OBJECTIVE: Our study aimed to investigate the effectiveness of Kaiser Score (KS) in diagnosing Non-mass enhanced (NME) lesions and its impact on the inter-reader agreement between experienced and inexperienced readers. MATERIALS AND METHODS: A retrospective analysis was conducted on 189 NME lesions from 182 MRIs. Two readers (an experienced radiologist and a radiology resident) independently evaluated lesions using the KS, blinded to clinical and pathological data. The KS was modified (MKS) by adding 2 points for microcalcifications on mammography and subtracting 4 points for ADC values >
1.4 x 10^-3 mm RESULTS: Interobserver agreement improved with MKS (ICC: 0.763) compared to KS (ICC: 0.667). For the experienced reader, both KS and MKS achieved high sensitivity (>
94 %) at a cut-off of >
4. At >
5, specificity improved from 40.5 % to 58.7 % for KS and 39.1 % to 55.8 % for MKS without significantly affecting sensitivity. For the inexperienced reader, MKS improved sensitivity (96.8 %) and specificity (39 %) at >
4. At >
5, specificity increased to 55.8 %, with a non-significant decrease in sensitivity (86.2 %). CONCLUSION: The Kaiser Score is a quick and systematic tool that enhances diagnostic accuracy and reduces biopsy rates, particularly benefiting inexperienced readers. While higher thresholds improve specificity for experienced readers, they may reduce sensitivity for inexperienced readers, potentially missing malignancies. As a complement to BI-RADS, the Kaiser Score helps standardize evaluations and bridge experience gaps in MRI interpretation.