3.0T MRI弥散加权成像对子宫肌瘤高强度聚焦超声术后早期评价

Evaluation of early efficiency after high-intensity focused ultrasound operation on uterine fibroids by 3.0 T MRI-DWI

目的采用3.0T MRI弥散加权成像(DWI)对子宫肌瘤(HIFU)早期疗效评价。方法 33例子宫肌瘤患者,其中单发肌瘤20例,多发肌瘤13例,共59枚,平均年龄(34.3±8.7)岁,所有各患者均于HIFU术前及术后1 d行MRI平扫、增强扫描及DWI检查,观察并定量测定肌瘤HIFU术前、后T1增强扫描及DWI(ADC)信号值及术后消融区最大消融面积,对其疗效进行评估。结果 59枚肌瘤于HIFU术后在T1增强扫描序列均出现无灌注低信号消融区,消融率达70.9%。术后DWI显示的消融区与增强扫描显示消融区具有高度相关性(r=0.97)。术后35枚肌瘤消融区周围可见环形或弧形条状DWI高信号,ADC呈低信号。术后肌瘤消融区中央ADC值均增高,但b=500 s/mm2消融前后ADC值差异无统计学意义(P>0.05)。不同b值间,术前肌瘤及术后消融区中央部分,大b值较小b值所测ADC值数值低(P<0.01)。结论 3.0 T MRI弥散加权成像可以客观显示子宫肌瘤HIFU治疗后消融范围,并从分子水平反映子宫肌瘤及肌壁HIFU术后生理、病理改变。

Objective To use 3. 0 T MRI diffusion weighted imaging （ DWI） to evaluate the early efficiency of high-intensity focused ultrasound （HIFU） on uterine fibroids. Methods A total of 33 patients with uterine fibroids including 20 cases of solitary fibroids and 13 cases of multiple fibroids,with a total of 59 fibroids and patient＇s mean age being 34. 3 ± 8.7 years. All the patients underwent MRI scan,enhanced MRI scan,DWI scan before HIFU and on Id after HIFU to observe and calculate quantitatively the signal value of enhanced T1WI and ADC value, the maximum ablation area of uterine fibroid after HIFU, and to evaluate its therapeutic effects. Results There appeared nonperfusion low signal ablation zone in T1 enhanced scan sequence after HIFU in 59 uterine fibroids, with ablation rate being 70. 9%. After HIFU, the ablation zone displayed by DWI was closely correlated to that displayed by enhancement MRI scanning （ r = 0 .9 7 ） ,moreover, the circular or curved strip DWI high signal was found around the ablation zone in 35 uterine fibroids, with ADC showing low signal. After HIFU, the central ADC value in ablation zone of uterine fibroids was increased,but there was no significant difference in ADC value （ b = 500s/mm2） before and after ablation （ P 〉 0.05 ） . Among different b values, in ablation central part before and after operation, the ADC value of b = 1 500s/mm2 was obviously lower than that of b ： =500s/mm2 （ P 〈 0.01） . Conclusion The 3.0 T MRI diffusion weighted imaging can display objectively the ablation area of uterine fibroids before and after HIFU, which can reflect the physiological and pathological changes in the muscle wall of uterus and uterine fibroids after HIFU at molecular level.