胃癌中上腹部淋巴结转移的螺旋CT特征

摘要

Objective To evaluate the distribution of lymph nodes metastases(LNM) in upper and middle abdomen from primary gastric carcinoma and the imaging features of metastatic lymph nodes on contrast spiral CT scanning.Methods A retrospective study was performed.The study was consisted of 62 gastric carcinoma patients with upper and middle abdominal LNM identified by surgically and pathological procedure.All patients underwent CT scanning with intravenous contrast-enhancement on single-slice or 16-slice spiral CT.According to the LN location,upper and middle abdominal LN was classified as eight sites in this study as follows:porta hepatis,hepatoduodenal ligament,gastrohepatic ligament,gastrocolic ligament,gastrosplenic ligament,celiac,superior mesenteric and paraaortic area.Anatomic distribution and CT appearances of metastatic LN were observed.Results The incidence of LNM in each site from gastric carcinoma was:6.5 ％ (4/62)in porta hepatis,19.4％ (12/62)in hepatoduodenal ligament,79.0％ (49/62)in gastro hepatic ligament,30.6％ (19/62) in gastrocolic ligament,6.5％ (4/62) in gastrosplenic ligament,58.1％ (36/62) in celiac,24.2％(15/62) in superior mesenteric and 33.9％ (21/62) in paraaortic area,respectively.The gastrohepatic ligament (79.0％),celiac (58.1％),paraaortic (33.9％)and gastrocolic ligament(30.6％)lymph nodes were the common sites of LNM from primary gastric carcinoma.The MSAD(Maximum Short Axis Diameter) of metastatic LN varied from 1.1 to 5.3 cm.The density of most of metastatic nodes was hypo attenuation or iso-attenuation,and necrosis of metastatic LN was found in 71.3％ sites and occurred more frequently in metastatic LN with MSAD ≥ 2.5 cm.Necrosis of metastatic LN could be categorized as 3 types:no obvious necrosis (type 1,28.81％),the volume of necrosis region less than 1/2 in metastatic LN(type 2,30.0％) and the volume of necrosis region more than 1/2 in metastatic LN(type 3,41.3％).Conclusions The LNM of gastric carcinoma is distributed along the lymphatic drainage route of gastric area and associated with the location of tumor.The images of enhanced spiral CT scanning showed that the LNM are low density,edge blur,necrosis and partially visible fusion.%目的 探讨胃癌中上腹部淋巴结转移分布特点及其螺旋CT影像表现特征.方法 选取经病理或临床综合诊断为胃癌且有中上腹部淋巴结转移的患者62例,均经螺旋CT进行腹部增强扫描,重点对淋巴结转移的发生部位、大小、数目、形态、密度以及强化后表现等进行观察分析.结果 胃癌中上腹部淋巴结转移以肝胃韧带(79％)、腹腔动脉周围(58.1％)、腹主动脉周围(33.9％)及胃结肠韧带(30.6％)转移发生率较高.中上腹部共计160个部位发生淋巴结转移,每例发生淋巴结转移的部位数为1～7个,平均2.58个/例.转移性淋巴结的最大短轴径(MSAD)为1.1 ～5.3 cm,平均3.7 cm.共计有123个部位(71.3％)转移淋巴结中观察到较明显坏死,转移淋巴结≥2.5 cm较多见.结论 胃癌的中上腹部淋巴结转移分布主要沿胃的淋巴引流途径,与肿瘤在胃中所处位置有关.增强螺旋CT扫描转移淋巴结常呈等低密度,边缘多模糊,可发生坏死,部分可见融合.