Equivalent cross-relaxation rate imaging of axillary lymph nodes in breast cancer.

PURPOSE: To determine whether equivalent cross-relaxation rate (ECR) imaging (ECRI) is a feasible method for optimization of axillary lymph node dissection (ALND) and thereby improve quality-of-life (QOL).

MATERIALS AND

METHODS

A total of 50 breast cancer patients underwent ECRI, with off-resonance saturation pulse at frequency offset of 5 ppm. ECR threshold values were determined to evaluate metastases to lymph nodes in the ALND group before examining the relationship between ECR value and cellular density. Metastases to lymph nodes of the sentinel lymph node biopsy (SLNB) group were evaluated based on the results of the ALND group.

RESULTS

In the ALND group, regions without metastases showed a higher cellular density and ECR value than those with metastases. The relationship of ECR value to cellular density formed two clusters according to the presence or absence of metastasis; cellular density was related to ECR value for both clusters. In the SLNB group, supposing a threshold ECR value of 80%, sensitivity and specificity were 88.2% and 100%, respectively.

CONCLUSION

ECRI is a potentially useful method for cellular density imaging of axillary lymph nodes. ECRI provides active information that enables ALND to be avoided, thus improving QOL.