Forensic age estimation from the clavicle using 1.0T MRI--preliminary results

Objectives As forensic age estimations in the living are performed without medical indication, there is a need for the development of non-ionizing methods. This study investigates the use of 1.0 T MRI to visualize the ossification status of the medial end of the clavicle. Material and methods T2 weighted 3D images were collected from a 1.0 T MR system. We prospectively scanned 102 subjects, 47 autopsy cases and 55 living volunteers (12–33 years). Images were scored in blind trials by three observers using a 4-stage system. Observers differed by level of training and radiological expertise. Results Motion artefacts reduced image resolution in living subjects. However, mean age at stage 4 was significantly different from mean age at stage 2 and 3. The minimum age at stage 4 was 19.8 years. Inter-observer agreement was moderate for autopsy cases and slight for living subjects. By contrasting subjects of “incomplete fusion” (≤ stage 3 on both sides) against “fused” (at least one stage 4), agreement rate rose to moderate ( K = 0.414) for living subjects. Despite the low agreement rate, no subject younger than 18 years was assessed as having “fused” clavicles. Conclusion At lower image resolution, a 2-stage system increases agreements rates among observers. To further increase accuracy, clavicle staging needs to be performed by trained observers. If available, a 1.0 T MR system may be used for age estimation in the living. However, further studies are needed to ensure that the ability to discriminate adults from minors, i.e. 18 years, is maintained.