS) increased from approximately 1\u0026nbsp;million examinations during 1996 to slightly less than 6\u0026nbsp;million during 2019 (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Between 2012 and 2022, the available number of CT units in most European countries increases with the highest increment was recorded in Cyprus which was 1.6 scanners per 100 000 residents (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Overall, the annual worldwide number of CT examinations is approximately 400\u0026nbsp;million which constitute 9.6% of total radiographic examinations. However, CT examinations contribute to about 62% of the annual radiation collective dose to population from medical procedures (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). Therefore, justification and optimization of CT examinations are greatly important to ensure that the radiation doses and the consequent risk are As Low As Reasonably Practicable (ALARP) (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eEpidemiological studies reported that there is evidenced link between the exposure to low radiation does and cancer incidence. However the full mechanism of this link is not understood (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). The radiation dose from CT examinations is relatively high when compared to other radiological examinations. It has been reported that the radiation dose from CT examination of abdomen 100 to 250 times that caused by chest X-ray examination and this radiation dose equivalent to personal annual radiation does from natural and manmade resources. Richardson, Leuraud (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e) reported that the excess relative rate of solid cancer mortality increases by 52% per Gray (Gy). For CT examinations, Cao, Ma (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e) concluded that there is a positive correlation between radiation dose from CT examinations and the risk of cancer incidence. For instance, in the US previous studies mentioned that the radiation dose from CT examinations may contributes to approximately 2% of new cancer cases (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eModern CT scanners report volumetric CT dose index (CTDI\u003csub\u003evol\u003c/sub\u003e) and dose-length product (DLP) as patient radiation dose indicators (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). CTDI\u003csub\u003evol\u003c/sub\u003e represents the radiation absorbed dose received by the scanned volume. DLP represents the product of CTDI\u003csub\u003evol\u003c/sub\u003e and scan length (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e). Although these metrics are related to patient\u0026rsquo;s radiation dose and its associated risk, they cannot be used for other imaging modalities to compare the radiation risk from different radiological procedures (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e). Alternatively, the International Commission on Radiological Protection (ICRP) recommended the used of effective dose (ED) which can be used to compare the radiation dose from different imaging modalities (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). ED considers the radiation dose received by different human body tissues and organs as well as their different radio-sensitivity (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). For the calculation of effective dose, the ICRP recommended the use of tissue weighting factors which are averaged across age and sex (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). For quick and easy estimation of effective dose from CT examinations, DLP to ED conversion factors, which are called \u003cem\u003ek\u003c/em\u003e-coefficients, are used (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). Brady, Mirro (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e) found that there are some differences between the effective doses calculated using ICRP tissue weighting factors with that calculated using DLP and k-coefficients. For both chest and abdominopelvic CT examinations, the ED calculated using DLP and \u003cem\u003ek\u003c/em\u003e-coefficients method is overestimated with statistically significant differences. The differences were 21% and 42% for chest and abdominopelvic examinations, respectively. These variations may be attributed to that the CT pitch factor is not considered in \u003cem\u003ek\u003c/em\u003e-coefficients estimation (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eOne main concern in radiation protection is the large variations in radiation dose received by similar size patients when undergo same radiographic procedure (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). Previous studies reported that these variations may involve 2 to 10 times more radiation dose (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). Other studies reported more variations in radiation dose which may be 17 times (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e) and may reach to 20 times (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). These variations may by recorded in different hospital and may be in same hospital in different radiographic facilities. Accordingly, the radiation protection authorities recommend the establishment of local and national diagnostic reference levels based on radiation dose data, collected by survey, for each radiographic procedure and these DRLs have regularly updated (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). For CT examinations the DRLs are established using CTDI\u003csub\u003evol\u003c/sub\u003e, DLP and ED to ensure that the radiation dose is within the acceptable levels (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe aim of current study is to evaluate the radiation dose received by patients undergoing abdominal CT examination as well as to compare the ED calculated by two different methods.