Résumé
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.
Résumé
OBJECTIVE@#To compare the performance of Clear Cell Likelihood Score (ccLS) v1.0 and v2.0 in diagnosing clear cell renal cell carcinoma (ccRCC) from small renal masses (SRM).@*METHODS@#We retrospectively analyzed the clinical data and MR images of patients with pathologically confirmed solid SRM from the First Medical Center of the Chinese PLA General Hospital between January 1, 2018, and December 31, 2021, and from Beijing Friendship Hospital of Capital Medical University and Peking University First Hospital between January 1, 2019 and May 17, 2021. Six abdominal radiologists were trained for use of the ccLS algorithm and scored independently using ccLS v1.0 and ccLS v2.0. Random- effects logistic regression modeling was used to generate plot receiver operating characteristic curves (ROC) to evaluate the diagnostic performance of ccLS v1.0 and ccLS v2.0 for ccRCC, and the area under curve (AUC) of these two scoring systems were compared using the DeLong's test. Weighted Kappa test was used to evaluate the interobserver agreement of the ccLS score, and differences in the weighted Kappa coefficients was compared using the Gwet consistency coefficient.@*RESULTS@#In total, 691 patients (491 males, 200 females; mean age, 54 ± 12 years) with 700 renal masses were included in this study. The pooled accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ccLS v1.0 for diagnosing ccRCC were 77.1%, 76.8%, 77.7%, 90.2%, and 55.7%, as compared with 80.9%, 79.3%, 85.1%, 93.4%, 60.6% with ccLS v2.0, respectively. The AUC of ccLS v2.0 was significantly higher than that of ccLS v1.0 for diagnosis of ccRCC (0.897 vs 0.859; P < 0.01). The interobserver agreement did not differ significantly between ccLS v1.0 and ccLS v2.0 (0.56 vs 0.60; P > 0.05).@*CONCLUSION@#ccLS v2.0 has better performance for diagnosing ccRCC than ccLS v1.0 and can be considered for use to assist radiologists with their routine diagnostic tasks.