中文摘要：

目的探讨PET/CT用于评估腹主动脉瘤（AAA）进展速度的价值及其机制。方法成年新西兰雄性大白兔30只，随机抽签分为两组，A组动脉瘤组（15只），B组高血压动脉瘤组（15只），均采用高浓度弹力蛋白酶（100IU/ml）在腔内灌注的方法制备肾下AAA模型。B组于手术成功后次日起持续以1000ng/（kg·min）速度泵注AngⅡ。监测血压，超声动态随访，观察血清单核细胞趋化蛋白（MCP-1）、基质金属蛋白酶（MMP9、MMP2），对比术后14d时PET/CT扫描平均标准化摄取值（SUVmean）结果。PET/CT后，两组各处死10只家兔，留取瘤体组织观察病理改变（HE、弹力纤维EVG、胶原纤维masson）及测定巨噬细胞（CD68）、基质金属蛋白酶（MMP9）。结果与A组比较，B组家兔血压明显升高，术后14d时动脉瘤增长速度明显快于A组，血清MMP9、MMP2，免疫组化CD68、MMP9结果均增加，差异有统计学意义（P＜0.01），而两组间血清MCP-1差异无统计学意义。病理结果显示A组动脉壁组织层次较为紊乱，弹力纤维变细、断裂、碎片及空泡形成，胶原纤维增多；B组动脉壁组织层紊乱，相比于A组弹力纤维断裂、破碎程度较重。PET/CT方面，相较于A组，B组瘤体部位SUVmean升高明显（P＜0.01），相关性分析显示SUVmean值与巨噬细胞阳性累积光密度值（IOD）（r=0.751，P＜0.01）及MMP9IOD（r=0.597，P＜0.05）呈正相关。结论PET/CT可以客观反映腹主动脉瘤局部炎症浸润状态，并可通过SUVmean值定性评估腹主动脉瘤的进展速度。

英文摘要：

Objective To explore the role of PET/CT in assessment of abdominal aortic aneurysm(AAA)progress.Methods We selected30New Zealand male rabbits,randomly classified them into2groups:the AAA group(group A,n=15)and the hypertension AAA group(group B,n=15).Both two groups are perfused with high elastic protease(100iu/ml)to establish AAA model.Group B is injected angiotensinⅡ(AngⅡ)sequentialy after the surgery.The boold pressure and development of AAA were monitored,Serum monocyte chemoattractant protein(MCP-1),matrix metalloproteinase(MMP9,MMP2)and mean standardized uptake value(SUVmean)of two week-PET/CT scans for both groups were analyzed.Pathological staining(HE,EVG and masson),CD68,MMP9through immunohistochemical were measured.Results Compared with group A,the blood pressure of rabbits in group B was significantly higher than that in group A.At14days postoperatively,the aneurysm growth rate in group B was significantly faster than that in group A.The levels of serum MMP9,MMP2,immunohistochemistry CD68and MMP9in group B were all increased,the difference was statistically significant(P<0.01).There was no significant difference in serum MCP-1between the two groups.Pathological results showed that the level of arterial wall tissue in group A was more turbulence,the elastic fibers were thinner,broken,fragmented and vacuolated,collagen fibers increased;the pathologic changes in group B were more serious.Compared with group A,the number of SUVmean in group B was significantly higher than that in group A(P<0.01).There was a positive correlation between SUVmean and macrophage positive density(IOD)(r=0.751,P<0.01)and MMP9IOD(r=0.597,P<0.05).Conclusions PET/CT can detect inflammatory infiltration of local lumen and assess the advance rate of AAA of AAA by SUVmean.