\u003c/p\u003e"},{"header":"Material and Methods","content":"\u003cp\u003eThis study involves the collection of dosimetric data for 73 adult patients underwent abdominal CT examinations retrospectively. A 56% of study participants were male and the other 44% were females. Before starting the work, the study was approved by the ethical committee at XXX University with document # MEC-196. For ethical considerations the hospital obtained verbal consent from patients to use their examination parameters for research purpose without an indication to their names.\u003c/p\u003e\u003cp\u003eThe data were collected from 4 CT units in 4 different hospitals. All of the CT machines were SOMATOM Definition SA from Siemens. The data, which are extracted from PACS database, include patients\u0026rsquo; sex, CTDI\u003csub\u003evol\u003c/sub\u003e DLP and mAs. A contrast study was required for 15 male and 6 female patients and subsequently those patients exposed to more than on scan.\u003c/p\u003e\u003cp\u003eAfter data collection, the ED calculated using two different methods. The first method by the use of DLP and \u003cem\u003ek\u003c/em\u003e-coefficients published by the European Commission (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e) using the following equation:\u003c/p\u003e\u003cp\u003e\u003cb\u003eED (mSv)\u0026thinsp;=\u003c/b\u003e\u0026thinsp;\u003cb\u003ek\u003c/b\u003e\u003cb\u003e-coefficient (mSv mGy\u003c/b\u003e\u003csup\u003e\u003cb\u003e\u0026minus;\u0026thinsp;1\u003c/b\u003e\u003c/sup\u003e \u003cb\u003ecm\u003c/b\u003e\u003csup\u003e\u003cb\u003e\u0026minus;\u0026thinsp;1\u003c/b\u003e\u003c/sup\u003e\u003cb\u003e). DLP (mGy cm)\u003c/b\u003e\u003c/p\u003e\u003cp\u003eSimilarly, the same previous method is used to calculate ED but with different \u003cem\u003ek\u003c/em\u003e-coefficient which are calculated specifically for SOMATOM Definition SA CT machine in Canada (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThe second method for ED calculation was by the use of organ dose obtained by CTDI\u003csub\u003evol\u003c/sub\u003e to organ dose conversion factors derived by Monte Carlo simulation as previously published using the below Eq.\u0026nbsp;(25, 26):\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eOrgan dose (mGy)\u0026thinsp;=\u0026thinsp;Organ dose coefficient (mGy/100 mAs mGy). CTDI\u003csub\u003evol\u003c/sub\u003e (mGy)\u003c/h2\u003e\u003cp\u003eThen, these organs doses were used to calculate the effective dose as follow (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e):\u003c/p\u003e\u003c/div\u003e\n\u003ch3\u003eED = Σ wH\u003c/h3\u003e\n\u003cp\u003eWhere H\u003csub\u003eT\u003c/sub\u003e is the radiation dose absorbed by the organ or tissue T and w\u003csub\u003eT\u003c/sub\u003e is the tissue weighting factor (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eThen, the three sets of ED data obtained by the two methods was analyses using SPSS software and Microsoft Excel to evaluate the statistical difference amongst them. Also, the statistical difference was estimated between males and females and between different hospitals.\u003c/p\u003e\u003cp\u003eFinally, for comparison purpose between the three methods of effective dose calculation, the effective dose calculated by the use of organ dose data plotted against DLP to establish \u003cem\u003ek\u003c/em\u003e-coefficient for abdominal CT examination and compared it with previously published \u003cem\u003ek\u003c/em\u003e-coefficients used in this study.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eThe data of seventy-three patients considered in this study was collected from four hospitals as presented in table (1). In all hospitals the male patients are more than females. Totally, they are 41 male and 32 females.\u003c/p\u003e\n\u003cp\u003eThe patients\u0026rsquo; dosimtric data (mAs, CTDI\u003csub\u003evol\u003c/sub\u003e and DLP) collected from PACS database presented in table (2). All dosimetric parameters indicated that radiation dose for female patients more than males. For example, the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;sd CTDI\u003csub\u003evol\u003c/sub\u003e for females was 10.16\u0026thinsp;\u0026plusmn;\u0026thinsp;3.73 mGy and that for males was 7.45\u0026thinsp;\u0026plusmn;\u0026thinsp;3.03 mGy. Variations in dosimetric parameters are also seen amongst different hospitals and even in same hospital and this indicated by standard deviation (sd) values.\u003c/p\u003e\n\u003cp\u003eThe organs dose calculated from CTDI\u003csub\u003evol\u003c/sub\u003e and conversion factors are presented in table (3). For male patients, the highest radiation dose received by colon, spleen, kidney and liver, respectively. The radiation doses received by these four organs were comparable with slight variations. Similarly for female patients the highest radiation dose received by colon. However, the second highest dose received by kidney. Then, spleen, stomach, small intestine and liver received comparable radiation doses.