摘要
目的比较经直肠超声造影与磁共振弥散加权成像(DWI-MR)检查评估前列腺射频消融术后短期效果的可靠性。方法对5只比格犬的前列腺两侧叶行射频消融,术后即刻行经直肠超声造影和磁共振成像(MRI)检查,MRI检查中以T2加权像(T2WI)作为定位像,构建弥散加权成像图和后续的表观弥散系数(ADC)图。比较经直肠超声造影和DWI-MR检查的影像学特点,并以病理学大体标本为标准,评估两种检查结果的准确性。结果所有犬均顺利完成射频消融术,并于术后立即完成相关的超声造影和MRI检查。射频消融操作过程中未发生出血、麻醉意外等。超声造影检查示造影剂微泡未进入射频消融灶内部,射频消融灶与周边正常前列腺组织分界清楚,并可见射频消融灶周边有造影剂的明显环状增强。MRI的T2WI检查示,射频部位呈现高低混杂信号,但射频消融灶范围较模糊,与周围前列腺正常组织区分略困难。DWI-MR检查示,射频消融灶呈现高信号,同时周围有明显的环形高信号围绕,与周围正常前列腺组织分界较清晰。中央区、环形带和周围正常前列腺组织的ADC值分别为(2.274±0.089)×10-3、(0.973±0.177)×10-3、(2.589±0.143)×10-3 mm2/s,两两比较差异均有统计学意义(P值均<0.05)。射频消融术后即刻超声造影、DWI-MR检查(分别测量仅中央区和含外周带的两个区域)和病理大体测量的射频消融灶体积分别为(1.26±0.41)、(0.98±0.49)、(1.24±0.37)和(1.27±0.52)mL,DWI-MR检查(仅中央区)测得的射频消融灶体积显著小于其他3种方法(P值均<0.05),其他3种方法测得的结果两两比较的差异均无统计学意义(P值均>0.05)。结论经直肠超声造影和DWI-MR检查均能反映前列腺射频消融术后短期内射频消融组织的变化特点,但前者操作更简便,且准确度高,适合作为首选方法。
Objective To compare contrast enhanced ultrasound with diffusion-weighted imaging magnetic resonance （DWI-MR） in assessment of early changes after radiofrequency ablation （RFA） in prostate in canine model. Methods Five male beagle dogs with lesions in the right and left lateral lobes of prostate underwent RFA. Contrast enhanced ultrasound and magnetic resonance imaging （MRI） were performed immediately after RFA. During the MRI examination, DWI and apparent diffusion coefficient （ADC） images were constructed based on the T2 weight image （T2WI）. Then all the animals were sacrificed and the prostates were harvested for pathologic analysis. Thermal lesion volumes were calculated with contrast-enhanced ultrasonography and DWI were compared with volumes obtained from pathological specimens. Results All canines successfully underwent the RFA procedure followed by contrast-enhanced ultrasonography and MRI examination. No complications, such as bleeding, anesthetic accident, occurred during RFA. Contrast enhanced ultrasonography accurately visualized and verified the area of coagulative necrosis as documented at histology. Meanwhile, an obvious high echo ring wasfound around the coagulated region. In MRI-T2WI, the RFA region showed diffused signal with indistinguished border line, which was not easy to be identified from normal tissues. In DWI-MR, the RPF region exhibited the high signal with a clear relatively high signal ring. The ADO were （2. 274 ± 0. 089） × 10^-3 , （0. 973 ± 0. 177） ×10^-3 , and （2.589±0. 143）× 10^-3 mm^2/s in RPF region, border line and normal tissue, respectively （all P〈0.05）. The volumes of RFA region were （ 1.26 ± 0.41 ）, （0.98 ± 0.49）, （ 1.24 ± 0.37）, and （ 1.2± 0.52） mL in contrast- enhanced ultrasonography, DWI-MR （without border ring）, DWI-MR （with border ring） and gross view, respectively. The volume of radiofrequency ablation in DWI-MR （without border ring） was significantly smaller than that in the other three examination results （all P〈0.05）. There were no significant differences in average lesion volume between contrast-enhanced ultrasound, gross view or DWI-MR （with border ring, all P〉~ 0. 05）. Conclusion Both contrast-enhanced ultrasonography and DWl can be used to assess the RF lesion of prostate in early phase. However, it seems that the image obtained from contrast-enhanced ultrasound is more accurate than that obtained from DWI. Enhanced contrast ultrasound may be the first choice in evaluating radiofrequency ablation in early phase.
出处
《上海医学》
CAS
CSCD
北大核心
2014年第10期876-879,F0002,共5页
Shanghai Medical Journal
基金
上海市卫生局基金资助项目(20114167)
关键词
前列腺
射频消融
超声造影
磁共振弥散加权成像
评估
Prostate
Radiofrequency ablation
Contrast enhanced ultrasound
Diffusion-weighted imagingmagnetic resonance
Evaluation
