【摘要】 目的探讨45～60℃高温不同作用时间对活体猪肝脏、胰腺组织的损伤效果及高强度聚焦超声(HIFU)焦域理想温度段及作用时间。方法选用普通杂种猪10头,根据焦域加温温度不同分为4个实验组(每组2头),以多极射频为加热源,在活猪肝及胰腺采用(45±1)℃、(50±1)℃、(55±1)℃、(60±1)℃等4种温度进行加热,分别持续作用15、30、60、90及120s,实验结束即刻和3d后,在普通光镜下及电子显微镜下观察加热区肝及胰腺组织细胞形态学变化,并与对照组(2头,未加温)正常肝及胰腺组织对照观察。结果(45±1)℃温度作用时间为15～120s,即刻观察肝及胰腺细胞,光镜下显示肝及胰腺细胞形态无明显变化;作用时间60s超微电镜下可见细胞器肿胀,但细胞结构完整;(50±1)℃作用15s即刻观察,光镜下见细胞明显肿胀,电镜下见细胞空泡样变性、线粒体和内质网明显损害;3d后光镜下观察,肝及胰腺组织中出现片状凝固性坏死,电镜下见细胞结构明显破坏。55～60℃持续作用15s以上各加温组即刻取材的肝及胰腺组织光镜下均可见凝固性坏死。结论55～60℃持续作用15s可能是HIFU焦域理想温度段及作用时间。更多还原

【Abstract】 Objective To evaluate the damage degree of pig’s liver and pancreas at 45℃-60℃ within different durations in vivo,then identify the optimal temperature latitude and duration within the focal region target by high intensity focused ultrasound.Methods The liver and pancreas of pigs were exposed in vivo to defined temperatures of 45±1℃、50±1℃、55±1℃、60±1℃ for varying durations of 15,30,60,90 or 120 seconds using a radio-frequency ablation probe.Exposed tissue was obtained immediately following treatment or on day 3 following exposure.Histopathologic evaluation was performed using light microscopy,transmission electron microscopy.Results Pancreas and liver exposed to 45±1℃ for 15-60 seconds,demonstrated no discernable changes immediately following treatment by light microscopy.Transmission electron microscopy performed on tissue exposed for 60 seconds showed cell organ swelling without rupture.At 50±1℃ for 15 seconds,light microscopy immediately showed obvious cell swelling and electron microscopy showed breakdown of mitochondria membrane and endocytoplasmic reticulum.On day 3 there was evidence of coagulative necrosis by light microscopy.Tissue exposed to 55-60℃ for 15 seconds demonstrated coagulative necrosis by light microscopy performed on tissue obtained immediately following treatment.Conclusions The temperature of 55-60℃ for 15 seconds may be the optimal temperature and duration within the focal region of HIFU.更多还原