自身免疫性胰腺炎的18F-FDG PET/CT影像学特点

18F-FDG PET/CT findings of autoimmune pancreatitis

目的 探讨18F-FDG PET/CT在自身免疫性胰腺炎(AIP)诊断中的影像学特点及应用价值.方法 回顾性分析2005年至2012年6例AIP患者[均为男性,51～78(平均69)岁]治疗前的18 F-FDG PET/CT影像学特征(其中2例具备激素治疗前后的PET/CT影像资料).目测分析判定胰腺形态异常,并以肝脏为标准对胰腺放射性摄取进行评分(高于肝脏为3分,与肝脏近似为2分,低于肝脏为1分).半定量分析测定常规及延迟显像的胰腺SUV,并采用SPSS 17.0软件将延迟显像前后的SUV进行配对t检验.结果 6例AIP患者胰腺均表现为弥漫性增大,放射性摄取均呈弥漫斑片状分布,其中5例为3分,1例为2分,SUVmax3.2～6.0(5.2±1.1);5例延迟显像中,4例SUVmax增高,1例保持不变,延迟后SUVmax5.3～7.2,延迟显像前后SUVmax差异无统计学意义(4.8～6.0:t =-2.424,P＞0.05).5例出现胰腺外异常摄取,以颌下腺为著.2例治疗后显像者其胰腺均缩小,胰腺及胰腺外摄取灶SUV恢复正常.结论 18F-FDG PET/CT能够反映AIP胰腺和胰腺外代谢活性异常及治疗前后的病灶代谢变化,有助于AIP的诊断、鉴别诊断及疗效评价.

Objective To investigate the image characteristics and clinical application of 18F-FDG PET/CT in autoimmune pancreatitis (ALP).Methods The PET/CT images from six male patients (age ranging from 51 to 78(average 69) years) with AIP from 2005 to 2012 were studied retrospectively.Of the six patients,two had follow-up PET/CT images after steroid therapy.The morphologic abnormality was visually analyzed and SUV was calculated.Scores were obtained according to the SUV of pancreas compared with that of the liver (3 =SUV higher than liver,2=SUV similar to liver,1 =SUV lower than liver).The difference between the regular and delayed SUV was compared by paired t test using SPSS 17.0.Results All of the 6 patients showed diffuse FDG uptake in the entire pancreas with SUVmax of 3.2-6.0(5.2± 1.1).Five patients had score 3 and one had score 2.Five patients had delayed scan,of which 4 had increased uptake (SUVmax5.3-7.2),but the SUVmax was not significantly different compared to that before delay scan (4.8-6.0,t =-2.424,P＞0.05).Five patients showed extrapancreatic uptake,especially in the salivary glands.After the steroid therapy,the enlarged pancreas reduced and the intense uptake of the pancreas disappeared.The extrapancreatic uptake showed coinstantaneous remission.Conclusions Increasing FDG uptake at entire pancreas was observed in patients with AIP.18F-FDG PET/CT may be useful for detecting AIP and the associated extrapancreatic uptake,and monitoring the change after therapy,yet it needs further evaluation.