Apparent diffusion coefficient (ADC) value to evaluate BI-RADS 4 breast lesions: correlation with pathological findings.

Diffusion-weighted imaging and apparent diffusion coefficient (ADC) of 36 breast lesions previously categorized as 4 according to the Breast Imaging Reporting and Data System (BI-RADS) were prospectively studied. The pathological results were 21 benign lesions and 15 malignant. The ADC of malignant lesions was significantly lower than that of the benign ones (0.87 ± 0.12 × 10(-3) mm(2)/s vs. 1.41 ± 0.22 × 10(-3) mm(2)/s, respectively) (P<.001). Using a threshold ADC value of 1.08 × 10(-3) mm(2)/s, a sensitivity of 95% and specificity of 100% were obtained.