Interobserver agreement and diagnostic performance assessment of clear cell likelihood score using T 2WI with fat suppression technique / 中华放射学杂志

ABSTRACT

Objectives:To investigate the effect of fat suppression (FS) T 2WI on the interobserver agreement and diagnostic performance of clear cell likelihood score version 2.0 (ccLS v2.0) for clear cell renal cell carcinoma (ccRCC). Methods:In this retrospective study, the MR images of 111 patients with pathologically confirmed small renal masses (SRM) from January to December 2021 were analyzed in the First Medical Centre, Chinese PLA General Hospital. Of the 111 SRM, 82 cases were ccRCC and 29 cases were non-ccRCC. Two radiologists independently assessed ccLS scores based on T 2WI signal intensity (hypointense, isointense, hyperintense) and other MRI features (ccLS-T 2WI). After a one-month interval, the ccLS scores were independently evaluated utilizing the frequency-selective saturation FS-T 2WI and other MRI features (ccLS-FS-T 2WI). Fisher′s exact test was used to compare the difference in SRM signal intensity on T 2WI and FS-T 2WI. The weighted Kappa test was performed to assess the interobserver agreement of the two radiologists, and differences in the weighted Kappa coefficients were compared using the Gwet consistency coefficient. Receiver operating characteristic curves were drawn to evaluate the diagnostic performance of ccLS-T 2WI and ccLS-FS-T 2WI in diagnosing ccRCC, and the area under the curve (AUC) was compared utilizing the DeLong test. Results:The signal intensity of 111 SRM on T 2WI and FS-T 2WI had statistically significant difference (χ 2=126.33, P<0.001), consistent in 88 cases (79.3%) and varied in 23 cases (20.7%). The weighted Kappa coefficient of ccLS-T 2WI was 0.57 (95%CI 0.45-0.69) between the two radiologists, and the weighted Kappa coefficient of ccLS-FS-T 2WI was 0.55 (95%CI 0.42-0.67), and the difference was not statistically significant ( t=-0.65, P=0.520). The AUC of ccLS-T 2WI for ccRCC diagnosis was 0.92 (95%CI 0.86-0.97), while the AUC of ccLS-FS-T 2WI for ccRCC diagnosis was 0.91 (95%CI 0.85-0.96), and the difference was not statistically significant ( Z=1.50, P=0.133). Conclusions:The interobserver agreement and diagnostic performance of ccLS v2.0 based on T 2WI and FS-T 2WI sequences for ccRCC are comparable, and FS-T 2WI is applicable for the clinical application of ccLS v2.0.