实时谐波灰阶超声造影评价犬前列腺射频消融灶

Evaluation of the radiofrequency ablation lesions in canine prostate with real-time harmonic gray-scale contrast-enhanced ultrasonography

目的应用实时谐波灰阶超声造影技术观察实验犬前列腺射频消融灶,并与常规二维超声检查、彩色能量多普勒超声检查及病理学结果进行比较,以评估实时谐波灰阶超声造影评价前列腺射频消融灶的有效性。方法对5条犬前列腺两侧叶行射频消融,术后即刻行经直肠二维超声检查、能量多普勒超声检查和超声造影。超声造影下测量消融灶体积,并与病理学标本大体测量的结果相比较。结果常规二维超声在射频消融后即刻无法准确地观测消融灶的范围。彩色能量多普勒超声虽然不能准确评价消融灶的体积,但对消融灶的血流变化比较敏感,能及时反映消融灶血流状态的改变。超声造影则能准确评价消融灶的范围,其测量结果与病理学结果比较没有统计学差异,且超声造影能够实时观察消融灶内部及周边血流灌注的情况。结论常规二维超声和彩色能量多普勒超声能实时反映消融灶回声的变化和血流情况的改变。实时谐波灰阶超声造影技术能准确地评价前列腺射频消融灶的范围。

Objective To assess the radiofrequency ablation （RFA） lesions in canine prostate with real-time harmonic gray-scale contrast-enhanced ultrasonography and investigate the feasibility to predict these lesions. Methods A total of 5 male beagle dogs took RFA of the prostate. Radiofrequency （RF） was delivered under transrectal ultrasound （TRUS） guidance. A lesion was created in the right and left lateral lobes of canine prostate,respectively. The examination of conventional gray-scale ultrasonography,power Doppler ultrasonography,real-time harmonic gray-scale contrast-enhanced ultrasonography were performed immediately after RF procedure. All animals were subsequently sacrificed and the prostates were harvested for pathologic analysis. Thermal lesion volume was calculated based on expected shape of ellipsoid using equation. The volumes of the calculated thermal lesion on contrast-enhanced ultrasonography in dogs were compared with the volumes obtained from the pathological specimens. ResultsThe RFA lesions could not be imaged accurately with real-time conventional gray-scale or power Doppler ultrasonography. However,contrast-enhanced low MI perfusion imaging was able to have real-time monitoring for the lesion （no blood flow）. The volume of lesions was measured with contrast-enhanced ultrasonography without significant difference with those of pathologic results. Ultrasonic imaging（conventional gray-scale or power Doppler sonography）of the ablation areas also had its own characteristics. Conclusion The real-time harmonic gray-scale contrast-enhanced ultrasonography appears to be an accurate modality for assessment of RFA lesions. Conventional gray-scale and power Doppler sonography had their own characteristics to evaluate the RFA lesion.