\u003c/p\u003e\n\u003cp\u003eAs previously mentioned in method section, for each patient considered in this study the ED in (mSv) was calculated three times. The generated ED data was compared in Figure (1). It can be seen that the highest ED was recorded using organ dose method.\u003c/p\u003e\n\u003cp\u003eThe comparison of effective dose between males and females calculated by the three methods demonstrate that the effective dose of female was higher than males for all calculation methods; Figure (2).\u003c/p\u003e\n\u003cp\u003eFor male patients, \u003cem\u003ek\u003c/em\u003e-coefficient obtained by organ dose data was comparable to previously published \u003cem\u003ek\u003c/em\u003e-coefficients. However, for females the obtained \u003cem\u003ek\u003c/em\u003e-coefficient was slightly more than those previously published factors; see Figures (3) and (\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe comparison of dosimetric parameters recorded in this study with those reported in previously published work demonstrates some variations.\u003c/p\u003e\n\u003cp\u003eThe mAs values for female patients recorded in this study were higher than for males 210.09\u0026thinsp;\u0026plusmn;\u0026thinsp;69.10 and 179.00\u0026thinsp;\u0026plusmn;\u0026thinsp;72.02 mAs, respectively. These were slightly higher than those published by Masjedi, Omidi (\u003cspan class=\"CitationRef\"\u003e11\u003c/span\u003e) which were 110\u0026thinsp;\u0026plusmn;\u0026thinsp;98 mAs for female and 131\u0026thinsp;\u0026plusmn;\u0026thinsp;124 mAs for male. However, the mAs values recorded in this study were comparable to sex averaged mAs published by Bagherzadeh, MirDerikvand (\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e) which was 199.33\u0026thinsp;\u0026plusmn;\u0026thinsp;25.85 mAs. Similarly, the recorded mAs was within the range obtained by Dimitroukas, Metaxas (\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e); 100\u0026ndash;400 mAs.\u003c/p\u003e\n\u003cp\u003eThe mean\u0026thinsp;\u0026plusmn;\u0026thinsp;sd value of CTDI\u003csub\u003evol\u003c/sub\u003e recorded in this study for male patients was comparable to previously published work. It was 7.45\u0026thinsp;\u0026plusmn;\u0026thinsp;3.03 mGy in current study and 8\u0026thinsp;\u0026plusmn;\u0026thinsp;3 mGy in a study by Almasri and Inayyem (\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e). Similarly, it was comparable to sex-averaged CTI\u003csub\u003evol\u003c/sub\u003e obtained by EL Fahssi, Semghouli (\u003cspan class=\"CitationRef\"\u003e27\u003c/span\u003e) which was 7.25\u0026thinsp;\u0026plusmn;\u0026thinsp;2.68 mGy. However, for female patients participated in current study the mean\u0026thinsp;\u0026plusmn;\u0026thinsp;sd CTDI\u003csub\u003evol\u003c/sub\u003e was 10.16\u0026thinsp;\u0026plusmn;\u0026thinsp;3.73mGy which was higher than that of male participants as well as more than that published in previous works (\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e27\u003c/span\u003e). This may be attributed to the random selection of participants regardless their size and weight. It may also be attributed to the use of CT machines from different manufacturer in previous work wherein Dimitroukas, Metaxas (\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e) found 36% variation in CTDI\u003csub\u003evol\u003c/sub\u003e recorded from different manufacturer CT machines.\u003c/p\u003e\n\u003cp\u003eFor both female and male patients participated in this study the maen\u0026thinsp;\u0026plusmn;\u0026thinsp;sd DLP was higher than that obtained by other researchers (\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e). For instance, the DLP of abdominal CT examination documented by Abdul Karim, Hashim (\u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e), which was 433.7\u0026thinsp;\u0026plusmn;\u0026thinsp;140.9 mGy.cm, was the closest to that obtained in this study; 470.58\u0026thinsp;\u0026plusmn;\u0026thinsp;228.94 and 525.74\u0026thinsp;\u0026plusmn;\u0026thinsp;204.41 mGy.cm for male and female patients, respectively. Overall, the recorded DLP in this study was within the acceptable limit recommended by the European Commission (\u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e) (780 mGy.cm).\u003c/p\u003e\n\u003cp\u003eThe radiation absorbed doses received by radio-sensitive organs, which are determined by the ICRP, for effective dose calculation were considered in this study. The organ radiation doses calculated in this study were higher than those documented by Brady, Mirro (\u003cspan class=\"CitationRef\"\u003e29\u003c/span\u003e) because the maximum patients weight that they consider was 55 kg and this is inconsistent with size of current study participants. Similarly, the radiation dose received by stomach, colon, prostate and uterus calculated in current work were higher than those obtained by Almasri and Inayyem (\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e) who calculated the radiation dose received by these organs only.\u003c/p\u003e\n\u003cp\u003eThe three sets of ED calculated in current study show some variations; see Figure (1). However, these variations are statistically non-significant (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05) as estimated by Kruskal-Wallis test. The lowest effective doses were those calculated using DLP to ED conversion factor (0.015 mSv mGy\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) published by the European Commission (\u003cspan class=\"CitationRef\"\u003e20\u003c/span\u003e); 7.42\u0026thinsp;\u0026plusmn;\u0026thinsp;3.28 mSv. In contrast, the highest ED values were those calculated using organ doses and tissue weighting factors; 8.05\u0026thinsp;\u0026plusmn;\u0026thinsp;6.59 mSv. The effective doses calculated using machine specific factor (0.0161 mSv mGy\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) tend to be comparable to those calculated by organs dose; 7.96\u0026thinsp;\u0026plusmn;\u0026thinsp;3.52 mSv.