Estimation of T2^* Relaxation time of breast cancer: Correlation with clinical, imaging and pathological features

Objective: The purpose of this study was to estimate the T2^* relaxation time in breast cancer, and to evaluate the association between the T2^* value with clinical-imaging-pathological features of breast cancer. Materials and Methods: Between January 2011 and July 2013, 107 consecutive women with 107 breast cancers underwent multi-echo T2^*-weighted imaging on a 3T clinical magnetic resonance imaging system. The Student’s t test and one-way analysis of variance were used to compare the T2* values of cancer for different groups, based on the clinical-imagingpathological features. In addition, multiple linear regression analysis was performed to find independent predictive factors associated with the T2^* values. Results: Of the 107 breast cancers, 92 were invasive and 15 were ductal carcinoma in situ (DCIS). The mean T2^* value of invasive cancers was significantly longer than that of DCIS (p = 0.029). Signal intensity on T2-weighted imaging (T2WI) and histologic grade of invasive breast cancers showed significant correlation with T2^* relaxation time in univariate and multivariate analysis. Breast cancer groups with higher signal intensity on T2WI showed longer T2^* relaxation time (p = 0.005). Cancer groups with higher histologic grade showed longer T2^* relaxation time (p = 0.017). Conclusion: The T2^* value is significantly longer in invasive cancer than in DCIS. In invasive cancers, T2^* relaxation time is significantly longer in higher histologic grades and high signal intensity on T2WI. Based on these preliminary data, quantitative T2^* mapping has the potential to be useful in the characterization of breast cancer.