小b 值表观扩散系数图监测子宫肌瘤高能聚焦超声后疗效的价值

目的：探讨小 b值表观扩散系数图(ADC maps)监测子宫肌瘤高能聚焦超声(HIFU)术后消融灶的价值。方法收集25例共34个子宫肌瘤患者进行HIFU治疗,所有患者术前、术后24 h内均行常规MRI、CE-T1 WI及b值分别取150、600、1000 s/mm2的单指数扩散加权成像(DWI)检查。采用单因素方差分析分析各b值术前、术后消融灶和残留未消融灶的平均ADC值变化。对各b值的ADC伪彩图消融灶与增强MRI的吻合度进行分级评定。结果 b值为150 s/mm2时,术后消融灶平均ADC值[(1.48±0.27)×10-3 mm2/s]低于术前[(2.06±0.21)×10-3 mm2/s]及残留未消融灶平均ADC值[(1.98±0.23)×10-3 mm2/s](P<0.05)；b值为600、1000 s/mm2消融灶术前、术后ADC值以及残留未消融灶平均ADC值差异无统计学意义(P>0.05)。b值为150 s/mm2的ADC伪彩图消融灶与增强MRI的无灌注区域容积(non-perfused volume,NPV)有较高视觉吻合,优于 b 值为600、1000 s/mm2 ADC 图消融灶(P<0.05)。结论小b值(150 s/mm2)ADC图可间接反映子宫肌瘤HIFU治疗后的血供改变和消融范围,借此评估治疗效果。

The value of apparent diffusion coefficient map with low b-value to monitor the therapy of high-intensity focused ultrasonic for uterine fibroids

Objective To assess the value of apparent diffusion coefficient (ADC)map with low b-value to monitor the ablated tissue after high-intensity focused ultrasonic (HIFU)treatment for uterine fibroids.Methods 25 patients with 34 uterine fibroids were treated with HIFU.All patients underwent the routine MRI scans (including pre-and post-contrast scanning)and monoexponential model DWI with b values of 150,600 and 1 000 s/mm2 before the surgery and within 24 hours after the surgery.The mean ADC values with different b-values of the ablated and non-ablated tissues between pre-and post-treatment were analyzed by one-way ANOVA test.The consistency of the ablation area between ADC maps with different b-values and contrast enhancement MRI were evaluated. Results With the b-value of 150 s/mm2 ,the mean ADC value of the ablated tissue was (1.48±0.27)×10-3 mm2/s,which was less significantly than that of pre-treatment (2.06±0.21)×10-3 mm2/s and non-ablated tissue (1.98±0.23)×10-3 mm2/s (P<0.05). However,there were no significant differences in ADC values with the b values of 600 s/mm2 and 1 000 s/mm2 among those areas (P>0.05).A fine consistency of the ADC map with the low b-value (150 s/mm2 )was found with non-perfusion volume on contrast-enhanced T1 WI,which was superior to that with high b-values (600 s/mm2 and 1 000 s/mm2 )(P<0.05).Conclusion ADC map with low b-value (150 s/mm2 )can be used to evaluate the blood-supply changes and ablated volume of uterine fibroids indirectly,which helps to assess the treatment effect of HIFU.