\u003c/p\u003e\n\u003cp\u003eFor all effective dose calculation methods, effective dose was higher for female patients than male patients; see Figure (2). However, this difference was the highest for effective dose calculated by the use of organs dose and this agreed with the data obtained by Lee, Kim (\u003cspan class=\"CitationRef\"\u003e30\u003c/span\u003e). For better understanding of these variations between male and female patients, \u003cem\u003ek\u003c/em\u003e-coefficients were separately obtained for male (Fig. 3) and female (Fig. 4) patients using DLP and ED calculated using organ dose data. The extrapolated \u003cem\u003ek\u003c/em\u003e-coefficients were 0.0156 and 0.0206 for male and female, respectively. Similarly the \u003cem\u003ek\u003c/em\u003e-coefficients reported by Lee, Kim (\u003cspan class=\"CitationRef\"\u003e30\u003c/span\u003e) which were 0.0155 mSv mGy\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for male and 0.0210 mSv mGy\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for female.\u003c/p\u003e\n\u003cp\u003eIn summary, compared to previously published works, the effective dose calculated in current study was either higher (\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e) or lower (\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e31\u003c/span\u003e) but it is generally within the internationally acceptable levels (11 mSv) (\u003cspan class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e\n\u003cp\u003eSince the data obtained in this work based on CTDI\u003csub\u003evol\u003c/sub\u003e to organ dose conversion factors published in previous work, the uncertainties in previous work may affect our data. Another point that needs to be improved in this work is that the use of more CT machines to minimize random errors and also consider CT machines from different manufacturers.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe abdominal CT effective dose estimated in this study was within the internationally recommended levels. According to effective dose calculation method, the obtained abdominal CT effective dose showed some variations. In general, the abdominal CT examination causes higher effective dose for females than for males. Subsequently, sex-specific effective dose calculation may be recommended particularly for abdominal CT examination.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eThis article is achieved by a single author\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eFunding Declaration \u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eDimitroukas CP, Metaxas VI, Efthymiou FO, Kalogeropoulou CP, Zampakis PE, Panayiotakis GS. Patient dose audit in common CT examinations. Radiation Physics and Chemistry. 2022;192:109924.\u003c/li\u003e\n\u003cli\u003eGolshan M, Ali B, Nima R, Reza M, Farzaneh J, Ali H. Evaluation of Cancer Risk Induced by Radiation Exposure from Normal Head CT Scans. Frontiers in Biomedical Technologies. 2023;10(3).\u003c/li\u003e\n\u003cli\u003eIAEA. Quality Assurance Programme for Computed Tomography: Diagnostic and Therapy Applications. Vienna: INTERNATIONAL ATOMIC ENERGY AGENCY; 2012.\u003c/li\u003e\n\u003cli\u003eAlmasri H, Inayyem W. Evaluation of Radiation Doses for Patients Undergoing Abdominopelvic Computed Tomography Examination in Palestine. Japanese Journal of Health Physics. 2021;56(2):75-9.\u003c/li\u003e\n\u003cli\u003eCostello JE, Cecava ND, Tucker JE, Bau JL. CT Radiation Dose: Current Controversies and Dose Reduction Strategies. American Journal of Roentgenology. 2013;201(6):1283-90.\u003c/li\u003e\n\u003cli\u003eSharma S, Kapadia A, Fu W, Abadi E, Segars WP, Samei E. A real-time Monte Carlo tool for individualized dose estimations in clinical CT. Physics in Medicine \u0026amp; Biology. 2019;64(21):215020.\u003c/li\u003e\n\u003cli\u003eUKHealthSecurityAgency. UKHSA-RCE-1: doses from computed tomography (CT) exams in the UK: 2019 review. UK: UK Health Security Agency; 2022.\u003c/li\u003e\n\u003cli\u003eEurostatStatisticsExplained. Healthcare resource statistics - technical resources and medical technology 2024 [updated 2024. Available from: https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Healthcare_resource_statistics_-_technical_resources_and_medical_technology\u0026amp;oldid=452031#Use_of_medical_technology.\u003c/li\u003e\n\u003cli\u003eRadiation UNSCotEoA. Sources, Effects and Risks of Ionizing Radiation, United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2020/2021 Report, Volume IV: United Nations; 2022.\u003c/li\u003e\n\u003cli\u003eTheIndustryRadiologicalProtectionCo-ordinationGroup(IRPCG). The Application of ALARP to Radiological Risk: A Nuclear Industry Good Practice Guide. 2012.\u003c/li\u003e\n\u003cli\u003eMasjedi H, Omidi R, Zamani H, Perota G, Zare MH. Radiation dose and risk of exposure-induced death associated with common computed tomography procedures in Yazd Province. European Journal of Radiology. 2020;126:108932.\u003c/li\u003e\n\u003cli\u003eNAS N. Health Risks from Exposure to Low Levels of Ionizing Radiation: BEIR VII \u0026ndash; Phase 2. Washington: National Academies Press; 2006.