Apparent Diffusion Coefficient Values for Discriminating Benign and Malignant Breast MRI Lesions: Effects of Lesion Type and Size

Apparent Diffusion Coefficient Values for Discriminating Benign and Malignant Breast MRI Lesions: Effects of Lesion Type and Size
Savannah C. Partridge, Christiane D. Mullins, Brenda F. Kurland, Michael D. Allain, Wendy B. DeMartini, Peter R. Eby, and Constance D. Lehman
AJR 2010;194:1664-1673

Link to Journal

RESULTS. Sixteen of 71 masses and 13 of 45 lesions with nonmasslike enhancement were malignant. The mean ADC was significantly lower for malignant than for benign lesions for both masses (mean difference, 0.49 x 10–3 mm2/s; p < 0.001) and lesions with nonmasslike enhancement (mean difference, 0.20 x 10–3 mm2/s; p = 0.02). The area under the receiver operating characteristics curve (AUC) was greater for masses (AUC, 0.80) than for lesions with nonmasslike enhancement (AUC, 0.66). The mean ADC for malignant masses (1.25 x 10–3 mm2/s) was lower than that for malignant lesions with nonmasslike enhancement (1.41 x 10–3 mm2/s; p = 0.07). The median lesion size was 1.1 cm (range, 0.5–8.3 cm); 45 of 71 masses (63%) measured 1 cm or smaller, and 37 of 45 lesions with nonmasslike enhancement (82%) were larger than 1 cm. There was no relation (p > 0.05) between ADC value and lesion size for benign or malignant lesions, and there were no differences in AUC based on lesion size (p > 0.05).

CONCLUSION. Diffusion-weighted MRI shows promise in differentiation of benign and malignant masses and lesions with nonmasslike enhancement found at breast MRI and is not affected by lesion size. However, ADC measurements may be more useful for discriminating masses than for discriminating lesions with nonmasslike enhancement