Diagnostic performance of the Kaiser score for characterizing lesions on breast MRI with comparison to a multiparametric classification system.

PURPOSE: To determine the diagnostic performance of the Kaiser score and to compare it with the BI-RADS-based multiparametric classification system (MCS). METHOD: Two breast radiologists, blinded to the clinical and pathological information, separately evaluated a database of 499 consecutive patients with structural 3.0 T breast MRI and 697 histopathologically verified lesions. The Kaiser scores and corresponding MCS categories were recorded. The sensitivity and specificity of the Kaiser score and the MCS categories to differentiate benign from malignant lesions were calculated. The interobserver reproducibility and receiver operating characteristic (ROC) parameters were analysed. RESULTS: The sensitivity and specificity of the MCS were 100 % and 12 %, respectively, and those of the Kaiser score were 98.5 % and 34.8 % for reader 1 and 98.7 % and 47.5 % for reader 2. The area under the ROC-curve was 85.9 and 87.6 for readers 1 and 2. The interobserver intraclass correlation coefficient was excellent at 0.882. Reader 1 upgraded six lesions from BI-RADS 3 to a Kaiser score of >4, and reader 2 upgraded seven lesions. When applying the Kaiser score to 158 benign lesions readers 1 and 2 would have reduced the biopsy rate by 22.8 % and 35.4 %, respectively. CONCLUSIONS: The Kaiser score showed high diagnostic accuracy with excellent interobserver reproducibility. The MCS had perfect sensitivity but low specificity. Although the Kaiser score had slightly lower sensitivity, its specificity was 3-4 times greater than that of the MCS. Thus, the Kaiser score has the potential to considerably reduce the biopsy rate for true negative lesions.

Galactography is not an obsolete investigation in the evaluation of pathological nipple discharge.

PURPOSE: To evaluate the malignancy rate and diagnostic performance of galactography in patients with pathological nipple discharge (PND) after negative clinical breast examination, mammography and ultrasound. MATERIALS AND METHODS: We retrospectively evaluated all galactograms obtained between January 2006 and December 2014 in women with PND. Galactographic findings were classified into 6 groups according to a modified Galactogram Image Classification system (GICS) to comply with the breast imaging reporting and data system classification. Observers were blinded to the final histology and clinical outcome at the time of analysis. MRI was performed as a problem solving ancillary examination. Imaging findings, pathological diagnosis and follow-up data were evaluated. The diagnostic performance of MRI and technically successful galactography in the detection of neoplastic or risk lesions were separately calculated. RESULTS: A total of 146 patients with PND (mean age, 51.5 years; range, 17-93) were examined. Malignant lesions were detected in only 4 patients (2.7%) and risk-lesions in 5 patients (3.4%). Only one low-grade ductal carcinoma in situ was missed by galactography (GICS 1) and MRI. MRI examinations were performed in 21 (14.4%) patients; one of these patients (4.8%) had a malignant finding (GICS 0), two (9.5%) had risk-lesions (GICS 2 and 5). In the detection of neoplastic or risk lesions the sensitivity and specificity of galactography were 77.4% and 75.7% and of MRI 85.7% and 71.4%, consecutively. CONCLUSION: The malignancy rate is negligible if clinical, mammography, ultrasound and galactography examinations are negative. Galactography remains a practical, valuable and cost-effective examination procedure. If galactography is technically unsuccessful, MRI should be considered as an additional ancillary tool to evaluate the possible etiology of symptoms, but the routine use of MRI in all patients cannot be justified.