\u003c/li\u003e\n\u003cli\u003eRichardson DB, Leuraud K, Laurier D, Gillies M, Haylock R, Kelly-Reif K, et al. Cancer mortality after low dose exposure to ionising radiation in workers in France, the United Kingdom, and the United States (INWORKS): cohort study. Bmj. 2023;382:e074520.\u003c/li\u003e\n\u003cli\u003eCao CF, Ma KL, Shan H, Liu TF, Zhao SQ, Wan Y, et al. CT Scans and Cancer Risks: A Systematic Review and Dose-response Meta-analysis. BMC cancer. 2022;22(1):1238.\u003c/li\u003e\n\u003cli\u003eBagherzadeh S, MirDerikvand A, MohammadSharifi A. Evaluation of radiation dose and radiation-induced cancer risk associated with routine CT scan examinations. Radiation Physics and Chemistry. 2024;217:111521.\u003c/li\u003e\n\u003cli\u003eICRP. Managing Patient Dose in Multi-Detector Computed Tomography (MDCT). ICRP Publication 102. Ann ICRP. 2007;37(1).\u003c/li\u003e\n\u003cli\u003eElbakri IA, Kirkpatrick IDC. Dose-Length Product to Effective Dose Conversion Factors for Common Computed Tomography Examinations Based on Canadian Clinical Experience. Canadian Association of Radiologists Journal. 2013;64(1):15-7.\u003c/li\u003e\n\u003cli\u003eICRP. The 2007 Recommendations of the International Commission on Radiological Protection (Publication 103). Annals of the ICRP. 2007;37(2-4):1-332.\u003c/li\u003e\n\u003cli\u003eMcCollough CH, Chen GH, Kalender W, Leng S, Samei E, Taguchi K, et al. Achieving routine submillisievert CT scanning: report from the summit on management of radiation dose in CT. Radiology. 2012;264(2):567-80.\u003c/li\u003e\n\u003cli\u003eEuropeanCommission. European guidelines on quality criteria for computed tomography: Publications Office; 2000.\u003c/li\u003e\n\u003cli\u003eBrady SL, Mirro AE, Moore BM, Kaufman RA. How to Appropriately Calculate Effective Dose for CT Using Either Size-Specific Dose Estimates or Dose-Length Product. American Journal of Roentgenology. 2015;204(5):953-8.\u003c/li\u003e\n\u003cli\u003eMuhogora WE, Ahmed NA, Almosabihi A, Alsuwaidi JS, Beganovic A, Ciraj-Bjelac O, et al. Patient Doses in Radiographic Examinations in 12 Countries in Asia, Africa, and Eastern Europe: Initial Results from IAEA Projects. American Journal of Roentgenology. 2008;190(6):1453-61.\u003c/li\u003e\n\u003cli\u003eAbuzaid MM, Elshami W, Sulieman A, Bradley D. Cumulative radiation exposure, effective and organ dose estimation from multiple head CT scans in stroke patients. Radiation Physics and Chemistry. 2022;199:110306.\u003c/li\u003e\n\u003cli\u003eICRP. Diagnostic Reference Levels in Medical Imaging. ICRP Publication 135 Ann ICRP. 2017;46(1).\u003c/li\u003e\n\u003cli\u003eLee C, Kim KP, Long D, Fisher R, Tien C, Simon SL, et al. Organ doses for reference adult male and female undergoing computed tomography estimated by Monte Carlo simulations. Medical physics. 2011;38(3):1196-206.\u003c/li\u003e\n\u003cli\u003eLee C, Kim KP, Long DJ, Bolch WE. Organ doses for reference pediatric and adolescent patients undergoing computed tomography estimated by Monte Carlo simulation. Medical physics. 2012;39(4):2129-46.\u003c/li\u003e\n\u003cli\u003eEL Fahssi M, Semghouli S, Amaoui B, Jroundi L, Çaoui M. Patient radiation doses from adult CT examinations at the Souss Massa Regional Hospital. Radioprotection. 2024;59(1):13-8.\u003c/li\u003e\n\u003cli\u003eAbdul Karim MK, Hashim S, Sabarudin S, Bradley D, Ashiqin N. Evaluating organ dose and radiation risk of routine CT examinations in Johor Malaysia. 2016;45:567-73.\u003c/li\u003e\n\u003cli\u003eBrady SL, Mirro AE, Moore BM, Kaufman RA. How to Appropriately Calculate Effective Dose for CT Using Either Size-Specific Dose Estimates or Dose-Length Product. AJR American journal of roentgenology. 2015;204(5):953-8.\u003c/li\u003e\n\u003cli\u003eLee SK, Kim JS, Yoon SW, Kim JM. Development of CT Effective Dose Conversion Factors from Clinical CT Examinations in the Republic of Korea. Diagnostics (Basel). 2020;10(9).\u003c/li\u003e\n\u003cli\u003eSmith-Bindman R, Lipson J, Marcus R, Kim KP, Mahesh M, Gould R, et al. Radiation dose associated with common computed tomography examinations and the associated lifetime attributable risk of cancer. Arch Intern Med. 2009;169(22):2078-86.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTable (1) Presents the number of patients as well as their sex as collected from the four hospitals.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 81px;\"\u003e\n \u003cp\u003eSex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" style=\"width: 334px;\"\u003e\n \u003cp\u003eHospital\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" style=\"width: 84px;\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eHosp. 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eHosp. 2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eHosp. 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003eHosp. 4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 81px;\"\u003e\n \u003cp\u003eMale\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e41\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 81px;\"\u003e\n \u003cp\u003eFemale\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 81px;\"\u003e\n \u003cp\u003eTotal\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 84px;\"\u003e\n \u003cp\u003e73\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTable (2) Presents the dosimtric data (mean \u0026plusmn; standard deviation) for the seventy-three patients considered in this study.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"584\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 42px;\"\u003e\n \u003cp\u003eSex\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 90px;\"\u003e\n \u003cp\u003eParameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 90px;\"\u003e\n \u003cp\u003eHosp. 