目的:分析比较胃黏膜相关淋巴组织(MALT)淋巴瘤患者n 18F-脱氧葡萄糖(FDG)PET/CT影像学特点和消化内镜分型，并评估病灶最大标准摄取值(SUVn max)反映肿瘤增殖活性及判断存在弥漫性大B细胞转化成分的价值。n 方法:回顾性比较分析2012年12月至2019年1月间南京鼓楼医院36例[男19例、女17例，年龄(46.4±18.1)岁]未经治疗、病理确诊为胃MALT淋巴瘤患者的n 18F-FDG PET/CT及消化内镜资料(分为慢性胃炎样型、凹陷型和隆起型)。通过目测法判断病灶为阳性(FDG摄取高于周围组织)或阴性(FDG摄取低于周围组织)，摄取方式分为局限性和弥漫性，勾画病灶感兴趣区，记录SUVn max，并采用单因素方差分析及最小显著差异n t检验对3种类型病灶SUVn max进行比较，采用Mann-Whitney n U检验对发生弥漫性大B细胞转化与非转化病灶的SUVn max进行比较。采用Spearman秩相关分析SUVn max与细胞增殖核抗原Ki-67间的相关性，并通过受试者工作特征(ROC)曲线分析获得SUVn max判断病灶存在弥漫性大B细胞转化成分的阈值。n 结果:PET/CT阳性者15例，诊断准确性为41.7%(15/36)，其中，对消化内镜分型为慢性胃炎样型的诊断准确性最低(4/16)，凹陷型次之(6/15)，而隆起型病灶最高(5/5)并多以局限性为主(4/5)。隆起型病灶SUVn max(10.7±6.4)明显高于慢性胃炎样型(2.1±0.8)和凹陷型(2.7±1.4)；n F＝13.010，均n P<0.05)。36例患者的病灶SUVn max[2.7(1.8, 5.0)]与Ki-67指数[10%(15%, 40%)]呈正相关(n rs＝0.345，n P＝0.039)。存在弥漫性大B细胞转化成分病灶的SUVn max明显高于不存在弥漫性大B细胞转化成分的病灶[9.4(3.1，14.8)与2.3(1.7，3.9)；n z＝-3.044，n P＝0.002]，且SUVn max判断存在弥漫性大B细胞转化成分的阈值为6.5(曲线下面积为0.788，n P＝0.011)。n 结论:18F-FDG PET/CT在诊断隆起型病灶上优势明显，但对慢性胃炎样型及凹陷型效能欠佳。SUVn max可用于辅助判断胃MALT淋巴瘤增殖活性及是否存在弥漫性大B细胞转化成分。n “,”Objective:To investigate n 18F-fluorodeoxyglucose (FDG) PET/CT imaging manifestations and digestive endoscopy of gastric mucosa-associated lymphoid tissue (MALT) lymphoma and evaluate whether maximum standardized uptake value (SUVn max) can reflect the tumor proliferation activity and diagnose the diffuse large B cell transformation.n Methods:18F-FDG PET/CT of 36 untreated histologically confirmed gastric MALT lymphoma patients (19 males, 17 females, age (46.4±18.1) years) between December 2012 and January 2019 in Nanjing Drum Tower Hospital were reviewed retrospectively. A positive or negative PET was defined based on visual analysis. n 18F-FDG uptake above surrounding tissues in the regions of interest defined by the nuclear physician was considered positive, while negative was definited if the n 18F-FDG uptake below surrounding tissues. Types of uptake included focal uptake and diffuse uptake. The characteristic findings of n 18F-FDG PET/CT and digestive endoscopy (3 types: chronic gastritis-like type, depressed type and protruding type) in the consecutive patients were evaluated. The region of interest was drawn and the maximum standardized uptake value (SUVn max) was measured. One-way analysis of variance and the least siginficant difference n t test were used to compare the SUVn max of 3 types of lesions and Mann-Whitney n U test was used for comparison of SUVn max between lesions with/without diffuse large B cell transformation. The correlation between SUVn max and Ki-67 was assessed by Spearman rank correlation analysis. Receiver operating characteristic (ROC) curve analysis was performed to calculate the optimal cut-off value for the diagnosis of diffuse large B cell transformation.n Results:Positive n 18F-FDG PET/CT were found in 15 patients and the diagnostic accuracy was 41.7%(15/36). n 18F-FDG uptake results were positive for all protruding tumors (5/5) mainly with focal uptake (4/5), but only 4/16 for chronic gastritis-like type tumors and 6/15 for depressed type tumors. SUVn max of protruding type tumors (10.7±6.4) was significantly higher than chronic gastritis-like type tumors (2.1±0.8) and depressed type tumors (2.7±1.4; n F=13.010, all n P<0.05). SUVn max (2.7(1.8, 5.0)) was associated with Ki-67 (10%(15%, 40%); n rs=0.345, n P=0.039). SUVn max of tumors with diffuse large B cell transformation in 36 patients was significantly higher than that with no transformation (9.4(3.1, 14.8) n vs 2.3(1.7, 3.9); n z=-3.044, n P=0.002), and the cut-off value of SUVn max was 6.5 (area under the curve: 0.788, n P=0.011).n Conclusions:18F-FDG PET may be a useful method for evaluating protruding type gastric MALT lymphoma but not appropriate for chronic gastritis-like type or depressed type tumors. SUVn max may be a useful biomarker for tumor proliferation activity and can be used for diffuse large B cell transformation diagnosis in gastric MALT lymphoma patients.n