Radiological study of clavicle for age estimation

Abstract

The ossification process of medial clavicular epiphysis has been studied in the thesis submitted for age determination. The ossification stages have been retrospectively analyzed in 250 subjects of each sex falling in the age group of 12 to 30 years, as per protocol. Data was acquired by performing computed tomography (CT) chest of these patients on 16-slice Multi-detector CT scan machine using parameter---Kvp=120, mAs=150, Pitch factor=1.15, scan time=0.5sec and slice collimation=16x1.5. Data acquired was reconstructed in 2mm thick slices at bone window (450/1500) using kernel b60f (a filter suitable for viewing osseous structures). The ossification process was evaluated on the basis of five stages classification criterion defined by Schmeling et al.,(2004). The stage 1 observed to be completed by 17 years of age in both the sexes. The onset of stage 2 was found approximately one year advanced (at the age of 14years) in females as compared to males and also finished one year earlier in females (18 years of age) than males. The commencement of stage 3 was found at same age in both the sexes, but finished one year earlier (at 25 years) in females than males. The stage 4 was also first observed one year later (at 21 years) in males than females, but was finished one year earlier (at 29 years) in males. The stage 5 was also commenced one year earlier (at 25 years) in females as compares to males. No case of stage 5 could be observed before 25 years of age in either of the sex. Some technique specific parameters were also studied in addition to the above mentioned work so as to verify the effect of these parameters on the results and described as following; The ossification stages were studied in 100 subjects at different slice thickness ( 1mm,2mm, 3mm,5mm and 7mm) to find out the effect slice thickness on staging. The results were found to be identical with 1 and 2mm slice thickness, but the staging was found different in some cases with 3mm, 5mm and 7mm slice thickness.