Interobserver reliability in quantitative MRI assessment of temporomandibular joint disk status

Objective. The purpose of this study was to investigate interobserver reliability of a new technique for quantification of magnetic resonance images of temporomandibular joint disk status. Study design. Sixty magnetic resonance images of adolescent temporomandibular joints were randomly drawn for analysis. Four experienced observers traced the articular disk and osseous structures on sagittal magnetic resonance slice images. Quantitative measurements of disk length and disk displacement were recorded for each slice of 57 joints traced by each observer through use of a new quantification technique. Intraclass correlation coefficients were computed to assess interobserver agreement in the tracing of joint structures. Results. The calculated intraclass correlation coefficient was 0.681 for disk length and 0.830 for disk displacement. In addition, the mean variability among observers was 1.041 mm for measurement of disk length and 0.972 mm for measurement of disk displacement. Conclusions. Interobserver agreement is high when the new quantification technique is used to interpret magnetic resonance images.