能谱CT多参数成像预测胃癌淋巴结转移的应用价值

Application value of spectral CT multi-parameter imaging in predicting gastric cancer lymph node metastasis

目的探讨能谱CT多参数成像预测胃癌淋巴结转移的应用价值。方法采用回顾性病例对照研究方法。收集2014年1月至2017年6月郑州大学第一附属医院收治的86例胃癌病人的临床病理资料;男53例,女33例;中位年龄为53岁,年龄范围为22~87岁。所有病人采用能谱CT行腹部常规平扫和能谱动静脉期增强扫描检查,在后处理工作站对平扫图像、动静脉期70 keV单能量图像、动静脉期碘基图像进行分析。观察指标:(1)胃癌淋巴结转移情况。(2)胃癌淋巴结转移影响因素分析。(3)特殊病例介绍。计数资料以绝对数表示。单因素分析采用χ^(2)检验或秩和检验。多因素分析采用Logistic回归模型。结果(1)胃癌淋巴结转移情况:86例病人中,64例伴淋巴结转移,22例无淋巴结转移。(2)胃癌淋巴结转移影响因素分析。单因素分析结果显示:肿瘤生长方式、肿瘤长径、瘤周脂肪浸润、动脉期CT值、静脉期CT值、静脉期碘基值是影响胃癌淋巴结转移的相关因素(χ^(2)=6.753,Z=-3.180,χ^(2)=7.649,Z=-2.051、-2.971、-2.547,P<0.05)。多因素分析结果显示:瘤周脂肪浸润,静脉期碘基值[>12且≤16(100μg/cm^(3))、>16(100μg/cm^(3))]是胃癌淋巴结转移的独立影响因素(优势比=13.154,3.761、7.583,95%可信区间为2.597~66.620,1.893~8.572、4.769~16.692,P<0.05)。(3)特殊病例介绍。病例1:男,46岁。术前能谱CT增强检查结果示胃窦占位性病变伴淋巴结肿大。能谱CT增强检查动脉期70 keV单能量和碘基图像,原发灶层面横断位图像显示胃窦部胃壁明显增厚,轻中度强化,浆膜面及周围脂肪间隙清晰,伴胃体小弯侧淋巴结肿大。能谱CT增强检查动脉期70 keV单能量和碘基图像,幽门下层面横断位图像显示幽门下淋巴结肿大。能谱CT增强检查静脉期70 keV单能量和碘基图像,原发灶层面横断位图像显示胃窦部病灶分层强化,黏膜面明显强化,病灶黏膜面高碘基值。CT检查诊断为胃窦部胃癌伴淋巴结转移,无浆膜面及瘤周脂肪浸润。术后组织病理学检查结果示胃窦部中分化腺癌,浸润至肌层,合并淋巴结转移。病例2:男,53岁。术前能谱CT增强检查结果示胃体小弯侧胃癌伴淋巴结肿大。能谱CT增强检查动脉期70 keV单能量和碘基图像,原发灶层面横断位图像显示胃体小弯侧胃壁不均匀增厚,中度强化,瘤周脂肪间隙模糊,浆膜面模糊,伴胃体小弯侧多发淋巴结肿大。能谱CT增强检查静脉期70 keV单能量横断位图像显示胃体小弯侧病灶,胃体小弯侧肿大淋巴结分界不清晰,瘤周脂肪间隙模糊。能谱CT增强检查动脉期70 keV单能量腹腔干层面横断位图像显示脾动脉旁淋巴结肿大,周边环形明显强化,中央坏死成分无强化。CT检查诊断为胃体小弯侧胃癌伴淋巴结转移,合并浆膜面侵犯及瘤周脂肪浸润。术后组织病理学检查结果示胃体小弯侧低分化腺癌,浸润至浆膜层,伴淋巴结转移。结论瘤周脂肪浸润、静脉期碘基值是胃癌淋巴结转移的独立影响因素。

