206 H . Sekkat et al .: Radioprotection 2024 , 59 ( 3 ), 203 – 210
Table 2 . Regression coefficients and R 2 values for Deff and Dw variations across age groups in male , female and both genders . Male Female Both genders
|
Deff |
Dw |
Deff |
Dw |
Deff |
Dw |
R 2 value |
0.83 |
0.86 |
0.71 |
0.65 |
0.64 |
0.67 |
a value |
9.97008 |
10.25704 |
10.52196 |
11.02101 |
10.64694 |
10.33249 |
b value |
�0.05614 |
�0.06101 |
�0.06665 |
�0.04867 |
�0.04463 |
�0.06026 |
c value |
2.58276 |
2.87073 |
2.68613 |
2.00863 |
2.1848 |
2.77693 |
d value |
0.92441 |
0.81714 |
�0.54684 |
�1.22631 |
�0.20106 |
0.53055 |
Fig . 2 . Variations in ( Deff ) and ( Dw ) across age groups in all patients ( males and females ).
ICRU report 74 , which delineates the dimensions of mathematical phantoms representing hermaphrodite humans across five distinct age groups . The visual representation in Figure 7 highlights that our findings , when juxtaposed with the corresponding ICRU data for individuals of equivalent age , consistently exhibit slightly lower values . These variations range from 0.14 to 0.73 cm , highlighting a discernible dimension discrepancy between our study and the established ICRU reference .
4 Discussion
Prior research has investigated the relationship between age and specific patient size metrics , primarily focusing on effective diameter ( Frush et al ., 2003 ; Wang et al ., 2012 ; Anam et al ., 2017 ). Notably , Deff , while commonly used , is less accurate than Dw , which incorporates both physical dimensions and attenuation characteristics of the scanned body . However , there remains a notable gap in the literature regarding the correlation between head size , particularly Dw , and age in pediatric patients . This study addresses this gap , emphasizing the significance of understanding this relationship , particularly for size-specific dose estimates in pediatric head CT scans .
As anticipated , both male and female children exhibit an increase in head diameter with age , with rapid growth observed from birth to 3 yr , followed by a more gradual increase thereafter . Consistently , Dw values indicate that males have greater values than females , suggesting higher bone and brain