Can the Kaiser Score with Breast MRI Improve Clarity for BI-RADS 0 and 4 Assessments on Mammography and Ultrasound?

Emerging research suggests that use of the Kaiser score with breast MRI offers significant prognostic insight for malignancy prediction for women who have had inconclusive or suspicious findings on mammography and breast ultrasound.

For the retrospective study, recently published in the European Journal of Radiology, researchers assessed the Kaiser score with a review of breast MRI data and histopathological data for 99 women who had prior BI-RADS 0 or BI-RADS 4 assessments on conventional imaging. Out of 91 patients who had prior breast ultrasound, 30 patients had breast cancer. Out of 34 patients with prior mammograms, 13 patients had breast cancer, according to the study.

Does the Kaiser Score Predict Malignancy Better Than the MRI BI-RADS System?

The study authors found that the Kaiser score at a scoring threshold of > 5 offered a 97.7 percent AUC in predicting malignancy in contrast to 87.8 percent for the MRI BI-RADS classification system using a threshold of > BI-RADS 4.

While the MRI BI-RADS system provided greater specificity than the Kaiser score (100 percent vs. 87.9 percent), the researchers noted that use of the Kaiser score demonstrated a nearly 37 percent higher sensitivity for predicting malignancy (97 percent vs. 60.6 percent) and a nearly 15 percent higher negative predictive value (NPV) (98.3 percent vs. 83.5 percent).

“Although MRI BI-RADS remains the standard reporting framework for breast MRI, the Kaiser score showed higher diagnostic performance in our cohort and offered a more structured distinction between benign and malignant lesions. This difference may be related to the fact that the Kaiser score integrates several morphologic and kinetic MRI features into a stepwise decision model, providing a structured approach to interpretation,” explained lead study author Ece Zengin, MD, who is affiliated with the Department of Radiology at Tokat Gaziosmanpasa University in Tokat, Turkey, and colleagues.

Emphasizing Caution with Use of the Kaiser Score in Breast Cancer Risk Assessments

However, the researchers also pointed out a high malignancy prevalence in the overall cohort (33.3 percent) and noted that one detected malignancy had a Kaiser score of 5, which would have been outside of the threshold for positive lesions. Accordingly, the study authors urged caution with adjunctive use of the Kaiser score.

“The Kaiser score should therefore support, rather than replace, clinical evaluation, conventional imaging, and MRI BI-RADS assessment; it should not be used alone to downgrade a lesion or withhold biopsy,” emphasized Zengin and colleagues.

(Editor’s note: For related content, see “Is the Kaiser Score More Effective than BI-RADS for Assessing Contrast-Enhanced Mammography and MRI?,” “New Meta-Analysis Assesses Use of the Kaiser Score for Breast MRI” and “New Breast MRI Study Says Background Parenchymal Enhancement Has No Impact on Lesion Detection.”)

Beyond the inherent limitations of a single-center retrospective study, the researchers acknowledged the small cohort size and that histopathological confirmation was not utilized for evaluation in all cases.