Chulalongkorn Medical Journal


Background : CT is the standard equipment for assessing a variety of disorderin children. More than half of pediatric CT examinations at KingChulalongkorn Memorial Hospital (KCMH) are related to the brain.Nevertheless, there is no available data of pediatric radiationdose from CT brain at KCMH.Objective : To investigate the radiation dose when CT brain is performedand compare with the previously published dose referencelevels (DRLs) in order to minimize or eliminate the amount ofunnecessary radiation exposure.Design : Retrospective descriptive data.Setting : Department of Radiology, Faculty of Medicine, ChulalongkornUniversityMaterials and Methods : Of the total 349 examinations in 2009, volume CT dose index(CTDIvol), dose length product (DLP) and image noise werecollected. Effective dose was accomplished by multiply DLPwith age-specific conversion coefficients. Third quartile valuesof these parameters were compared with the German and UKDRL.Results : CTDIvol were lower than DRL from the UK and German in mostpediatric age groups. Only 4 patients aged below 5 years old(2.3%) received higher CTDIvol. Two out of four age groupsshowed greater DLP than DRL from the UK but still lower thanthe German value. Approximately, 21% (75/349) performedscanning more than twice in the same study. Effective dose inpatients younger than 10 years demonstrated greater valuewhich reflects overall higher DLP. Image noise displayed nodifference in each age group and comparable with previousstudies.Conclusion : Most of our radiation dose parameters are within the appropriaterange. However, there is a little problem with rescanning andover scan length. Stringent to CT protocol and proper prescanningevaluation may be a good solution.


Faculty of Medicine, Chulalongkorn University

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