Chulalongkorn Medical Journal


Background : CT is a standard imaging tool for assessing a variety ofpediatric disorders. However, a major drawback of these scansis the use of ionizing radiation which potentially increasesradiation-related malignancy risk. There has been no availabledata of pediatric radiation dose from chest and abdomen CT atKCMH.Objective : To assess radiation dose parameters and image quality of ourpediatric multi-slice chest and abdomen CT examinations, andcompare them to the diagnostic reference levels (DRLs) in orderto minimize or eliminate the amount of unnecessary radiationexposure.Design : Retrospective descriptive data.Setting : Department of Radiology, Faculty of Medicine, ChulalongkornUniversity.Materials and Methods : Of the total 49 examinations of chest CT and 25 examinations ofabdomen CT during Jan 2010 - June 2010, volume CT doseindex (CTDIvol), dose length product (DLP) and image noiseswere collected. Effective dose was accomplished by multiplyadjusted DLP with region- and age-specific conversioncoefficients. Third quartile values of CTDIvol and DLP werecompared to the DRLs.Results : None of the patients aged below 5 years received CTDIvol andDLP greater than those of the DRLs in chest and abdomen CTexaminations, while, a significant number of the patients agedolder than 5 years did. Thirteen out of 49 patients (27%) receivedCTDIvol and DLP greater than those of the DRLs from chest CT,8 out of 25 patients (32%) received CTDIvol greater than that ofthe DRLs from whole abdomen CT and almost all of them werenot performed following the department protocol. Image quality(image noise and image quality score) seemed to be greateramong patients aged above 5 years in both protocols.Conclusion : Our radiation dose parameters were within the DRLs range inpatients aged below 5 years but not in those above 5 years.Being stringent to CT protocol seems to be a good solution.The percentage of the studies not done following the protocolshould be solved and monitored.


Faculty of Medicine, Chulalongkorn University

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