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 89px;\"\u003e\n \u003cp\u003eHosp. 2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 90px;\"\u003e\n \u003cp\u003eHosp. 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 95px;\"\u003e\n \u003cp\u003eHosp. 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 87px;\"\u003e\n \u003cp\u003eAll patients\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 42px;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 90px;\"\u003e\n \u003cp\u003emAs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e173.83 \u0026plusmn; 32.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e137.67 \u0026plusmn; 29.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e199.59 \u0026plusmn; 86.32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e166.00 \u0026plusmn; 68.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 87px;\"\u003e\n \u003cp\u003e179.00 \u0026plusmn; 72.02\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 90px;\"\u003e\n \u003cp\u003eCTDIvol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e13.27 \u0026plusmn; 2.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e6.13 \u0026plusmn; 1.32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e8.87 \u0026plusmn; 3.80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e7.45 \u0026plusmn; 3.03\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 87px;\"\u003e\n \u003cp\u003e7.45 \u0026plusmn; 3.03\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 90px;\"\u003e\n \u003cp\u003eDLP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e631.00 \u0026plusmn; 155.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e288.2 \u0026plusmn;\u003c/p\u003e\n \u003cp\u003e60.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e501.12 \u0026plusmn; 244.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e408.27 \u0026plusmn; 220.96\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 87px;\"\u003e\n \u003cp\u003e470.58 \u0026plusmn; 228.94\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"3\" style=\"width: 42px;\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 90px;\"\u003e\n \u003cp\u003emAs\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e195.25 \u0026plusmn; 53.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e158.71 \u0026plusmn; 38.76\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e288.64 \u0026plusmn; 79.19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e231.60 \u0026plusmn; 66.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 87px;\"\u003e\n \u003cp\u003e210.09 \u0026plusmn; 69.10\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 90px;\"\u003e\n \u003cp\u003eCTDIvol\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e14.91 \u0026plusmn; 4.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e7.08 \u0026plusmn; 1.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e10.20 \u0026plusmn; 3.51\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e10.36 \u0026plusmn; 3.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 87px;\"\u003e\n \u003cp\u003e10.16 \u0026plusmn; 3.73\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 90px;\"\u003e\n \u003cp\u003eDLP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e646.25 \u0026plusmn; 229.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 89px;\"\u003e\n \u003cp\u003e353.23 \u0026plusmn; 96.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 90px;\"\u003e\n \u003cp\u003e572.91\u0026plusmn; 216.66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 95px;\"\u003e\n \u003cp\u003e546.40 \u0026plusmn; 187.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 87px;\"\u003e\n \u003cp\u003e525.74 \u0026plusmn; 204.41\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eTable (3) Presents the calculated organ dose (mGy) for males and females participated in current study.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"605\" class=\"fr-table-selection-hover\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" style=\"width: 150px;\"\u003e\n \u003cp\u003eorgan\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 226px;\"\u003e\n \u003cp\u003eMale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" style=\"width: 229px;\"\u003e\n \u003cp\u003eFemale\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e(mean\u0026plusmn;sd)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003eRange\u003c/p\u003e\n \u003cp\u003e(min.\u0026ndash;max.)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e(mean\u0026plusmn;sd)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003eRange\u003c/p\u003e\n \u003cp\u003e(min.\u0026ndash;max.)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eBrain\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e0.02 \u0026plusmn; 0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.00 - 0.11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.03 \u0026plusmn; 0.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e0.00 - 0.09\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eSalivary gland\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e0.04 \u0026plusmn; 0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.01 - 0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.07 \u0026plusmn; 0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e0.01 - 0.19\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eThyroid\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e0.17 \u0026plusmn; 0.