Application of the Kappa Statistic in CT Diagnosis of Lumbar Disk Herniation Through Profile-outlined Method and Conventional Reading

Objective To study the concordance of CT diagnosis for patients suspected of lumbar disk herniation through profile-outlined method and conventional reading by using Kappa statistic.Materials and Methods There were 432 L3-S1 disc of 144 cases of low back pain patients which doctor A had diagnosed. Two radiologists(doctor A and doctor B) used profile-outlining method to rediagnose and compared the results of conventional diagnosis. After 6 weeks doctor A rediagnose by using profile-outlining method. The Kappa statistics was employed to assess the concordance of each radiologists's diagnosis through the same method.Results The concordance of diagnosis before and after disclosure were significant and very good as doctor A by use of conventional film-reading method and profile-outlined one,Kappa values were 0.74 And 0.93. At the same time the concordance of diagnosis by 2 radiologists were weak and very good by the use of conventional film-reading method and profile-outlined one,Kappa values were 0.39 And 0.92.Conclusion Compared with conventional film reading method,profile-outlined method is better on consistency of CT diagnosis in the area of lumbar disc herniation.