肾上腺皮质癌的CT、MRI及PET/CT表现

CT,MRI and PET/CT features of adrenocortical carcinoma

目的探讨肾上腺皮质癌(ACC)的CT、MRI及^(18)F-FDG PET/CT影像学特征。方法回顾性分析经病理证实的21例ACC患者的影像学资料。CT增强扫描16例、MRI增强扫描8例、PET/CT扫描4例,分析其影像学表现。结果1)20例肿瘤单发(左侧13例、右侧7例),1例为双侧发病;直径为(10.9±3.0)cm;16例肿瘤呈分叶状,5例呈类圆形;2)CT表现:15例(15/17)平扫密度不均,2例均匀;瘤内钙化5例。16例整体呈渐进性强化方式;瘤内见血管影13例,瘤内见星芒状无明显强化区6例;假性厚壁囊肿样表现4例,内壁见壁结节样改变;边缘见包膜结构10例,呈延迟强化;3)MRI表现:8例呈T_1WI稍低、T_2WI稍高的混杂信号,DWI高信号;瘤内可见囊变5例、出血7例、瘢痕组织6例、脂质成分2例。强化方式与CT检查基本相同,对比剂扩清延迟;边缘见包膜结构6例,瘤内瘢痕组织延迟强化2例;4)PET/CT表现:4例呈FDG不均匀摄取增高,高摄取区与增强CT强化区一致,SUVmax为(7.5±4.7),假性厚壁囊肿样表现1例。结论ACC有一定的影像学特征,CT、MRI和PET/CT检查在诊断中各有优势,联合应用有助于全面反映肿瘤的病理特征。

Objective To investigate the CT, MRI and 18 F-FDG PET/CT features of adrenocortical carcinoma （ACC）. Methods Imaging data of 21 ACC patients confirmed by histopathology were retrospectively studied. There were 16 patients with enhanced CT, and 8 cases with enhanced MRI, and 18 F-FDG PET/CT was performed in 4 cases, and the imaging findings were analyzed. Results 1） Single lesion was found in 20 patients （13 cases on the left and 7 cases on the right）, and bilateral side lesions in one patient. The diameters of the lesions were about （10.9±3.0） cm, and the shape was lobulated in 16 cases, round-like in 5 cases; 2） CT findings： on plain CT, 15 （15/17） cases showed inhomogeneous density, 2 cases showed homogeneous density and intratumoral calcification was found in 5 cases. On enhanced CT, progressive enhancement was shown of all the 16 cases. 13 cases showed intratumoral vascular shadow, 6 cases showed no obvious enhancement area within the tumor; 4 cases manifested pseudo thickness cyst with wall nodular change; marginal envelope structure was shown in 10 cases with delayed enhancement; 3） MRI findings： T 1WI showed slightly lower signal and T 2WI showed slightly higher medley signal in 8 cases, DWI showed higher signal. There were 5 cases of cystic invasion, 7 cases of hemorrhage, 6 cases of scar tissue and 2 cases of lipid composition. The MRI enhanced pattern was similar as CT, manifested as a delayed enhancement. Marginal envelope structure was showed in 6 cases, scar tissue in tumor showed a delayed enhancement in 2 cases; 4） PET/CT findings： inhomogeneous high uptake was showed in 4 cases, and the high uptake region was consistent with the CT enhancement region, the SUVmax was about （7.5±4.7）, 1 case manifested pseudo thickness cyst. Conclusion ACC shows some imaging characteristics. CT, MRI or PET/CT has each advantages in diagnosis, and the combined application is helpful to reflect the pathological features of ACC.