子宫内膜良、恶性息肉样病变的MR表现与临床病理对照分析

MR imaging of endometrial benign and malignant polypoid lesions： correlations with elinicopathological findings

目的探讨常规MR及动态增强扫描在子宫内膜息肉样病变中的诊断价值及病理基础。方法回顾性分析经病理证实的子宫内膜息肉样病变48例，其中恶性肿瘤26例（23例I期子宫内膜癌和3例子宫内膜肉瘤），良性息肉样病变22例（子宫内膜息肉12例和子宫黏膜下肌瘤10例），分析其MR平扫及增强图像病灶特征，并与病理结果进行对照。采用Fisher精确概率法对纤维核、囊变区及完整结合带在不同子宫内膜息肉样病变中的出现概率进行分析比较。结果26例子宫内膜恶性息肉病变，其中23例子宫内膜癌在MRT2WI上均表现为子宫内膜均匀等或稍高信号肿块（23／23），增强后相对于肌层均呈低信号（23／23），并伴结合带中断或模糊（20／23）；子宫内膜含间质成分恶性肿瘤3例，2例为腺肉瘤，1例为癌肉瘤，MRT2WI均为混杂信号，早期局部明显强化，至后期仍明显持续强化；26例子宫内膜恶性息肉病变在MR／上子宫结合带中断或模糊征象出现的概率（23／26）均较子宫内膜息肉（1／11）及子宫黏膜下肌瘤（1／9）高，差异具有统计学意义（P值均〈0．05）。肿块内小囊变影及不定形纤维核影见于子宫内膜息肉（分别为8／12及5／12），2种征象在子宫内膜息肉中的出现概率均较子宫内膜恶性息肉样病变（3／26及2／26）及子宫黏膜下肌瘤（0及2／10）高，差异具有统计学意义（P值均〈0．05）；10例子宫黏膜下平滑肌瘤MRI均表现为境界清晰，T2WI呈等或稍低信号肿块，且出现子宫黏膜推移征象（10／10）。MR平扫及增强扫描对所有48例子宫内膜息肉样病变的定性诊断敏感度为92．3％（24／26），特异度为83．3％（20／24），准确度为95．8％（46／48）。结论MRI平扫及增强扫描能反映子宫内膜良、恶性息肉样病变的特征，具有很高的诊断价值。

Objective To investigate the diagnostic value of conventional and dynamic gadoliniumenhanced T1-weighted （T1W） MRI in benign and malignant endometrial polypoid lesions. The pathologic basis of MRI features was also evaluated. Methods The conventional and dynamic contrast enhanced MRI features in 48 cases with clinicopathologically-proved endometrial polypoid lesions were retrospectively analyzed, including 26 cases with malignant tumors （ 23 cases with endometrial carcinoma and 3 cases with endometrial sarcoma ） and 22 cases with benign polypoid lesions （ 12 cases with endothelial polyps and 10 cases with submucous leiomyomas）. The occurrence probability of central fibrous core, intratumoral cysts and intact junctional zone were evaluated by Fisher＇s exact test. Results Benign and malignant endometrial polypoid lesions had specific characteristics on MRI. Endometrial carcinomas usually appeared as homogeneous intermediate or slightly high signal-intensity masses on T2-weighted images, and relatively homogeneous hypodense masses on contrast-enhanced images with myometrial invasion （P 〈 0. 05 ）. An irregular central fibrous core and small non-enhanced intratumoral cysts were seen more frequently in endometrial polyps （P 〈 0. 05 ） than others. All 3 cases with uterine sarcomas showed obviously inhomogeneous intensity on T2WI and demonstrated areas of early and persistent marked enhancement. Submucous leiomyomas demonstrated isodense or slightly low-density masses with defined outline on T2 WI and the endomerium was displaced. The diagnostic sensitivity, specificity and accuracy of malignant polypoid masses were 92. 3% （ 24/26 ）, 83. 3% （ 20/24 ） and 95. 8% （ 46/48 ） respectively. Conclusion Conventional and dynamic contrast-enhanced MRI are valuable in characterizing the benign and malignant endometrial polypoid lesions.