Age-Dependent Changes in Effective Dose in Pediatric Brain CT: Comparisons of Estimation Methods

The effective dose (ED) in computed tomography (CT) may be calculated by multiplying the dose–length product (DLP) by a conversion factor. As children grow, automatic exposure control increases the DLP, while the conversion factor decreases; these two changes affect the ED in opposite ways. The aim...

Full description

Bibliographic Details
Main Authors: Yusuke Inoue, Masahiro Mori, Hiroyasu Itoh, Kohei Mitsui, Hiroki Miyatake, Takuro Yamane, Hirofumi Hata
Format: Article
Language:English
Published: MDPI AG 2023-12-01
Series:Tomography
Subjects:
Online Access:https://www.mdpi.com/2379-139X/10/1/2
_version_ 1827371123956776960
author Yusuke Inoue
Masahiro Mori
Hiroyasu Itoh
Kohei Mitsui
Hiroki Miyatake
Takuro Yamane
Hirofumi Hata
author_facet Yusuke Inoue
Masahiro Mori
Hiroyasu Itoh
Kohei Mitsui
Hiroki Miyatake
Takuro Yamane
Hirofumi Hata
author_sort Yusuke Inoue
collection DOAJ
description The effective dose (ED) in computed tomography (CT) may be calculated by multiplying the dose–length product (DLP) by a conversion factor. As children grow, automatic exposure control increases the DLP, while the conversion factor decreases; these two changes affect the ED in opposite ways. The aim of this study was to investigate the methods of ED estimation according to age in pediatric brain CT. We retrospectively analyzed 980 brain CT scans performed for various clinical indications in children. The conversion factor at each age, in integer years, was determined based on the values at 0, 1, 5, and 10 years provided by the International Commission on Radiological Protection (ICRP), using a curve (curve method) or lines (linear method). In the simple method, the ED was estimated using the ICRP conversion factor for the closest age. We also analyzed the ED estimated by a radiation dose management system. Although the median DLP at each age increased with age, the median ED estimated by the curve method was highest at 0 years, decreased with age, and then plateaued at 9 years. The linear method yielded mildly different results, especially at 2 and 3 years. The ED estimated by the simple method or the radiation dose management system showed inconsistent, up-and-down changes with age. In conclusion, the ED in pediatric brain CT decreases with age despite increased DLP. Determination of the conversion factor at each age using a curve is expected to contribute to estimating the ED in pediatric CT according to age.
first_indexed 2024-03-08T10:34:37Z
format Article
id doaj.art-a110674776bf4fac997b2c3817b1c8dd
institution Directory Open Access Journal
issn 2379-1381
2379-139X
language English
last_indexed 2024-03-08T10:34:37Z
publishDate 2023-12-01
publisher MDPI AG
record_format Article
series Tomography
spelling doaj.art-a110674776bf4fac997b2c3817b1c8dd2024-01-26T18:40:16ZengMDPI AGTomography2379-13812379-139X2023-12-01101142410.3390/tomography10010002Age-Dependent Changes in Effective Dose in Pediatric Brain CT: Comparisons of Estimation MethodsYusuke Inoue0Masahiro Mori1Hiroyasu Itoh2Kohei Mitsui3Hiroki Miyatake4Takuro Yamane5Hirofumi Hata6Department of Diagnostic Radiology, Kitasato University School of Medicine, Sagamihara 252-0374, JapanDepartment of Diagnostic Radiology, Kitasato University School of Medicine, Sagamihara 252-0374, JapanDepartment of Radiology, Kitasato University Hospital, Sagamihara 252-0375, JapanDepartment of Diagnostic Radiology, Kitasato University School of Medicine, Sagamihara 252-0374, JapanDepartment of Radiology, Kitasato University Hospital, Sagamihara 252-0375, JapanDepartment of Diagnostic Radiology, Kitasato University School of Medicine, Sagamihara 252-0374, JapanDepartment of Radiology, Kitasato University Hospital, Sagamihara 252-0375, JapanThe effective dose (ED) in computed tomography (CT) may be calculated by multiplying the dose–length product (DLP) by a conversion factor. As children grow, automatic exposure control increases the DLP, while the conversion factor decreases; these two changes affect the ED in opposite ways. The aim of this study was to investigate the methods of ED estimation according to age in pediatric brain CT. We retrospectively analyzed 980 brain CT scans performed for various clinical indications in children. The conversion factor at each age, in integer years, was determined based on the values at 0, 1, 5, and 10 years provided by the International Commission on Radiological Protection (ICRP), using a curve (curve method) or lines (linear method). In the simple method, the ED was estimated using the ICRP conversion factor for the closest age. We also analyzed the ED estimated by a radiation dose management system. Although the median DLP at each age increased with age, the median ED estimated by the curve method was highest at 0 years, decreased with age, and then plateaued at 9 years. The linear method yielded mildly different results, especially at 2 and 3 years. The ED estimated by the simple method or the radiation dose management system showed inconsistent, up-and-down changes with age. In conclusion, the ED in pediatric brain CT decreases with age despite increased DLP. Determination of the conversion factor at each age using a curve is expected to contribute to estimating the ED in pediatric CT according to age.https://www.mdpi.com/2379-139X/10/1/2agebraincomputed tomographyeffective dosepediatricsradiation dose
spellingShingle Yusuke Inoue
Masahiro Mori
Hiroyasu Itoh
Kohei Mitsui
Hiroki Miyatake
Takuro Yamane
Hirofumi Hata
Age-Dependent Changes in Effective Dose in Pediatric Brain CT: Comparisons of Estimation Methods
Tomography
age
brain
computed tomography
effective dose
pediatrics
radiation dose
title Age-Dependent Changes in Effective Dose in Pediatric Brain CT: Comparisons of Estimation Methods
title_full Age-Dependent Changes in Effective Dose in Pediatric Brain CT: Comparisons of Estimation Methods
title_fullStr Age-Dependent Changes in Effective Dose in Pediatric Brain CT: Comparisons of Estimation Methods
title_full_unstemmed Age-Dependent Changes in Effective Dose in Pediatric Brain CT: Comparisons of Estimation Methods
title_short Age-Dependent Changes in Effective Dose in Pediatric Brain CT: Comparisons of Estimation Methods
title_sort age dependent changes in effective dose in pediatric brain ct comparisons of estimation methods
topic age
brain
computed tomography
effective dose
pediatrics
radiation dose
url https://www.mdpi.com/2379-139X/10/1/2
work_keys_str_mv AT yusukeinoue agedependentchangesineffectivedoseinpediatricbrainctcomparisonsofestimationmethods
AT masahiromori agedependentchangesineffectivedoseinpediatricbrainctcomparisonsofestimationmethods
AT hiroyasuitoh agedependentchangesineffectivedoseinpediatricbrainctcomparisonsofestimationmethods
AT koheimitsui agedependentchangesineffectivedoseinpediatricbrainctcomparisonsofestimationmethods
AT hirokimiyatake agedependentchangesineffectivedoseinpediatricbrainctcomparisonsofestimationmethods
AT takuroyamane agedependentchangesineffectivedoseinpediatricbrainctcomparisonsofestimationmethods
AT hirofumihata agedependentchangesineffectivedoseinpediatricbrainctcomparisonsofestimationmethods