Objective: To investigate the value of T2 map and synthetic T2WI generated by T2 mapping in evaluating the histological type, pathological classification and depth of myometrial invasion of endometrial carcinoma (EC). Methods: Seventy-three patients with pathologically proven EC diagnosed at the First Affiliated Hospital of Zhengzhou University from December 2019 to December 2021 and 42 healthy volunteers were enrolled in the study. All subjects underwent conventional MRI, diffusion weighted imaging (DWI) and T2 mapping sequence for the pelvic cavity to test the T2 values and the apparent diffusion coefficient (ADC) of the focus nidus of the patients and the normal endometrium of the volunteers. The T2 and ADC values of EC vs normal endometrium, and those of different histological types and pathological grades were compared. The receiver operating characteristic (ROC) curves were constructed to evaluate the diagnostic performance of T2 and ADC values in determining the pathological type and classification of EC. In addition, two radiologists used synthetic T2WI combined with T2 map and conventional T2WI combined with DWI, respectively, to evaluate the depth of myometrial invasion, and compared the imaging results with the results of pathological diagnosis to evaluate the diagnostic efficacy of the two methods in determining the depth of myometrial invasion. Results: The T2 and ADC values of endometrial carcinoma were 85.0 (80.8, 92.5) ms and 0.71 (0.64, 0.77) ×10(-3) mm(2)/s, respectively, which were significantly lower than those of normal endometrium [147.4 (123.4, 176.7) ms and 1.46 (1.26, 1.76)×10(-3) mm(2)/s, respectively; both P<0.05]. The T2 values of endometrioid carcinoma (EA) [84.1 (79.5, 88.7) ms] were significantly lower than those of non-EA [98.8 (92.1, 102.8) ms; P<0.05]. There was no significant difference in ADC values between EA and non-EA (P=0.075). The T2 values of G1, G2 and G3 groups in EA were 89.1 (84.4, 94.4) ms, 83.6 (80.9, 86.2) ms, and 76.5 (71.4, 80.3) ms, respectively. There were significant differences in the T2 values between G1 vs G2, G1 vs G3, and G2 vs G3 groups, respectively (all P<0.017). Significant difference was also found in the ADC values between the G1 and G3 groups (P<0.017). The area under the ROC curve (AUC) of T2 values in distinguishing EA from non-EA was 0.867. The AUC of T2 values, ADC values and their combination in predicting high-grade EA was 0.888, 0.730 and 0.895, respectively. The accuracy of synthetic T2WI+ T2 map and conventional T2WI+ DWI in the diagnosis of deep myometrial invasion was 78.1% and 79.5%, respectively, with no significant difference (P>0.05). Conclusions: T2 mapping has great potential in preoperative evaluation of EC. The quantitative T2 value can be used in the diagnosis, pathological classification and grading of EC. The combination of synthetic T2WI and T2 map may be helpful to determine the depth of myometrial invasion.
目的： 探讨基于磁共振T2 mapping技术生成的合成T2WI和T2 map图像在鉴别子宫内膜癌组织类型、病理级别和肌层浸润深度中的应用价值。 方法： 对2019年12月至2021年12月在郑州大学第一附属医院经病理确诊为子宫内膜癌的患者73例、健康志愿者42例，分别行常规盆腔磁共振成像(MRI)、扩散加权成像(DWI)和T2 mapping序列检查，测定子宫内膜癌患者病灶和健康志愿者正常子宫内膜的T2值和表观扩散系数(ADC)。比较子宫内膜癌与正常子宫内膜、肿瘤不同组织类型、不同病理级别间T2值和ADC值的差异，采用受试者工作特征(receiver operating characteristic, ROC)曲线分析评估T2值和ADC值对子宫内膜癌病理类型和病理分级的诊断效能。由2名磁共振科医师分别应用合成T2WI与T2 map、常规T2WI与DWI融合图像评估肌层浸润深度，与病理诊断结果进行比较，评价其对肌层浸润深度的诊断效能。 结果： 子宫内膜癌的T2值和ADC值分别为85.0(80.8，92.5)ms和0.71(0.64，0.77)×10(－3) mm(2)/s，均低于正常子宫内膜[分别为147.4(123.4，176.7)ms和1.46(1.26，1.76)×10(－3) mm(2)/s，均P<0.001]。子宫内膜样癌的T2值[84.1(79.5，88.7)ms]低于非子宫内膜样癌[98.8(92.1，102.8)ms，P＝0.001]，但子宫内膜样癌与非子宫内膜样癌的ADC值差异无统计学意义(P＝0.075)。病理分级G1、G2和G3子宫内膜样癌的T2值分别为89.1(84.4，94.4)、83.6(80.9，86.2)和76.5(71.4，80.3)ms，G1与G2、G1与G3、G2与G3间差异均有统计学意义(均P<0.017)，但ADC值仅在G1与G3组间差异有统计学意义(P<0.017)。以T2值鉴别子宫内膜样癌与非子宫内膜样癌的ROC曲线下面积(AUC)为0.867；T2值、ADC值及T2值联合ADC值预测高级别(G3)子宫内膜样癌的AUC分别为0.888、0.730和0.895。合成T2WI与T2 map融合图像、常规T2WI与DWI融合图像诊断子宫内膜癌深肌层浸润的准确性分别为78.1%和79.5%，差异无统计学意义(P＝0.840)。 结论： T2 mapping技术在子宫内膜癌术前评估中具有较大应用价值，定量参数T2值可用于子宫内膜癌的诊断、病理分型与分级，合成T2WI联合T2 map有助于肌层浸润深度的判定。.
Keywords: Endometrial neoplasms; Magnetic resonance imaging; Pathological characteristics; T2 mapping.