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.03 - 0.97\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.27 \u0026plusmn; 0.18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e0.04 - 0.70\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eBreast\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e9.11 \u0026plusmn; 8.83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e1.63 - 54.32\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e8.39 \u0026plusmn; 5.43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e1.29 - 22.76\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eLung\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e3.49 \u0026plusmn; 3.37\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.62 - 20.56\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e4.17 \u0026plusmn; 2.72\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e0.64 - 11.19\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eLiver\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e11.31 \u0026plusmn; 10.91\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e2.00 - 66.66\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e16.49 \u0026plusmn; 10.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e2.53 - 44.44\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eoesophagus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e2.63 \u0026plusmn; 2.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.46 - 15.26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e4.11 \u0026plusmn; 2.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e0.62 - 10.93\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eStomach\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e10.84 \u0026plusmn; 10.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e1.91 - 63.74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e16.76 \u0026plusmn; 10.88\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e2.57 - 45.14\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eColon\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e11.82 \u0026plusmn; 11.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e2.09 - 69.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e20.13 \u0026plusmn; 13.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e3.11 - 54.67\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eBladder\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e5.98 \u0026plusmn; 5.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e1.05 - 34.84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e9.34 \u0026plusmn; 6.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e1.42 - 24.94\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eTestes / Ovaries\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e1.24 \u0026plusmn; 1.19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.21 - 7.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e12.06 \u0026plusmn; 7.90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e1.83 - 32.10\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eBone marrow\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e3.85 \u0026plusmn; 3.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.67 - 22.18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e6.14 \u0026plusmn; 4.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e0.92 - 16.18\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eSkin\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e3.63 \u0026plusmn; 3.53\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.66 - 21.86\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e4.91 \u0026plusmn; 3.16\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e0.76 - 13.43\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eOral mucosa\u003csup\u003e*\u003c/sup\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e0.04 \u0026plusmn; 0.04\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.01 - 0.22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.10 \u0026plusmn; 0.06\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e0.01 - 0.26\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eHeart\u003csup\u003e*\u003c/sup\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e3.73 \u0026plusmn; 3.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.66 - 21.86\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e5.11 \u0026plusmn; 3.33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e0.78 - 13.68\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eThymus\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e0.41 \u0026plusmn; 0.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.07 - 2.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e0.59 \u0026plusmn; 0.39\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e0.09 - 1.53\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003ePancreas\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e9.09 \u0026plusmn; 8.74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e1.59 - 52.92\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e14.82 \u0026plusmn; 9.69\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e2.25 - 39.58\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eSpleen\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e11.48 \u0026plusmn; 11.10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e2.04 - 68.07\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e16.97 \u0026plusmn; 10.99\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e2.61 - 45.97\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eGallbladder\u003csup\u003e*\u003c/sup\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e9.84 \u0026plusmn; 9.