磁共振成像DWI序列可代替增强扫描评估高强度聚焦超声治疗子宫腺肌症的即时消融效果

Diffusion-weighted magnetic resonance imaging instead of contrast-enhanced imaging for evaluating immediate therapeutic efficacy of high-intensity focused ultrasound ablation of adenomyosis

目的探讨磁共振成像DWI序列在评估高强度聚焦超声(HIFU)治疗子宫腺肌症即时消融效果中代替增强扫描的可行性。方法回顾性分析2017年12月~2020年7月在南方医科大学附属佛山妇幼保健院就诊的29例子宫腺肌症患者资料,平均年龄40.5±5.4岁,均于HIFU术前及术后24 h内行MRI检查。由两名观察者独立评估DWI图像上消融灶的形态,分为1型:斑点状或无信号改变,2型:斑片状,3型:环状,通过kappa检验法评估DWI图像上消融灶形态分型的观察者间、观察者内一致性。在DWI图像上测量2型及3型消融灶的消融坏死区体积,通过Bland-Altman法评估DWI与增强扫描图像上测量消融坏死区体积的一致性、DWI图像上测量消融坏死区体积的观察者间、观察者内的可靠性。结果29个消融坏死区,体积为36.9(16.4,65.6)cm3,在DWI上24~25个(82.8%~86.2%)消融灶为可测量的2、3型。在DWI图像,消融灶形态分型的观察者间及观察者内一致性的kappa值分别为0.798(P=0.000)、0.933(P=0.000)。Bland-Altman图显示,DWI与增强扫描图像上测量消融坏死区体积的一致性、DWI图像上测量消融坏死区体积的观察者间、观察者内的可靠性均为良好,均仅有一个点在95%一致性界限范围之外。4~5个无法在DWI图像上测量的1型消融灶的体积较小,最大者仅为18.61 cm3,消融治疗效果欠佳。结论通过对消融坏死区形态评估、体积测量,DWI序列可评估子宫肌腺症HIFU治疗的即时消融效果,代替增强扫描。

Objective To explore the feasibility of diffusion-weighted magnetic resonance imaging(DWI)instead of contrast-enhanced(CE)imaging for evaluation of the immediate therapeutic efficacy of high-intensity focused ultrasound(HIFU)ablation for treatment of adenomyosis.Methods We retrospectively analyzed the data of 29 patients aged 40.5±5.4 years under going HIFU treatment for adenomyosis in our hospital between December,2017 and July,2020.The patients received MRI examination both before and within 24 h after the operation.Two observers analyzed the morphology of the ablation area on DWI and classified the lesions into type 1(spot-like or no obvious signal intensity changes),type 2(patchy signal intensity changes)and type 3(ring-like signal intensity changes).The inter-and intra-observer reliability of morphological assessment was assessed using kappa test.The volume of necrotic tissues following the ablation was measured with both DWI and CE imaging,and the consistency of the measurements and the inter-and intra-observer reliability of DWI-based measurements were evaluated using Bland-Altman plot tests.Results The median volume of necrotic tissues was 36.9 cm3(range 16.4-65.5 cm3)following ablation of the 29 lesions.DWI findings identified 24-25(82.8%-86.2%)lesions with type 2 or 3 signal changes following the ablation with measurable necrotic tissue volume.On DW images,the Kappa value of intra-and inter-observer reliability for morphological classification of the ablation area reached 0.798(P=0.000)and 0.933(P=0.000),respectively.Bland-Altman plots showed a good consistency of the necrotic volumes measured by CE and at DWI with a strong inter-and intra-observer reliability of DWI-based volume measurements(with only one point outside the range of 95%limits of agreement).The remaining 4 or 5 lesions,which presented with type 1 signal changes following ablation,were all small in size(the largest was only 18.61 cm3)and showed poor therapeutic responses to the ablation.Conclusion DWI-based morphological assessment and necrotic tissue volume measurement can replace CE imaging for assessment of the immediate therapeutic efficacy of HIFU ablation for treatment of adenomyosis.