Estimation of adaptive computed tomography dose index based on body weight in pediatric patients.
OBJECTIVE
The aim of this study was to create an adaptive computed tomography dose index (by volume) (CTDI vol) for pediatric patients that would be fitted to a patient's particular body weight and to compare the adaptive CTDI vol with the CTDI vol displayed on the screen of the CT console.


METHODS
CT images of 60 children whose body weights were known were available for calculating the total amount of modified CT numbers as an attenuation area. The attenuation area values of four differentsized acryl phantoms were also calculated. The dose measurements of all four phantoms were carried out. We combined the results of the abdominal CT and phantom experiments. The weight-based complementary ratio for adaptive CTDI vol was calculated, and the result was applied to an example of pediatric abdominal CT protocol.


RESULTS
The adaptive CTDI vol was always larger than the displayed CTDI vol with both small and large fields of view (FOV). The adaptive CTDI vol was 2.2 times larger than the displayed CTDI vol in the maximum value with the large FOV and 1.2 times larger with the small FOV.


CONCLUSIONS
We radiologists must be the child's advocate and protect children from the deleterious effects of any of our technologies, including a lower indication of CTDI vol on the screen of a CT console.
Miyazaki
Osamu
O
Department of Radiology, National Center for Child Health and Development, 2-10-1 Okura, Tokyo, 157-8535, Japan. osamu-m@rc4.so-net.ne.jp
Horiuchi
Tetsuya
T
Masaki
Hidekazu
H
Nosaka
Shunsuke
S
Miyasaka
Mikiko
M
Tsutsumi
Yoshiyuki
Y
Okada
Yoshiyuki
Y
Kitamura
Masayuki
M
D000293:Adolescent; D001835:Body Weight / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011860:Radiography, Abdominal / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*