[Forensic Age Determination Using MRI Scans of the Ankle: Applying Two Classifications to Assess Ossification]

Area of Science:

• Forensic medicine
• Radiology
• Orthopedics

Background:

• Forensic age determination is crucial for legal proceedings, often relying on skeletal development assessments.
• Current methods, like those from the Study Group on Forensic Age Diagnostics (AGFAD), utilize ionizing radiation imaging.
• Magnetic Resonance Imaging (MRI) classifications for knee joint fusion have been proposed to determine age limits.

Purpose of the Study:

• To evaluate the applicability of existing MRI classifications (Vieth et al. and Ottow et al.) for the knee joint to ankle MRI for forensic age estimation.
• To determine if these classifications can reliably assess ossification stages and corresponding chronological ages in the ankle.
• To analyze gender-specific differences and observer variability in ankle MRI age assessment.

Main Methods:

• Retrospective analysis of ankle MRI scans from 333 patients (aged 10-28 years).
• Application of T1-weighted TSE and T2-weighted fat-suppressed sequences using Vieth et al. and Ottow et al. classifications.
• Determination of ossification stages, assignment of chronological ages, gender-specific analysis, and assessment of intra- and inter-observer variability (Cohen's kappa).

Main Results:

• Both Vieth et al. and Ottow et al. classifications successfully determined the completion of the 14th year of life in both sexes.
• The Vieth et al. classification also identified the completion of the 18th year of life in male patients.
• High intra-observer (κ > 0.87) and good inter-observer (κ > 0.72) variability confirmed reliability.

Conclusions:

• MRI classifications developed for the knee joint are applicable to the ankle joint for forensic age determination.
• This radiation-free method offers a valuable alternative or supplementary tool for establishing legal age limits.
• The findings support the use of ankle MRI as a reliable component of forensic age assessment protocols.