RELIABILITY OF A MODIFIED GRADING SCHEME FOR MRI ASSESSMENT OF THORACIC INTERVERTEBRAL DISCS

Abstract

The study aimed to investigate the variability in interpreting magnetic resonance imaging (MRI) films for thoracic disc degeneration, using a 5-point MRI disc grading scale and a modified 3-point scale. Forty-six T2-weighted sagittal thoracic MRI films, comprising 18 males and 28 females, aged 7 to 73 years, (mean age =41±16.3 years), were randomly selected from 318 archived cases. Nuclear and anular degeneration, end-plate lesions and osteophytes were graded on the first 30 cases using a modified 3-point grading scale. The next 30 cases were evaluated using the 5-point grading scale. Repeat evaluations for both scales were conducted after a three- to six-month interval. The intra-rater kappa coefficient was higher using the 3-point scale (0.71 to 0.87, p < 0.001) compared to the 5-point scale (0.57 to 0.78, p < 0.001) for the end-plate–disc–end-plate components. The lowest intra-rater reliability was for osteophytes and the highest was for the nucleus. The intra-rater reliability was generally higher in the upper thoracic region compared to the mid and lower thoracic regions.