Objective To investigate the application value of spectral computed tomo-graphy(CT)multi-parameter imaging in predicting gastric cancer lymph node metastasis.Methods The retrospective case-control study was conducted.The clinicopathological data of 86 patients with gastric cancer who were admitted to the First Affiliated Hospital of Zhengzhou University from January 2014 to June 2017 were collected.There were 53 males and 33 females,aged from 22 to 87 years,with a median age of 53 years.All patients received abdominal plain scan and arterial and venous phase contrast spectral scan.Images of plain scan,70 keV monochromatic and iodine-based images in arterial and venous phase were analyzed on post-processing working station.Observation indicators:(1)gastric cancer lymph node metastasis;(2)analysis of influencing factors for lymph node metastasis in gastric cancer;(3)introduction of special cases.Count data were described as absolute numbers.Univariate analysis was performed using the chi-square test or rank sum test.Multivariate analysis was conducted using the Logistic regression model.Results(1)Gastric cancer lymph node metastasis:of the 86 patients,64 cases had lymph nodes metastasis and 22 had no lymph nodes metastasis.(2)Analysis of influencing factors for lymph node metastasis in gastric cancer:results of univariate analysis showed that tumor growth pattern,tumor diameter,infiltration of peritumor fat,CT value in arterial phase,CT value in venous phase,iodine value in venous phase were related factors affecting lymph nodes metastasis in gastric cancer(χ^(2)=6.753,Z=-3.180,χ^(2)=7.649,Z=-2.051,-2.971,-2.547,P<0.05).Results of multivariate analysis showed that infiltration of peritumor fat and the iodine value in venous phase were greater than 12(100μg/cm3)and not greater than 16(100μg/cm^(3)),or greater than 16(100μg/cm^(3))were independent risk factors affecting lymph nodes metastasis in gastric cancer(odds ratio=13.154,3.761,7.583,95%confidence interval as 2.597-66.620,1.893-8.572,4.769-16.692,P<0.05).(3)Introduction of special cases:case 1 was male,aged 46 years.Results of preoperative spectral CT enhanced scan showed gastric antrum space occupying lesion combined with enlarged lymph nodes.During enhancement arterial phase,spectral CT 70 keV monochromatic images and corresponding iodine-based images of primary lesion layer in the transverse view showed gastric wall thickening with mild to moderate enhancement,clear fat space in serosa and enlarged lymph nodes in lesser curvature.The spectral CT 70 keV monochromatic images and corresponding iodine-based images below pylorus level in the transverse view showed subpyloric enlarged lymph nodes.During enhancement venous phase,the 70 keV monochromatic images and corresponding iodine-based images of primary lesion layer in the transverse view showed layered enhancement of gastric antrum lesions and mucosal enhancement,with a high iodine value.The patient was diagnosed as gastric antrum cancer with lymph node metastasis,no serosal or peritumoral fat invasion.Results of postoperative pathological examination showed moderately differentiated adenocarcinoma of gastric antrum with serosal invasion and lymph node metastasis.Case 2 was male,aged 53 years.Results of preoperative spectral CT enhanced scan showed gastric cancer of lesser curvature combined with enlarged lymph nodes.During enhancement arterial phase,70 keV monochromatic images and corresponding iodine-based images of primary lesion layer in the transverse view showed gastric wall heterogeneous thickening of lesser curvature,with moderate enhancement,obscure peritumor fat space,unclear serosa,and multiple enlarged lymph nodes in lesser curvature.During enhancement venous phase,70 keV monochromatic images in the transverse view showed unclear boundary between lesions and enlarged lymph nodes in lesser curvature,obscure peritumor fat.During enhancement arterial phase,70 keV monochromatic images of celiac trunk layer in the transverse view showed parasplenic artery lymph nodes,with circular enhancement and no enhancement in central necrotic elements.The patient was diagnosed as gastric cancer of lesser curvature with lymph node metastasis,serosal and peritumor fat invasion.Results of postoperative pathological examination showed poorly differentiated adenocarcinoma of gastric antrum with serosal invasion and lymph node metastasis.Conclusion The infiltration of peritumor fat and iodine value in venous phase are independent factors affecting gastric cancer lymph node metastasis.