纹理分析对磁共振引导下聚焦超声术治疗症状性子宫肌瘤疗效的预测价值

Predictive Value of Texture Analysis in the Treatment of Magnetic Resonance-guided Focused Ultrasound Surgery for Symptomatic Uterine Fibroids

目的评估纹理分析对磁共振引导下聚焦超声术(MRg FUS)治疗症状性子宫肌瘤疗效的预测价值。方法以2010年4月至2013年1月在北京协和医院接受MRgFUS治疗的16例症状性子宫肌瘤患者为研究对象,在术前、术后即刻和术后12个月给予增强MRI检查,采用TexRAD软件对T2矢状位图像进行纹理分析得到纹理参数平均值、标准差(SD)、熵、正性像素的平均值(MPP)、偏度和峰度,测量目标肌瘤相关径线计算出子宫肌瘤体积及变化率,采用子宫肌瘤症状与生活质量问卷调查并计算出标准化症状严重程度评分(SSS)及变化率,比较各纹理参数在术前、术后即刻和术后12个月图像中的差异,研究治疗前后纹理参数与肌瘤评价参数间的相关性。结果术前肌瘤的平均体积为(96. 5±84. 9) cm3,术后12个月减小至(55. 1±71. 0) cm3,体积变化率(ΔV%)为(49±20)%;术前标准化SSS评分为(34. 18±15. 29)分,术后12个月降至(17. 78±11. 84)分,变化率为(45±32)%,无灌注区体积比(NPV%)为(62±20)%。术前、术后即刻和术后12个月间的纹理参数平均值、SD、熵和MPP差异均有统计学意义(P均<0. 05),其改变存在规律性,均表现为术后即刻明显降低,术后12个月又明显升高,且升高程度超过术前水平。相关性分析结果显示,术后即刻纹理参数SD (SSF2:r=0. 503,P=0. 047; SSF4:r=0. 529,P=0. 035; SSF6:r=0. 519,P=0. 039)和熵(SSF2:r=0. 527,P=0. 036; SSF4:r=0. 517,P=0. 040; SSF6:r=0. 495,P=0. 050)与ΔV%间有显著相关性;术前纹理参数熵与NPV%呈显著正相关(SSF2:r=0. 507,P=0. 045; SSF4:r=0. 543,P=0. 030; SSF6:r=0. 548,P=0. 028)。结论治疗前后MRI纹理参数的变化与MRgFUS治疗子宫肌瘤的疗效间存在一定相关性,纹理分析可能在MRgFUS对子宫肌瘤疗效预测中有一定应用价值。

Objective To evaluate the predictive value of texture analysis in the treatment of magnetic resonance-guided focused ultrasound surgery(MRgFUS)for symptomatic uterine fibroids.Methods Totally 16 patients with symptomatic uterine fibroids who accepted MRgFUS in Peking Union Medical College Hospital from April 2010 to January 2013 were included.Enhanced magnetic resonance imaging(MRI)was performed before treatment,immediately after treatment,and during the 12-month follow-up.The TexRAD software was used to measure the texture parameters of the fibroids in T2WI sagittal images,and the texture indicators including means and standard deviations(SD),entropy,mean of positive pixels(MPP),skewness,and kurtosis were collected.The fibroid’s volume and their change rates were calculated by measuring the relevant diameter of the target fibroid.The Uterine Fibroid Symptoms and Quality of Life(UFS-QOL)was used to calculate the symptom severity scores(SSS)and its change rate.The statistical difference of parameters among the groups was analyzed.The correlations between each texture parameter and the therapeutic outcome of the fibroids were analyzed respectively.Results The average volume for fibroids before treatment was(96.5±84.9)cm 3,which was reduced to(55.1±71.0)cm 3 after treatment for 12 months,and the volume change rate(ΔV%)was(49±20)%.The standardized SSS score before treatment was(34.18±15.29)scores,decreased to(17.78±11.84)scores 12 months after treatment,with a change rate of(45±32)%,and the non-perfused volume ratio(NPV%)was(62±20)%.There were significant differences among the parameters mean,SD,entropy,and MPP among three groups(all P<0.05),and the changes of them were regular,all of which showed a significant decrease immediately after treatment and a significant increase 12 months after treatment,and the increase degree was higher than the preoperative level.SD(SSF2:r=0.503,P=0.047;SSF4:r=0.529,P=0.035;SSF6:r=0.519,P=0.039)and entropy(SSF2:r=0.527,P=0.036;SSF4:r=0.517,P=0.040;SSF6:r=0.495,P=0.050)of the after-treatment group moderately associated with theΔV%.Entropy of the before-treatment group was moderately associated with NPV%(SSF2:r=0.507,P=0.045;SSF4:r=0.543,P=0.030;SSF6:r=0.548,P=0.028).Conclusion There is a certain correlation between the changes of MRI texture parameters before and after treatment and the effect of MRgFUS in the treatment of uterine fibroids,and texture analysis may have certain value in the predicting the effect of MRgFUS on uterine fibroids.