The Blood Oxygenation T₂^* Values of Resectable Esophageal Squamous Cell Carcinomas as Measured by 3T Magnetic Resonance Imaging: Association with Tumor Stage

Objective: To explore the association between the blood oxygenation ${T_2}^*$ values of resectable esophageal squamous cell carcinomas (ESCCs) and tumor stages. Materials and Methods: This study included 48 ESCC patients and 20 healthy participants who had undergone esophageal ${T_2}^*$-weighted imaging to obtain ${T_2}^*$ values of the tumors and normal esophagi. ESCC patients underwent surgical resections less than one week after imaging. Statistical analyses were performed to identify the association between ${T_2}^*$ values of ESCCs and tumor stages. Results: One-way ANOVA and Student-Newman-Keuls tests revealed that the ${T_2}^*$ value could differentiate stage T1 ESCCs ($17.7{\pm}3.3ms$) from stage T2 and T3 tumors ($24.6{\pm}2.7ms$ and $27.8{\pm}5.6ms$, respectively; all $p_s$ < 0.001). Receiver operating curve (ROC) analysis showed the suitable cutoff ${T_2}^*$ value of 21.3 ms for either differentiation. The former statistical tests demonstrated that the ${T_2}^*$ value could not differentiate between stages T2 and T3 ($24.6{\pm}2.7ms$ vs. $27.8{\pm}5.6ms$, respectively, p > 0.05) or between N stages (N1 vs. N2 vs. N3: $24.7{\pm}6.9ms$ vs. $25.4{\pm}4.5ms$ vs. $26.8{\pm}3.9ms$, respectively; all $p_s$ > 0.05). The former tests illustrated that the ${T_2}^*$ value could differentiate anatomic stages I and II ($18.8{\pm}4.8ms$ and $26.9{\pm}5.9ms$, respectively) or stages I and III ($27.3{\pm}3.6ms$). ROC analysis depicted the same cutoff ${T_2}^*$ value of 21.3 ms for either differentiation. In addition, the Student's t test revealed that the ${T_2}^*$ value could determine grouped T stages (T0 vs. T1-3: $17.0{\pm}2.9ms$ vs. $25.2{\pm}6.2ms$; T0-1 vs. T2-3: $17.3{\pm}3.0ms$ vs. $27.1{\pm}5.3ms$; and T0-2 vs. T3: $18.8{\pm}4.2ms$ vs. $27.8{\pm}5.6ms$, all $p_s$ < 0.001). ROC analysis indicated that the ${T_2}^*$ value could detect ESCCs (cutoff, 20 ms), and discriminate between stages T0-1 and T2-3 (cutoff, 21.3 ms) and between T0-2 and T3 (cutoff, 20.4 ms). Conclusion: The ${T_2}^*$ value can be an additional quantitative indicator for detecting ESCC except for stage T1 cancer, and can preoperatively discriminate between some T stages and between anatomic stages of this tumor.