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e1.72 - 57.35\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e14.55 \u0026plusmn; 9.52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e2.21 - 38.81\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eAdrenal gland\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e9.16 \u0026plusmn; 8.81\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e1.60 - 53.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e13.13 \u0026plusmn; 8.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e1.99 - 35.04\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eKidney\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e11.44 \u0026plusmn; 11.02\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e2.01 - 67.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e18.10 \u0026plusmn; 11.77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e2.77 - 48.66\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eSmall intestine\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e9.88 \u0026plusmn; 9.50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e1.73 - 57.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e16.58 \u0026plusmn; 10.79\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e2.53 - 44.50\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eProstate\u003csup\u003e*\u003c/sup\u003e/ Uterus\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e1.40 \u0026plusmn;1.34\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.24 - 8.01\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e9.56 \u0026plusmn; 6.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e1.44 - 25.32\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 150px;\"\u003e\n \u003cp\u003eMuscle\u003csup\u003e*\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 118px;\"\u003e\n \u003cp\u003e4.12 \u0026plusmn; 3.98\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 108px;\"\u003e\n \u003cp\u003e0.73 - 24.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 120px;\"\u003e\n \u003cp\u003e5.68 \u0026plusmn; 3.68\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 110px;\"\u003e\n \u003cp\u003e0.87 - 15.34\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"5\" style=\"width: 605px;\"\u003e\n \u003cp\u003e\u003cem\u003e\u003csup\u003e*\u003c/sup\u003e\u003c/em\u003e\u003cem\u003eIndicate other organs in effective dose calculation\u003c/em\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"CT abdomen, radiation risk, CT dosimentry, organ dose","lastPublishedDoi":"10.21203/rs.3.rs-7381034/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7381034/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eIntroduction:\u003c/h2\u003e\u003cp\u003eSince the introduction of computed tomography (CT), there has been a progressive concern about its associated radiation risk. This study aims to compare the radiation effective dose (ED) of abdominal CT examination calculated by two different methods.\u003c/p\u003e\u003ch2\u003eMaterial and Methods\u003c/h2\u003e\u003cp\u003eDosimetric data of abdominal CT examination was used to calculate ED for 73 adult patients; 41 males and 32 females. For each participant the ED was calculated three times. The first and second times were by the use of DLP to ED conversion factors (\u003cem\u003ek\u003c/em\u003e-coefficients) which are published by the European Commission (EC) and that specifically published for SOMATOM Definition SA / Siemens CT machine. The other method includes the calculation of ED based on organ dose, which are obtained by CTDI\u003csub\u003evol\u003c/sub\u003e to organ dose conversion factors.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eThe ED calculated by both machine specific DLP to ED conversion factor and organ dose method tend to be comparable 7.96 mSv and 8.05 mSv, respectively. A smaller ED was obtained by the use EC\u0026rsquo;s DLP to ED conversion factor, 7.42 mSv. However, these variations are statistically non-significant. For all calculation methods, ED was higher for female patients than for male patients.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e\u003cp\u003eThe abdominal CT ED estimated in this study was within the internationally recommended levels. However, sex-specific ED calculation may be recommended.\u003c/p\u003e","manuscriptTitle":"Estimation of Radiation Effective Dose from Abdominal CT Examination Using Two Different Methods","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-09 09:55:54","doi":"10.21203/rs.3.rs-7381034/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"7235a35b-59d4-44e2-83cc-6760521dfcb4","owner":[],"postedDate":"September 9th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-04T15:59:02+00:00","versionOfRecord":{"articleIdentity":"rs-7381034","link":"https://doi.org/10.1186/s43055-026-01755-7","journal":{"identity":"egyptian-journal-of-radiology-and-nuclear-medicine","isVorOnly":false,"title":"Egyptian Journal of Radiology and Nuclear Medicine"},"publishedOn":"2026-04-27 15:57:11","publishedOnDateReadable":"April 27th, 2026"},"versionCreatedAt":"2025-09-09 09:55:54","video":"","vorDoi":"10.1186/s43055-026-01755-7","vorDoiUrl":"https://doi.org/10.1186/s43055-026-01755-7","workflowStages":[]},"version":"v1","identity":"rs-7381034","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7381034","identity":"rs-7381034","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}