结直肠癌双层探测器光谱CT成像:转移性与非转移性淋巴结的对照研究

Dual-layer detector spectral CT imaging technology in differential diagnosis of the matastatic and non-matastatic lymph nodes in patients with colorectal cancer

目的:探讨双层探测器光谱CT(DLCT)成像技术对结直肠癌转移性与非转移性淋巴结的鉴别诊断价值。方法:回顾性分析2019年12月-2020年11月在本院行腹部DLCT检查且经病理证实为结直肠癌的41例患者的病例资料。41例患者共纳入113枚局部淋巴结,其中经病理检查证实为转移性淋巴结40枚,非转移性淋巴结73枚。由两位放射科医师共同分析每枚淋巴结的DLCT图像,分别在动脉期和静脉期图像上测量淋巴结的碘浓度、有效原子序数及能谱曲线(40~100 keV)的斜率,比较转移性与非转移性淋巴结光谱参数值的差异,将有统计学差异的参数纳入Logistic回归方程,筛选出有鉴别诊断价值的参数,并采用ROC曲线分析其诊断效能。结果:转移性淋巴结的动、静脉双期碘浓度、有效原子序数及能谱曲线斜率均低于非转移性淋巴结(P<0.05)。动脉期的碘浓度和能谱曲线斜率为转移性淋巴结的独立预测因子,预测淋巴结转移的AUC分别为0.795和0.809,敏感度分别为0.704和0.778,特异度均为0.722。结论:DLCT定量参数对结直肠癌患者转移性与非转移性淋巴结的鉴别诊断具有一定价值,其中以动脉期能谱曲线斜率的诊断效能最高。

Objective:The aim of this study was to investigate the value of dual-layer detector spectral CT(DLCT)technology in differential diagnosis of the metastatic and non-metastatic lymph nodes in patients with colorectal cancer.Methods:The data of 41 patients with pathologically confirmed colorectal cancer who underwent abdominal DLCT examination from December 2019 to November 2020 in our hospital were retrospectively analyzed.In 41 patients,a total of 113 lymph nodes(40 metastatic and 73 non-metastatic confirmed by pathology)were included.The DLCT images of each lymph nodes were analyzed by two radiologists.Iodine concentration(IC),effective atomic number(eff-Z)and slope of spectral curve(λ)of arterial and venous phase were measured and compared between the two groups.The parameters with significant differences were further analyzed by the logistic regression analysis and receiver operator characteristic(ROC)curve.Results:The IC,eff-Z andλof meta-static lymph nodes on arterial and venous phase were lower than those of non-metastatic lymph nodes(P<0.05).The IC andλat arterial phase were independent predictors of metastatic lymph nodes,with AUC of 0.795 and 0.809,sensitivity of 0.704 and 0.778,and both specificity of 0.722.Conclusion:The quantitative DLCT parameters have certain value in differential diagnosis of metastatic and non-metastatic lymph nodes in patients with colorectal cancer,and theλof arterial phase has the highest diagnostic efficacy.