不同b值的弥散加权成像评价子宫肌瘤高能聚焦超声术后消融疗效的效果观察

The efficacy of diffusion-weighted imaging using different b-value combinations for the evaluation of treatment results after high-intensity focused ultrasound ablation of uterinefibroids

目的:探究应用不同b值下弥散加权成像(diffusion-weighted imaging,DWI)对于子宫肌瘤高能聚焦超声术后消融疗效评价的效果。方法:选择于2016年1月至2017年6月间于海南医学院第二附属医院就诊的29例子宫肌瘤患者,在行高能聚焦超声消融后行核磁共振成像对消融效果进行评价,比较不同b值DWI成像下消融和未消融区域表观扩散系数(apparent diffusion coefficient,ADC)的差异;以核磁共振增强扫描为金标准,评价不同b值DWI成像下ADC值对消融和未消融区域的鉴别效能以及消融效果分级与CE-MRI间的一致性。结果:b=200和b=600时,术前、消融部位和未消融部位ADC值间差异具有统计学意义(P <0. 05); b=1000时术前、消融部位和未消融部位ADC值间差异无统计学意义(P> 0. 05)。ROC曲线显示,b=200的DWI成像下ADC值对消融和未消融区域的AUC最高(AUC=0. 918,P <0. 001),b=600次之(AUC=0. 716,P=0. 001),b=1000最低(AUC=0. 651,P=0. 021)。一致性检验显示,b=200的DWI成像下消融效果分级与CE-MRI间的一致性最高(ICC=0. 933,P <0. 001),b=600次之(ICC=0. 671,P <0. 001),b=1000的一致性较差(ICC=0. 306,P=0. 051)。结论:较低的b值(b=200)能够较好地区分HIFU术后消融和未消融区域,可以更好地评价消融效果。

Objective:To observe the efficacy of diffusion-weighted imaging(DWI)using different b-value combinations for the evaluation of treatment results after high-intensity focused ultrasound ablation of uterine fibroids.Methods:29 patients with uterine fibroids in the Second Affiliated Hospital of Hainan Medical University from January 2016 to July 2017 were selected and treated by high-intensity focused ultrasound ablation.Differences in apparent diffusion coefficient(ADC)between the ablated and non-ablated tissues of DWI using different b-value were compared.The discriminant efficacy of ADC values on ablation and ablation areas under different b values of DWI imaging and the consistency between ablation effect and magnetic resonance imaging enhanced scan(CE-MRI)were comparatively analyzed with CE-MRI as the gold standard.Results:When b=200 and b=600,there were significant difference in ADC value between before operation,ablation site and non-ablation site(P<0.05),while there was no statistically significant difference when b=1000(P>0.05).The ROC curve showed that the ADC value of b=200 DWI imaging has the highest AUC of ablation and non-ablation regions(AUC=0.918,P<0.001),followed by b=600(AUC=0.716,P=0.001),and that of b=1000 was lowest(AUC=0.651,P=0.021).Consistency test showed that b=200 DWI imaging had the highest degree of consistency,with CE-MRI ablation(ICC=0.933,P<0.001),followed by b=600(ICC=0.671,P<0.001),and the consistency of b=1000 was poor(ICC=0.306,P=0.051).Conclusions:The lower b value(b=200)is conducive to distinguishing the postoperative ablation and ablation areas of HIFU,thusly better evaluating the ablation effect.