MRI扩散加权成像对女性附件复杂肿块预测良恶性的临床应用价值

The application of diffusion-weighted MR imaging for predicting benignity or malignancy of complex adnexal masses

目的探讨MRI扩散加权成像在女性附件复杂肿块鉴别诊断中的应用价值。方法对103例女性附件复杂肿块进行常规的MRI和DWI检查,所有病例均经手术病理证实。前瞻性比较常规图像、DWI特征(b=800s/mm2)、相对信号强度(RSI)值及ADC值的良恶性差异及计算预测良性和恶性的阳性似然比(PLR)。结果女性附件复杂肿块囊性成分的ADC值、RSI值在良性(36例)、恶性(32例)之间无显著性差异[(23.87±7.12)×10-4mm2/s、(25.69±3.78)×10-4mm2/s,2.82±2.09、2.81±1.50,P均>0.05〗。实性RSI值在良性(24例)、恶性(43例)之间有显著性差异(2.97±2.18、4.62±3.31,P<0.05),实性ADC值在良恶性之间无显著性差异[(15.29±4.45)×10-4mm2/s、(13.94±3.95)×10-4mm2/s,P>0.05]。以病变实性部分的RSI值≥5.91为阈值预测恶性,PLR为5.02。复杂附件肿块实性部分在T2WI和DWI图像上均为低信号基本上是良性(PLR为∞),然而T2WI中等信号同时DWI高信号预测恶性的PLR为3.93。结论结合常规MRI,DWI能准确预测良性女性附件复杂肿块,对预测恶性准确性较低。

Objective To prospectively assess the contribution of diffusion-weighted MR imaging （DWI） for characterizing complex adnexal masses. Methods 103 women with complex adnexal masses were confirmed by pathology and underwent MR imaging including DWI before surgery. Conventional morphological MR imaging criteria were prospectively recorded in addition to relative signal intensity （RSI） value and apparent diffusion coefficient （ADC） value on DWI （b =800 s/mm^2） measurements of cystic and solid components. Positive likelihood ratios （PLR） were calculated for predicting benignity and malignancy. Results ADC and RSI value of cystic components measurements did not contribute to differentiating benign （36 cases） from malignant （32 cases） adnexalmasses [（23.87±7.12） ×10^-4 mm^2/s, （25.69±3.78） ×10^-4 mm^2/s, 2.82±2.09, 2.81 ± 1.50, all P 〉 0. 053. There was significant difference of RSI value of solid components between benign （24 cases） and malignant （43 cases ） adnexal masses （2.97 ± 2.18, 4.62 ± 3.31, P 〈 0.05）, while, no significant difference of ADC [ （15.29± 4.45）×10^-4 mm^2/ s, （ 13.94±3.95）×10^-4 mm^2/s, P 〉0. 051. The PLR was 5.02 by using a threshold RSI mean value of solid components greater than or equal 5.91 for predicting malignancy. All masses that displayed simultaneously low signal intensity within the solid component on T2-weighted and on b800 DWI were benign. Alternatively, the presence of a solid component with intermediate T2 signal and high b800 signal intensity was associated with a PLR of 3.93 for a malignant adnexal tumor. Conclusion DWI signal intensity combined with routine MRI is an accurate tool for predicting benignity of complex adnexal masses, being a lower accurate tool for predicting malignancy.