Evaluating Diagnostic Performance of Kaiser Score and BI-RADS in MRI Examination of Suspicious Breast Lesions: a Retrospective Study
Abstract
Background: The purpose of the study is to compare the diagnostic performance of the Kaiser score (KS) with BI-RADS in breast magnetic resonance imaging (MRI) examination and to evaluate the impact of apparent diffusion coefficient (ADC), background parenchymal enhancement (BPE), and lesion type on its diagnostic efficacy.
Methods: This retrospective study included a total of 259 patients with 284 suspicious breast lesions. All patients underwent MRI examination using standardized protocols. Two blinded radiologists independently evaluated lesions using BI-RADS, KS, and ADC values. Histopathology served as the main reference standard. Diagnostic performance of BI-RADS, KS, ADC, as well as combination of KS and ADC (Kaiser Plus) were evaluated using sensitivity, specificity, and AUC values. Also, subgroup analyses for mass/non-mass lesions and background parenchymal enhancement (BPE) were performed.
Results: The AUC for BI-RADS, KS, ADC, and Kaiser Plus were 0.961 (95% CI = 0.931 to 0.980), 0.955 (95% CI = 0.924 to 0.976), 0.866 (95% CI = 0.807 to 0.913), and 0.959 (95% CI = 0.919 to 0.983), respectively. BI-RADS showed higher sensitivity (100% vs. 88.2%) but lower specificity (75.3% vs. 94.4%) than KS, resulting in comparable AUCs (DeLong p = 0.651). KS reduced unnecessary biopsies by 19.1% (17 benign lesions spared) but missed 11.7% more malignancies (n=23). For mass lesions, KS performance was improved, achieving superior specificity (94.6% vs. 75.7%) with minimal sensitivity trade-offs (93.0% vs. 100%) compared to BI-RADS. Non-mass lesions posed challenges for all methods. Also, KS performance was not different across BPE grades.
Conclusion: The KS showed comparable diagnostic value compared to BI-RADS, reducing unnecessary biopsies, without significant improvement from ADC integration. It also provided consistent performance across lesion types. Our findings support KS's clinical utility for breast MRI interpretation.
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