Differentiation of fibroadenomas versus malignant breast tumors utilizing three-dimensional amide proton transfer weighted magnetic resonance imaging

Objective: To explore the value of amide proton transfer-weighted (APTw) magnetic resonance imaging (MRI) for differential diagnosis of fibroadenomas and malignant breast tumors.

Materials and methods: This prospective study enrolled 56 patients with suspected breast tumors and performed APTw imaging. Based on the histopathology results, patients were divided into group 1 with malignant breast tumors (n = 41) and group 2 with fibroadenomas (n = 15). The measured image parameters (APTw value, ADC value, type of Time of Intensity Curve, maximum tumor diameter in image) and the maximal diameter of the tumors measured from surgical resection were compared between the two groups, and the diagnostic performance based on these parameters was quantified with ROC curve. Spearman's correlation coefficient was used to analyze the association between APTw or ADC values and ER, PR, HER2, and Ki-67 expressions.

Results: The intraclass correlation coefficients (ICC = 0.87 and 0.91) indicated a good inter-observer agreement of the measured APTw values. APTw values of malignant lesions were significantly higher than those of fibroadenomas (3.21 ± 1.04% vs 1.50 ± 0.54%, p < 0.001). Area under the curve (AUC) obtained from APTw imaging, DWI, DCE, APTw imaging+DWI, APTw imaging+DWI, and APTw imaging+DWI + DCE was 0.959, 0.897, 0.976, 0.997, and 1 respectively. The APTw value showed a negative correlation with ER expression (r = -0.357).

Conclusion: APTw imaging yielded similar diagnosis performance in discriminating fibroadenomas and malignant breast tumors when compared to the DCE and better than DWI imaging, and provided supplement information on tumor cell activity to DWI images. The APTw value showed correlations with some prognostic factors for breast cancer.