CT doses in children: a multicentre study

Abstract

We evaluated examination protocols used for common CT procedures of paediatric patients at different hospitals in Belgium in order to determine whether adjustments related to patient size are made in scanning parameters, and to compare patient doses with proposed reference levels. Three paediatric hospitals and one non-paediatric hospital participated in the study. Weighted CT dose-index (CTDI(w)), dose-length product (DLP) and effective dose (E) were evaluated for three patient ages (1 year, 5 years and 10 years) and three common procedures (brain, thorax and abdomen). CTDI(w) and DLP values higher than the reference levels were found for all types of evaluated examination. E ranged from 0.4 mSv to 2.3 mSv, 1.1 mSv to 6.6 mSv, and 2.3 mSv to 19.9 mSv for brain, thorax and abdomen examinations, respectively. All centres but one adapted their protocols as a function of patient size. However, no common trend in the selection of protocols was observed. Some centres divided the whole range of patient size into only two/three groups by age, while others classified the patients into six groups by weight. It was also observed that some centres used the same mAs for the total range of patient sizes and decreased the pitch factor for small children, which resulted in higher doses. This indicates the importance of careful selection of technical scan parameters. If CT parameters used for paediatric patients are not adjusted on the basis of examination type, age and/or size of the child, then some patients will be exposed to an unnecessarily high radiation dose during CT examinations.

Pediatricians’ awareness of diagnostic medical radiation effects and doses; are the latest efforts paying off?

“…There was a wide variability of selected imaging parameters and the type of CT equipment used (i.e., single or 4 to 64 multidetector), which results in different patient doses. For this reason, we used the mean values of the doses reported in the literature to establish reference doses for pediatric CT exams (13,(15)(16)(17) (Table 3). …”

Exames radiológicos na gestação

“…Em exames de TC do tórax, abdome, pelve e coluna lombar a dose de radiação absorvida pode ser reduzida diminuindo o campo de visão, a tensão (kV) e o produto da corrente pelo tempo de exposição (mAs) ao mínimo necessário para o diagnóstico, diminuindo o número de cortes e o intervalo entre estes (32)(33)(34)(35) . Em equipamentos helicoidais, utilizar "pitch" maior (igual ou superior a dois) oferece sensível redução da dose de radiação (36)(37)(38) . Mais recentemente, têm sido utilizados tomógrafos com múltiplas fileiras de detectores ("multislice"), o que tem proporcionado vantagens indiscutíveis, principalmente relacionadas à sua rapidez e definição em estudos abdominais e angiográficos (angio-TC).…”

Meta-Analysis of Cranial CT Scans in Children

“…Many medical centers in the USA and Europe do not make adequate efforts to minimize pediatric exposures in general use CT scanners [15, 19]. With increased availability and new indications, CT scan use in children has not diminished in recent years; indeed, it is rising [18,20,21,22].…”