犬前列腺射频消融灶实时谐波超声造影与MRI显像评价的比较研究

Evaluation of radiofrequency ablation lesions with Real-Time harmonic gray-scale contrast-enhanced ultrasonography and MR imaging in the prostate of canine

目的评估实时谐波灰阶超声造影及MRI显像评价前列腺射频消融灶的有效性,比较两种影像学方法的特点。方法对犬前列腺两侧叶行射频消融,术后即刻行经直肠常规超声检查、超声造影及MRI检查。超声造影及增强MRI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。结果射频消融后,增强MRI和超声造影均可以清晰地显示前列腺消融灶的范围,二者测量的消融灶体积与大体病理测量结果比较,差异没有统计学意义(P>0.05)。超声及MRI对前列腺消融灶的影像学表现的评价各具特点。结论增强MRI和实时谐波超声造影,均能够清晰反映前列腺射频消融灶的范围。二者各有优势,必要时应相互结合,以便更准确的评价前列腺射频消融的疗效。

Objective To compare Real-Time harmonic gray-scale contrast-enhanced ultrasonography and MR imaging in evaluation of radiofrequency（ RF） ablation lesions in prostate of canine. Methods Five male beagle dogs underw ent RF ablation of the prostate. RF w as delivered transrectally on the right and left lateral lobes of canine prostate w ith guidance of transrectal ultrasound（ TRUS）. Conventional gray-scale ultrasonography,pow er Doppler ultrasonography,Real-Time harmonic grayscale contrast-enhanced ultrasonography（ CEUS） and dynamic contrast-enhanced MR imaging（ DCEMRI） w ere performed immediately after RF ablation. All animals w ere sacrificed and the prostates w ere harvested for pathological examination. The volumes of thermal lesions on CEUS and DCE-MRI w ere calculated and compared w ith those on pathological specimens. Results DCE-MRI and CEUS accurately visualized and verified the area of coagulative necrosis as documented at histology. There w ere no statically significant differences betw een average lesion volume on DCE-MRI,CEUS and average lesion volume at histology. Ultrasonic imaging and MR imaging of the ablation areas also had their ow n characteristics. Conclusion Both DCE-MRI and CEUS can accurately assess the RF lesion of prostate and tw o imaging methods can be complemented each other in evaluation of the therapeutic effect of RFA.