Agreement on grading of normal clivus using magnetic resonance imaging among radiologists

Abstract

Purpose: The present study was aimed to evaluate the agreement on grading normal clivus on MRI among radiologists. Methods: A retrospective study included patients who underwent MRI brain during January 1, 2015 to October 31, 2019. Two hundred forty-four patients who had no marrow pathology on MRI were included and divided into 8 age groups by decades. Three radiologists independently reviewed the signal intensity of clivus in mid sagittal T1-weighted image. The signal intensity was classified into three grades (Grade I-III). Fleiss’ kappa coefficients (k) were calculated to assess interrater agreement. Results: Of 244 patients, there were 123 (50.4%) males and 121 (49.6%) females. Age ranged from 1 to 79 years old. Clivus Grade II was more frequently reported (> 50%) by radiologists. The agreement (kappa) among all three radiologists on evaluation of clivus irrespective of the grading equals to 0.67 (95%CI: 0.60–0.74). In stratified analyses by the grade of clivus, the kappa values for Grade I to III and were 0.73, 0.62, and 0.69 respectively. Conclusion: Interrater agreement of MRI evaluation of normal clivus among radiologists was good. The visual grading criteria to classify the clivus is sufficient to distinguish the marrow maturation. However, the consensus reading should be made whenever normal clivus Grade II is read.

Keywords

• Clivus
• Marrow conversion
• MRI
• Agreement
• Kappa statistic