Interobserver reliability in quantitative MRI assessment of temporomandibular joint disk status

Objective. The purpose of this study was to investigate interobserver relia bility of a new technique for quantification of magnetic resonance images o f temporomandibular joint disk status. Study design. Sixty magnetic resonance images of adolescent temporomandibul ar joints were randomly drawn for analysis. Four experienced observers trac ed the articular disk and osseous structures on sagittal magnetic resonance slice images. Quantitative measurements of disk length and disk displaceme nt were recorded for each slice of 57 joints traced by each observer throug h use of a new quantification technique. Intraclass correlation coefficient s were computed to assess interobserver agreement in the tracing of joint s tructures. Results. The calculated intraclass correlation coefficient was 0.681 for di sk length and 0.830 for disk displacement. In addition, the mean variabilit y 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 te chnique is used to interpret magnetic resonance images.