超声造影定量评估微波消融兔肝后凝固坏死范围:与病理所见对照

Contrast-enhanced ultrasound for evaluating area of coagulation necrosis after microwave ablation of rabbit liver:Comparison with pathological findings

目的与病理所见相对照,观察超声造影(CEUS)显示微波消融(MWA)兔肝后消融灶凝固坏死范围。方法将25只健康雄性实验兔随机平均分为L_(0)、M_(0)、H_(0)、M_(7)及M_(14)共5组,以不同功率、时间行MWA,之后通过CEUS及病理检查观察消融灶。L_(0)组:20 W、1 min,M_(0)组:30 W、1 min,H_(0)组:30 W、3 min,于每只兔肝消融4个靶区,均于消融当日观察消融灶;M_(7)组及M_(14)组均为30 W、1 min,于每只兔肝消融2个靶区,分别于第7及第14日观察消融灶。比较各组CEUS及病理所见消融灶或消融灶+水肿带(IRB)范围,观察其测值差异及随时间延长的变化。结果消融后第7日,CEUS显示M_(7)组消融灶面积略高于病理所见(校正P=0.045),但2种方法所测消融灶长径及短径差异均无统计学意义(校正P均>0.05);消融后第14日,2种方法所测M_(14)组消融灶长径、短径及面积差异均无统计学意义(校正P均>0.05)。CEUS或病理所见M_(0)组消融灶长径、短径及面积均小于M_(7)组及M_(14)组(校正P均<0.05),而M_(7)组和M_(14)组间差异均无统计学意义(校正P均>0.05)。结论以不同功率及时间消融兔肝当日,CEUS显示消融灶、消融灶+IRB范围及IRB面积均大于病理所见;消融后第7日CEUS与病理所见消融灶范围基本相符,提示于消融后第7日复查CEUS可准确判断消融灶实际凝固坏死范围。

Objective To observe area of coagulation necrosis after microwave ablation(MWA)of rabbit liver showed on contrast-enhanced ultrasound(CEUS)in comparison with pathological findings.Methods Twenty-five healthy male experimental rabbits were equally randomly divided into L_(0),M_(0),H_(0),M_(7)and M_(14)groups.MWA was achieved with different power and time,and then CEUS and pathological examinations were performed,respectively.Four target areas of rabbit liver were ablated under 20 W for 1 min in L_(0)group,under 30 W for 1 min in M_(0)group and under 30 W for 3 min in H_(0)group,and the ablated areas were observed on the same day after MWA,while 2 target areas of rabbit liver were ablated under 30 W for 1 min in M_(7)and M_(14)groups,and the ablated areas were observed 7 days and 14 days after MWA,respectively.The ablated foci and ablated foci+edema band(inflammatory reaction band,IRB)showed on CEUS and pathology were compared,and their differences and changes with time going were analyzed.Results On the day of ablation,the extent of ablation foci,ablation foci+IRB as well as IRB in L_(0),M_(0)and H_(0)groups showed on CEUS were all larger than pathological findings under light microscopy(all P<0.05),and the difference value of the length of the ablation foci between 2 methods increased sequentially among group L_(0),M_(0)and H_(0)(all adjusted P<0.05).Seven days after ablation,the area of ablation foci measured with CEUS in M_(7)group was slightly larger than that measured with pathology(adjusted P=0.045),but no significant difference of the length nor the short diameter was found(both adjusted P>0.05).Fourteen days after ablation,no significant difference of the length,the short diameter nor the area of ablation foci was detected between 2 methods in M_(14)group(all adjusted P>0.05).The length,short diameter and area of ablation foci in M_(0)group measured with CEUS or pathology were all smaller than those in M_(7)and M_(14)groups(all adjusted P<0.05),while no significant difference was found between the latter 2 groups(all adjusted P>0.05).Conclusion On the day of MWA of rabbit liver with different power and time settings,the areas of ablation foci,ablation foci+IRB and IRB showed on CEUS were larger than pathological findings.The range of ablation foci showed on CEUS 7 days after ablation was basically in line with pathology,indicating that CUES should be reexamined 7 days after ablation to evaluate the actual extent of coagulation and necrosis of ablation foci.