目的:分析胃肠道间质瘤(GIST)肝转移灶n 18F-脱氧葡萄糖(FDG)PET/CT显像特点，以提高诊断准确性。n 方法:回顾性分析2013年5月至2019年7月间在福建省肿瘤医院行n 18F-FDG PET/CT检查并确诊肝转移的33例GIST患者(男18例，女15例，年龄34～70岁)的临床和影像资料。患者均行n 18F-FDG PET/CT早期显像，另有9例后行延迟显像。对患者PET/CT图像行视觉分析，比较病灶与肝本底的放射性摄取，将转移灶分为高代谢、稍高代谢、等或低代谢；计算并比较GIST原发灶与肝转移灶的最大标准摄取值(SUVn max)，另分析两者的关系。采用Wilcoxon秩和检验和Spearman秩相关分析数据。n 结果:33例GIST的肝转移患者中，肝转移单发9例，多发24例，共104个病灶。104个肝转移病灶直径为0.8～14.6[2.2(1.5，3.9)] cm，SUVn max为1.4～21.5[3.6(2.4，5.7)]。94.2%(98/104)的病灶边界清楚；65.4%(68/104)的病灶密度均匀(其中2个囊性病灶)，34.6%(36/104)的病灶密度不均匀，可见出血、囊变或坏死。PET图像视觉分析中，38.4%(40/104)的病灶为高代谢，26.0%(27/104)的病灶为稍高代谢，35.6%(37/104)的病灶为等或低代谢。24例多发肝转移患者中，79.2%(19/24)同时存在不同代谢水平的病灶。67个代谢增高病灶中，34.3%(23/67)呈均匀代谢，其中13个病灶直径<2.0 cm；65.7%(44/67)呈不均匀代谢，其中36个病灶直径≥2.0 cm。15例GIST同时性肝转移患者的原发灶与肝转移灶SUVn max[9.2(6.8，14.5)与3.8(2.1，6.0)]间呈中等程度相关(n rs＝0.556，n P<0.01)；两者差异有统计学意义(n z＝-5.098，n P<0.01)。延迟显像中，13/15的等或低代谢肝转移病灶转为稍高代谢。n 结论:GIST肝转移n 18F-FDG PET/CT显像通常边界清楚，常合并囊变、出血或坏死；代谢表现多样；延迟显像有助于低代谢GIST肝转移病灶的诊断。n “,”Objective:To analyze the imaging features of hepatic metastases in gastrointestinal stromal tumors (GIST) on n 18F-fluorodexyglucose (FDG) PET/CT in order to improve the accuracy of diagnosis.n Methods:Clinical and imaging data of 33 patients (18 males, 15 females, age 34-70 years) with hepatic metastases in GIST who underwent PET/CT examination between May 2013 and July 2019 in Fujian Cancer Hospital were analyzed retrospectively. All patients underwent n 18F-FDG PET/CT early imaging, and nine of them underwent delayed imaging. Visual analysis was performed on the PET/CT images by comparing FDG uptake of hepatic lesions and liver background, and all lesions were classified as significant hypermetabolism, slightly higher metabolism and equal or lower metabolism. Maximum standardized uptake value (SUVn max) of primary GIST lesions and hepatic metastases were calculated and compared, and the relationship between them was analyzed. Wilcoxon rank sum test and Spearman rank correlation analysis were used to analyze the data.n Results:Among 33 GIST patients, 9 patients had solitary hepatic metastasis, and 24 patients had multiple hepatic metastases (104 lesions). The diameter of metastases was 0.8-14.6(2.2(1.5, 3.9)) cm, and SUVn max was 1.4-21.5(3.6(2.4, 5.7)). Of the 104 hepatic metastases, 94.2%(98/104) lesions had clear boundaries, 65.4%(68/104) lesions had uniform density (2 lesions with cystic density), 34.6%(36/104) lesions had uneven density in which hemorrhage, cystic change or necrosis could be found. On visual analysis of PET images, 38.5%(40/104) lesions were with significant hypermetabolism, 26.0%(27/104) were with slightly higher metabolism and 35.6%(37/104) were with equal or lower metabolism. In 24 patients with multiple hepatic metastases, 79.2%(19/24) showed different metabolic levels synchronously. Among 67 hypermetabolic metastases, 34.3%(23/67) were with homogeneous metabolism, of which 13 lesions with diameter<2.0 cm; 65.7%(44/67) were with heterogeneous metabolism, of which 36 lesions with diameter≥2.0 cm. There was a moderate correlation of SUVn max between GIST primary tumors and hepatic metastases (n n=15; 9.2(6.8, 14.5) n vs 3.8(2.1, 6.0), n rs=0.556, n P<0.01). The difference of SUVn max between GIST primary tumors and hepatic metastases was statistically significant (n z=-5.098, n P<0.01). In delayed imaging, 13/15 hepatic metastases with equal or lower metabolism changed to slightly higher metabolism.n Conclusions:Hepatic metastases in GIST on n 18F-FDG PET/CT imaging usually have clear boundary, and often associate with cystic degeneration, hemorrhage or necrosis. The metabolic patterns of hepatic metastases in GIST are varied. Delayed PET/CT imaging is helpful for the diagnosis of hypometabolic hepatic metastases in GIST.n