Evaluation of knee ossification on 1.5 T magnetic resonance images using the method of Vieth et al.

Magnetic resonance imaging (MRI) is a non-invasive method with the absence of ionizing radiation exposure and is therefore, preferable in studies for forensic age estimation. The purpose of this study was to investigate the degree of ossification of the knee in a Turkish population following the Vieth et al. method. We scanned 709 Turkish patients in the age bracket 12–27 years utilizing a T1-weighted (T1W) turbo spin echo sequence (TSE) and a T2‑W TSE sequence with fat suppression by spectral presaturation with inversion recovery. Minimum, maximum, mean ± standard deviation and median values were defined. Intraobserver and interobserver correlations were determined (Cohen’s kappa). The statistical relevance of sex-related differences was analyzed (Student’s t-test, Mann-Whitney U-test, p < 0.05, exact test, two-sided). The kappa statistics were relatively high, indicating very good agreement for interobserver and intraobserver evaluations. Comparison of male and female data revealed significant between-gender differences for most stages (p < 0.05). The earliest mean ages at which ossification of stages 4, 5 and 6 were evident in the distal femoral epiphysis were 14.84, 15.81, and 20.76 years in males and 13.77, 14.77, and 20.45 years in females, respectively. Proximal tibial epiphysis of stages 4, 5, and 6 ossification was first noted at ages 13.57, 15.59, and 18.91 years in males and 13.29, 14.38, and 16.87 years in females, respectively. In the distal femoral epiphysis, stage 6 was found at 20 years of age for both genders and it can be employed to differentiate above and below the majority age cut-off.