Detection of axillary node metastasis using diffusion-weighted MRI in breast cancer.

Breast magnetic resonance imagings (MRIs) including diffusion-weighted MRI (DWI) of 110 breast cancers (26 with pathologically proven axillary node metastasis and 84 without metastasis) were retrospectively studied. Axillary nodes were detected as high-signal-intensity areas on DWI in 71 cancers (24 with metastasis and 47 without) and not detected in 39 cancers (2 with metastasis and 37 without). The ADC of metastatic nodes was significantly greater than that of the benign ones (1.08 ± 0.18 × 10(-3) mm(2)/s vs. 0.92 ± 0.22 × 10(-3) mm(2)/s, P=.004). When detectability of axillary nodes on DWI and ADC over 1.05 × 10(-3) mm(2)/s was applied as a threshold, 53.8% sensitivity, 86.9% specificity, and 79.1% accuracy were provided.