Value of MR imaging in clinical evaluation of breast lesions

To evaluate the value of dynamic MR imaging as an adjunctive tool to triple diagnosis (TD) (physical examination, mammography and fine needle aspiration cytology) in diagnosing breast lesions.

Ninety-three consecutive patients with 114 palpable or mammographically detected breast lesions were examined with TD and MR imaging. The MR examination was performed dynamically using a dedicated breast coil. Five diagnostic groups were defined on a scale from 1=normal, to 5 = malignant, where groups 1-3 were defined as benign and groups 4-5 as malignant. All lesions were histopathologically examined. The sensitivity and specificity were calculated for mammography alone, TD, MR and the combination of MR and TD.

Histopathology revealed 32 benign and 82 malignant lesions (73 invasive and 9 cancer in situ). The sensitivity/specificity was 84%/59% for mammography, 93%/41% for TD, 94%/47% for MR and 99%/19% for TD + MR. In the 32 mammographically dense breasts, mammography/TD/MR/TD + MR had a sensitivity of 72%/94%/94%/100% and a specificity of 79%/57%/36%/29%, respectively.

MR imaging might be of value as an additive method to TD by increasing the sensitivity, but at the cost of decreasing specificity. Patients with mammographically dense parenchyma might have more benefit of the additive value, as the decrease in specificity in these patients was less pronounced in our study.