超声造影在脑组织微波消融中的实验研究

Experimental study of contrast-enhanced ultrasonography on microwave ablation for brain tissue

目的探讨超声造影在评价动物脑组织微波消融中的应用价值，为临床应用提供实验依据。方法选取健康家犬17只，以不同微波功率及消融时间组合分别作用于动物脑组织；术后30min去骨瓣，分别行常规超声及超声造影检查，观察消融灶的边界、范围，比较消融灶内、水肿带区、正常脑组织内的超声造影时间一强度曲线及参数；术后5h取出脑组织，观察消融灶的大体病理及显微病理改变。结果①脑组织微波消融成功获得34个消融灶，超声造影所测消融灶范围较常规超声测值小，差异有统计学意义（P=0．000）；病理证实超声造影所显示的消融坏死范围更为准确，超声造影无增强区的脑组织完全坏死，常规超声与超声造影所测消融灶范围之间的环形区域为水肿带。②水肿区与正常脑组织的超声造影开始增强时间、达峰时间及峰值强度比较，差异无统计学意义（P值分别为0．992、0．993、0．749）。结论超声造影能实时准确显示脑组织微波消融的坏死范围，并能显示消融灶及周围脑组织的血流灌注情况，可用于评价脑组织微波消融的效果。

Objective To explore the value of contrast-enhanced ultrasound（CEUS） in microwave ablation for brain tissues,and to provide experimental evidences for clinical application. Methods A total of 17 domestic dog brains underwent microwave ablation randomly at different output power and ablation duration. Ablation lesions were detected by conventional ultrasonography（US） and CEUS in half an hour after MA,the boundary and size of lesions were observed, then the morphology and parameters of timeintensity curve were compared among ablation area, edema area and normal area. Five hours after ablation, brain tissues were took out, morphology and microscope structure changes were observed. Results （1） Thirty-four lesions were obtained after microwave ablation. By contrast with US, the size measured by CEUS was smaller, the difference was statistical（ P = 0. 000）. The size measured by CEUS proved to be accurate in the results of microscope pathology, and the brain lesions were necrosis completely in no enhancement area. （2）The parameters of time-intensity curve between edema zone and normal brain had no statistical difference（ P = 0. 992,0. 993,0. 749）, respectively. Conclusions The boundary of necrotic lesions was showed accurately in CEUS, meanwhile the perfusion of ablation zone and surrounding brain could be displayed clearly. CEUS could be used to assess the effect of microwave ablation.