Abstract
Purpose To correlate quantitative T1, T2, and proton density (PD) values from synthetic MRI with breast cancer subtypes. Methods Twenty-eight breast cancer patients underwent MRI of the breast including synthetic MRI. T1, T2, and PD values were correlated with Ki-67. T1, T2, and PD values were compared between estrogen receptor (ER) positive and ER negative cancers, and between Luminal A and Luminal B cancers. The effectiveness of T1, T2, and PD in differentiating the ER-negative from the ER-positive group and Luminal A from Luminal B cancers was evaluated using receiver operating characteristic analysis.Results Mean T2 relaxation of ER-negative cancers was significantly higher than that of ER-positive cancers (p < .05). The T1, T2, and PD values exhibited a strong positive correlation with Ki-67 (Pearson's r = 0.75, 0.69, and 0.60 respectively; p < .001). Among ER-positive cancers (n=23), T1, T2, and PD values of Luminal A cancers were significantly lower than those of Luminal B cancers (p < .05). The areas under the curve (AUCs) of T1, T2, and PD for discriminating ER-negative from ER-positive cancers were 0.74 (95% confidence interval (CI): 0.54-0.88), 0.87 (95% CI: 0.69-0.97), and 0.62 (95% CI: 0.42-0.79), respectively. The AUCs of T1, T2, and PD values for discriminating Luminal A from Luminal B cancers were 0.83 (95% CI: 0.61-0.95), 0.75 (95% CI: 0.52-0.90), and 0.75 (95% CI: 0.53-0.91), respectively.Conclusion Quantitative values from synthetic MRI significantly correlate with subtypes of invasive breast cancers and may classify subtypes with reasonably good accuracy.