卵巢卵泡膜纤维瘤MRI表现与病理对照分析

Contrast analysis between MRI features of ovarian theca fibroma and histopathology

目的 探讨卵巢卵泡膜纤维瘤（OTF）MRI表现特点,并与组织病理学表现进行对照分析,旨在提高OTF诊断的准确率.方法 回顾性分析2005年1月至2016年12月33例OTF患者的MRI表现,并将MRI信号特征及强化强度与组织病理学表现进行对照分析.结果 33例OTF患者肿块最大直径2.5～18.0（6.65±4.46）cm.实质性22例,T2WI和T2WI脂肪抑制均呈等、低混杂信号,其间有细条状稍高或高信号;T1WI均呈较均匀低信号.囊实性11例,其中7例以实性为主,4例囊实性成分相等;实性区T2WI和T2WI脂肪抑制均呈等、低信号,其间有小斑片状稍高或高亮信号;囊变区T2WI和T2WI脂肪抑制均呈高信号;实性区、囊变区T1WI呈均匀低信号.增强表现：33例实质部分均呈轻度强化,其中见实质部分呈均匀强化14例,不均匀强化19例.动脉期33例均呈轻度强化;门静脉期显著强化15例,轻度强化18例;延迟期持续强化21例,强化程度减退12例.组织病理学表现与MRI对照显示：22例实质性肿瘤镜下见纤维细胞显著者,T2WI和T2WI脂肪抑制示实质部分呈等或低信号,T1WI呈均匀低信号;11例囊实性肿瘤镜下见胶原纤维少,瘤细胞比例较高者,T2WI上见实质部分呈等和稍高信号,T1WI呈低信号.结论 OTF的MRI表现具有一定特性,实性区T2WI呈低、等信号,增强动脉期轻度强化,门静脉期和延迟期持续强化有助于卵泡膜纤维瘤的诊断.

Objective To investigate the MRI features of ovarian theca fibroma （OTF） and compare it with histopathology features in order to improve the accuracy of OTF diagnosis. Methods The clinical data of 33 patients with OTF which were confirmed by surgical pathology from January 2005 to December 2016 were analyzed retrospectively. The signal characteristics and intensities of MRI were compared with histopathology features. Results The lump largest diameter of 33 patients with OTF was 2.5 to 18.0 （6.65 ± 4.46） cm. The substantial lump was in 22 cases. T2WI and T2WI fat suppression imaging showed a low or equal mixed signal among which there was slightly high or high signal, and T1WI imaging showed relatively uniform low signal. The cystic and solid lump was in 11 cases, including 7 cases of solid lumps and 4 cases of cystic-solid lumps, T2WI and T2WI fat suppression imaging of solid area showed equal or low signal among which there were a small patchy high or slightly high signal, and T2WI and T2WI fat suppression of cystic areas showed high signal; T1WI of solid and cystic areas showed uniform low signal. Enhanced appearance： in the 33 cases of enhancement, the parenchyma part showed mild enhancement, of which 14 cases were equal enhancement, 19 cases were uneven enhancement. During the arterial phase, all of 33 cases showed mild enhancement; 15 cases were obviously enhanced and 18 cases were mildly enhanced in the portal vein phase; 21 cases remained enhanced and the enhanced intensity of 12 cases decreased in the delayed phase. Comparison of histopathology features with MRI features showed that there were a higher proportion of fibrous cells under the microscope in 22 cases of parenchymal tumor, in which the fat suppression image of T2WI and T2WI showed equal or low signal in parenchyma, and T1WI showed even low signal; and there were a higher proportion of tumor cells and less collagen fibers under the microscope in 11 cases of cystic-solid tumor, in which the T2WI showed a slightly equal and higher signal and T1WI showed low signal in parenchyma. Conclusions The MRI features have some characteristics, such as low and equal signal of T2WI in parenchyma, mild enhancement during arterial phase and continuous enhancement in portal vein and delayed phase, which is helpful for diagnosis of OTF.