中文摘要：

目的 探讨多参数MRI（Mp-MRI）在前列腺癌（PCa）氩氦刀冷冻消融术后评估消融切缘的价值.方法 回顾性分析经穿刺病理确诊为PCa后行氩氦刀冷冻治疗,且在治疗后行3.0 TMp-MRI检查的13例患者.患者均行前列腺及精囊常规MRI、DWI和灌注加权成像（PWI）检查.观察冷冻后切缘信号特征,测量冷冻消融中心的ADC值.对T2WI、DWI、PWI序列图像PCa冷冻术后切缘进行评分,并采用非参数秩和检验进行比较.结果 9例T2WI切缘呈高或稍高信号,消融切缘清晰.DWI消融切缘2例清晰,残腔中心ADC值为（0.644±0.121）×10^-3 s/mm^2.PWI 12例切缘清晰,切缘动脉早期均呈强化高信号.采用T2WI、DWI、PWI对术后消融切缘的评分中位数分别为4（2-5）、3（2-4）、5（3-5）分,差异有统计学意义（H=0.602,P=0.022）,两两比较差异均有统计学意义（P均＜0.05）.结论Mp-MRI在PCa氩氦刀冷冻治疗术后评估切缘具有一定价值,PWI较DWI、T2WI可以更好地显示PCa切缘.

英文摘要：

Objective To investigate the delineation and visualization of the margin of ablation for prostate cancer in multi-parametric MRI （Mp-MRI） of prostate cancer argon-helium cryosurgery.Methods Thirteen patients with suspected prostate cancer underwent Mp-MRI at a 3.0 T MR before and within one week to three months after cryosurgery.The delineation and visualization of the margin of ablation for prostate cancer in T2WI,DWI and perfusion weighted imaging （PWI） had been prospectively interpreted by 2 radiologists.ADC value was recoded in the middle of the ablation for prostate cancer.Comparisons between T2WI,DWI,PWI were evaluated using the Kruskal-Wallis test and Mann-Whitney test.Results Of the 13 cases,the margin of ablation for prostate cancer were clearly delineated in 9 on T2WI,2 on DWI and 12 on PWI.ADC value was （0.644±0.121）×10^-3 s/mm^2.In the delineation and visualization of the margin of ablation for prostate cancer,the grade were 4（2 to 5）,3（2 to 4） and 5（3 to 5）in T2WI,DWI and PWI,there was significant difference among them（H=0.602,P=0.022）,and there were significant difference between them （P〈0.05）.Conclusions Mp-MRI provides a powerful tool for noninvasive evaluation of frozen tissue created by focal cryoablation of prostate cancer.PWI is significantly superior to T2WI and DWI in the delineation and visualization of the margin of ablation for prostate cancer.