H . Sekkat et al .: Radioprotection 2024 , 59 ( 3 ), 203 – 210 205
Fig . 1 . Lateral and anterior-posterior measurements using RadiAnt Dicom Viewer .
Therefore , the Dw of a patient can be calculated using the following equation : sffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
D w ¼ 2 ⌊ 1 1000 CTðx ; yÞ Á A ROI
ROIþ1 I : ð4bÞ p
( AAPM , 2014 )
We performed a comprehensive analysis to investigate the correlation between patient age and the values of effective diameter and water-equivalent diameter . This analytical examination was conducted utilizing a regression approach , specifically guided by ( Eq . ( 5 )) outlined in the American Association of Physicists in Medicine report number 204 ( AAPM , 2011 ). This regression analysis aimed to elucidate the relationships between patient age and the determined values of Deff and Dw , providing insights into how these parameters vary with the age of the pediatric population under consideration . y ¼ a þ bx 1 : 5 þ cx 0 ; 5 þ de �x : ð5Þ
The parameters a , b , c , and d in the equation were determined through a non-linear regression analysis conducted using OriginPro Version 22 . This process involved the formulation of a customized non-linear regression equation within the software , tailored to fit our specific model . To expound on the methodology employed by the software for parameter determination , OriginPro utilizes an iterative optimization process , such as the Levenberg-Marquardt algorithm . Subsequently , the R-squared value , indicative of the goodness of fit , was computed within the same software .
3 Results
The findings of the current study highlight the relationship between Deff and Dw across different age groups and sexes for pediatric patients aged 0 to 13 yr ( Tab . 2 ). Notably , Dw consistently surpasses Deff for patients of the same age , with Deff values ranging from 9.02 to 18.77 cm and Dw values spanning from 9.83 to 20.16 cm for male patients . Similarly , for female patients , Deff values range from 8.77 to 17.41 cm , while Dw values vary from 8.92 to 18.37 cm . The data underlines a consistent increase in head diameter throughout the selected age range , with a notable rapid expansion observed during infancy ( 0 – 3 yr ) followed by a relatively stable growth rate between ages 3 and 14 yr ( Fig . 2 ). Additionally , our analysis reveals gender-specific variations , particularly regarding Deff values , where males consistently exhibit higher values compared to females from ages 4 to 14 yr ( Fig . 3 ). However , Dw values consistently show males with higher values across all age groups , except around the age of 3 yr , where Dw values for males become roughly equivalent to those of females ( Fig . 4 ). These findings highlight the dynamic nature of cranial development during early life stages and the importance of sex-specific considerations in pediatric radiology .
Figure 5 offers a detailed comparative analysis between the outcomes of our current study and the data outlined in the