Purpose: To assess the frequency, appropriateness, and radiation doses associated with multiphase computed tomography (CT) protocols for routine chest and abdomen–pelvis examinations in 18 countries. Materials and Methods: In collaboration with the International Atomic Energy Agency, multi-institutional data on clinical indications, number of scan phases, scan parameters, and radiation dose descriptors (CT dose–index volume; dose–length product [DLP]) were collected for routine chest (n = 1706 patients) and abdomen–pelvis (n = 426 patients) CT from 18 institutions in Asia, Africa, and Europe. Two radiologists scored the need for each phase based on clinical indications (1 = not indicated, 2 = probably indicated, 3 = indicated). We surveyed 11 institutions for their practice regarding single-phase and multiphase CT examinations. Data were analyzed with the Student t test. Results: Most institutions use multiphase protocols for routine chest (10/18 institutions) and routine abdomen–pelvis (10/11 institutions that supplied data for abdomen–pelvis) CT examinations. Most institutions (10/11) do not modify scan parameters between different scan phases. Respective total DLP for 1-, 2-, and 3-phase routine chest CT was 272, 518, and 820 mGy·cm, respectively. Corresponding values for 1- to 5-phase routine abdomen–pelvis CT were 400, 726, 1218, 1214, and 1458 mGy cm, respectively. For multiphase CT protocols, there were no differences in scan parameters and radiation doses between different phases for either chest or abdomen–pelvis CT ( P = 0.40-0.99). Multiphase CT examinations were unnecessary in 100% of routine chest CT and in 63% of routine abdomen–pelvis CT examinations. Conclusions: Multiphase scan protocols for the routine chest and abdomen–pelvis CT examinations are unnecessary, and their use increases radiation dose.

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BACKGROUND: Various researchers who carried out national and international surveys have reported wide variations in patient dose arising from specific X-ray examinations. Thus, assessment of radiation dose is an essential part in the optimization process. The aim of this study was to compare the entrance surface doses delivered to pediatric patients undergoing digital and computed radiography X-ray examination.MATERIAL AND METHODS: A cross-sectional study was conducted on 389 pediatric X-ray projections less than 15 years of age on eight X-ray machines in Addis Ababa in February 2009 E.C. The tube output of the X-ray machines in air was measured using RaySafe XI dosimeters. Then, entrance surface dose was estimated for common x-ray examinations like chest, skull, extremities and pelvis using established relation between X-ray tube output and radiographic parameters. These data were analyzed statistically using computer (Excel and SPSS method).RESULT: The third quartile estimated ESDs in mGy for both computed and digital radiography examinations of chest (AP) for age (0-1 year) were 0.24 and 0.15, (1-5 year) 0.3and 0.16. For the age group (5-10 year), it was 1.97 and 0.26 and for the(10-15 year)group, 0.56 and 0.18 respectively.These values were higher than those of the United Nations Scientific Committee’s on the Effects of Atomic Radiation’s established dose reference levels(in mGy for age (0-1 year) 0.02, (1-5 year) 0.03, (5-10 year) 0.04, and (10-15 year) 0.05 respectively).CONCLUSION: The wider dose variation between computed and digital radiography shows that there is a pressing need to minimize the detriment caused by unnecessary computed radiography.

Background: Medical x-ray exposures have the largest man made source of population exposure to ionizing radiation in different countries. Recent developments in medical imaging have led to rapid increases in a number of high dose xray examinations performed with significant consequences for individual patient doses and for collective dose to the population as a whole. It is therefore important in each country to make regular assessments of the magnitude of these large doses. Objectives: To calculate collective dose of the population as a result of radiation dose from diagnostic x-rays, thereby to estimate the annual incidence of cancer which would be reduced by the use of rare earth intensifying screen. Methods: Data on the number of diagnostic procedures using x-ray examination in year 2007 in nine governmental hospitals, excluding military hospitals, by body site were collected in Addis Ababa. The number of examinations of specific body site was multiplied by the average effective dose per examination to get the collective dose over the population. Based on International Commission on Radiological Protection (ICRP) the fatality risk of fatal cancers (5% per Sv) was estimated. Results: In this study, the annual collective dose over the population is 31.21manSv (0.0.42mSv per person). Based on ICRP fatality risk of 500 fatal cancers per 10,000 man-sieverts (5% per Sv), estimation of incidence of fatal cancers cases in year 2007 was 2 cases half of which can be reduced by adoption of rare earth screens. Conclusion: Although the use of ionizing radiation for diagnostic medical procedures is an acceptable part of modern medicine, there is also the potential for inappropriate use and unnecessary radiation dose to the patient, so the request of radiography must be justified. It is estimated that the adoption of rare earth screen technology might reduce the annual incidence of cancer which would be fatal after an average latency period of 18.4 years by half, hence this research recommended adopting rare earth screen technology in Ethiopia. [Ethiop.

Objective: To investigate the practice and attitudes of Medical radiologic technologists (MRTs')/radiographers on the use of Gonad shielding (GS)in pediatric radiological imaging. Methods:A questionnaire regarding MRTs' attitudes and on the use of Gonad shielding was developed based on relevant literatures and distributed to MRTs/ radiographers working in general radiography at Black Lion and St. Paul hospitals in a study period from June to August 2014. Descriptive (percentage of frequency) study was used to analyze the responses of the multiple choices. A separate questionnaire was prepared to evaluate the practice of GS in these two hospitals. Results:The radiographers had shown a positive attitude towards using GS, however none of them used it in daily practice for a various reason such as (GS may obscure region of interest 11.1%, uncooperative patient 16.7%, too busy 13.9%, GS not available 27.8% and no appropriate size GS 27.8%). The investigators had also reviewed 94 abdominal-pelvic radiographs and none was taken with application of GS. Conclusion:Although the radiographers had a positive attitude, none of them had applied GS while taking plain radiographs and/or CT scan in and around the gonads. Updates on their knowledge on gonadal shielding and enforcing every medical imaging technologist to comply with hospital protocols are recommended.