Abstract：
OBJECTIVE: To investigate the diagnostic ability of novel spectral CT-derived parameters for gastric cancer histological types and Ki-67 expression.
METHODS: A total of 72 patients with histologically proven gastric cancer (GC) were retrospectively included in this study. All patients underwent dual-phase enhanced abdominal spectral CT. The arterial (AP) and venous phase (VP) slope of the spectral curve (λHU), iodine concentration (IC), normalized IC (NIC), effective atomic number (Zeff) and iodine-no-water concentration were retrospectively compared between patients with low and high Ki-67 expression levels and with different histological types in GC patients. The ROI was outlined independently by two senior physicians, and the average of three measurements at the largest level was taken. In addition, interobserver reproducibility was assessed by Bland-Altman analysis. Correlations between quantitative parameters and Ki-67 expression levels were assessed by Spearman\'s correlation coefficients.
RESULTS: The values between the mucinous group and nonmucinous carcinoma group were significantly different in both phases. The IC, NIC, and iodine-no-water concentration in the VP were significantly different among the Ki-67_L, Ki-67_M, and Ki-67_H groups. Spearman rank correlation analysis demonstrated a positive correlation between Ki-67 expression levels and IC, NIC, and iodine-no-water concentration in the VP, with correlation coefficients of 0.304, 0.424, and 0.322, respectively.
CONCLUSIONS: Quantitative spectral parameters can discriminate between low and high Ki-67 expression and different histological types in GC. The NIC, IC and iodine-no-water concentration can be useful parameters for evaluating of Ki-67 expression levels.
METHODS: A total of 72 patients with histologically proven gastric cancer (GC) were retrospectively included in this study. All patients underwent dual-phase enhanced abdominal spectral CT. The arterial (AP) and venous phase (VP) slope of the spectral curve (λHU), iodine concentration (IC), normalized IC (NIC), effective atomic number (Zeff) and iodine-no-water concentration were retrospectively compared between patients with low and high Ki-67 expression levels and with different histological types in GC patients. The ROI was outlined independently by two senior physicians, and the average of three measurements at the largest level was taken. In addition, interobserver reproducibility was assessed by Bland-Altman analysis. Correlations between quantitative parameters and Ki-67 expression levels were assessed by Spearman\'s correlation coefficients.
RESULTS: The values between the mucinous group and nonmucinous carcinoma group were significantly different in both phases. The IC, NIC, and iodine-no-water concentration in the VP were significantly different among the Ki-67_L, Ki-67_M, and Ki-67_H groups. Spearman rank correlation analysis demonstrated a positive correlation between Ki-67 expression levels and IC, NIC, and iodine-no-water concentration in the VP, with correlation coefficients of 0.304, 0.424, and 0.322, respectively.
CONCLUSIONS: Quantitative spectral parameters can discriminate between low and high Ki-67 expression and different histological types in GC. The NIC, IC and iodine-no-water concentration can be useful parameters for evaluating of Ki-67 expression levels.
摘要：
目的：探讨新的能谱CT参数对胃癌组织学类型和Ki-67表达的诊断能力。
方法：回顾性研究了72例经组织学证实的胃癌（GC）患者。所有患者均行腹部能谱CT双期增强。频谱曲线的动脉（AP）和静脉相（VP）斜率（λHU），碘浓度（IC），归一化IC(NIC)，回顾性比较了GC患者中Ki-67低表达水平和高表达水平以及不同组织学类型的患者的有效原子序数（Zeff）和无水碘浓度。投资回报率由两名高级医生独立概述，并取三个最大水平测量值的平均值。此外,通过Bland-Altman分析评估观察者间的可重复性.通过Spearman相关系数评估定量参数与Ki-67表达水平之间的相关性。
结果：黏液性癌组和非黏液性癌组的值在两个阶段都有显著差异。IC,NIC,VP中的碘-无水浓度在Ki-67_L之间存在显着差异，Ki-67_M,和Ki-67_H组。Spearman秩相关分析显示Ki-67表达水平与IC呈正相关,NIC,和VP中的碘-无水浓度，相关系数分别为0.304、0.424和0.322。
结论：定量光谱参数可以区分GC中Ki-67的低表达和高表达以及不同的组织学类型。NIC,IC和无水碘浓度可作为评价Ki-67表达水平的有用参数。
方法：回顾性研究了72例经组织学证实的胃癌（GC）患者。所有患者均行腹部能谱CT双期增强。频谱曲线的动脉（AP）和静脉相（VP）斜率（λHU），碘浓度（IC），归一化IC(NIC)，回顾性比较了GC患者中Ki-67低表达水平和高表达水平以及不同组织学类型的患者的有效原子序数（Zeff）和无水碘浓度。投资回报率由两名高级医生独立概述，并取三个最大水平测量值的平均值。此外,通过Bland-Altman分析评估观察者间的可重复性.通过Spearman相关系数评估定量参数与Ki-67表达水平之间的相关性。
结果：黏液性癌组和非黏液性癌组的值在两个阶段都有显著差异。IC,NIC,VP中的碘-无水浓度在Ki-67_L之间存在显着差异，Ki-67_M,和Ki-67_H组。Spearman秩相关分析显示Ki-67表达水平与IC呈正相关,NIC,和VP中的碘-无水浓度，相关系数分别为0.304、0.424和0.322。
结论：定量光谱参数可以区分GC中Ki-67的低表达和高表达以及不同的组织学类型。NIC,IC和无水碘浓度可作为评价Ki-67表达水平的有用参数。
