磁共振扩散加权成像对子宫内膜癌的诊断价值

Value of high-field MR diffusion-weighted MR imaging in the diagnosis of endometrial carcinoma

目的应用高场强磁共振对子宫内膜癌进行扩散加权成像（DWI），并探讨其对子宫内膜癌的诊断价值。方法应用3．0T磁共振扫描仪，对临床怀疑为子宫内膜癌的50例患者（病理证实子宫内膜癌35例，子宫内膜不典型增生10例，分泌期子宫内膜4例，萎缩性子宫内膜1例）以及41例正常志愿者行常规扫描和DWI，DWI选择b值为1000s／mm^2。观察子宫内膜癌、正常子宫内膜和子宫内膜不典型增生在DWI图像上的差异，并分析三者间以及不同分化程度子宫内膜样腺癌之间表观扩散系数（ADC）值的差异。结果与周围正常肌层相比，子宫内膜癌、子宫内膜不典型增生和正常子宫内膜在DWI图像上均呈明显高信号。子宫内膜癌、子宫内膜不典型增生和正常子宫内膜的ADC值分别为（1．08±0．23）×10^-3mm^2／s、（1．29±0．21）×10^-3mm^2／s和（1．41±0．21）×10^-3mm^2／s。统计分析结果显示，子宫内膜癌和正常子宫内膜的ADC值之间以及子宫内膜癌与子宫内膜不典型增生的ADC值之间的差异均有统计学意义（均P〈0．05），但高分化子宫内膜样腺癌和中分化子宫内膜样腺癌的ADC值之间的差异无统计学意义（P=0．109）。结论DWI对检出子宫内膜病变非常敏感，能够鉴别子宫内膜癌、子宫内膜不典型增生和正常子宫内膜，但对于鉴别不同分化程度的子宫内膜样腺癌仍有一定的困难。

Objective To investigate the usefulness of high-field MR diffusion-weighted imaging （DWI） in the diagnosis of endometrial carcinoma. Methods Thirty-five female patients with pathologically proven endometrial carcinoma, 10 patients with pathologically proven endometrial dysplasia and 41 normal volunteers were enrolled into this study. MR images were obtained at a 3.0 T MR scanner （ GE, SIGNA EXCITE HD 3. 0T） and an 8-element phased-array torsopa coil was used to receive MR signal. The conventional pulse sequences included axial SE T1WI, FSE T2WI and fat saturated FSE T2WI, sagittal FSE T2WI, and coronal fat saturated FSE T2WI. Axial DWI was performed in all patients using a SE-EPI sequence with a 1000 s/mm^2 b value. The apparent diffusion coefficients （ADC） of carcinoma, dysplasia and normal mucosa were measured among the patients. Results Compared with myometrium, all the endometrial carcinoma, dysplasia and normal endometrium had a markedly high signal intensity on DWI. The ADC of endometrial carcinoma, dysplasia and normal endometrium was （1.08 ±0.23 ）×10^-3mm^2/s, （1.29±0.21）×10^-3mm^2/s and （1.41 ±0.21 ）×10^-3mm^2/s, respectively. There were statistically significant differences between the carcinoma and normal endometrium （ t = - 6. 416, P = 0. 000 ）, and between the carcinoma and dysplasia （t = -2.590, P = 0. 013 ）. However, no significant difference in ADC was found between highly-differentiated and moderately-differentiated adenocarcinomas. Conclusion High- field MR diffusion-weighted imaging （DWI） is highly sensitive in detecting endometrial lesions. It can be used to differentiate the endometrial carcinoma from either dysplasia or normal endometrium, but is difficult to differentiate highly-differentiated adenocarcinoma from moderately-differentiated one.