Objective:

Several studies have shown that diffusion weighted imaging (DWI) can serve as a powerful tool for differentiating benign from malignant breast lesions. In addition to this use, DWI may also be used in the assessment of axillary lymph nodes, since they show similar tissue characteristics to the primary tumor.

Materials and Methods:

We applied dynamic contrast enhanced breast magnetic resonance imaging and DWI to 110 female patients and 214 breasts. Apparent diffusion coefficient (ADC) values of 187 lymph nodes (142 benign and 45 malignant) in 177 axillae were measured. Malignant lymph nodes were diagnosed histopathologically, benign lymph nodes were diagnosed clinically and with imaging findings.

Results:

The mean ADC values were 1.00x10-3 mm2/s for the malignant, and 1.39x10-3 mm2/s for the benign lymph nodes. The ADC values of malignant lymph nodes were significantly lower than the benign ones (p=0.001). When 1.22x10-3 mm2/s was accepted as the cut-off ADC value, a sensitivity of 75.6% and a specificity of 71.1% were detected.

Conclusion:

Our preliminary data suggest that ADC measurements might be useful in differentiating malignant from benign axillary lymph nodes in the preoperative period. Further studies on a larger scale will increase confidence in the results of DWI.

Keywords: Diffusion weighted, magnetic resonance imaging, breast cancer, lymph nodes