双层探测器光谱CT多参数成像鉴别局限性结直肠壁增厚良恶性的临床价值

Clinical Value of Dual-Layer Spectral Detector CT Multi-Parameter Imaging in Differentiating Benign and Malignant Localized Colorectal Wall Thickening

摘要: 目的：探讨双层探测器光谱CT动、静脉期定量参数对鉴别局限性结直肠壁增厚良恶性的临床价值。方法：回顾性分析2024年1月至2024年7月在扬州大学附属医院接受光谱CT腹部增强扫描的“局限性结直肠壁增厚(厚度 > 5 mm，长度 < 5 mm)”患者，并在1个月内接受了肠镜检查的65例患者。根据肠镜检查结果分为恶性组(n = 42)及良性组(n = 23)。纳入分析的临床特征包括年龄、性别和症状。常规CT特征包括病灶位置及肠壁厚度。测量并计算光谱CT动脉期(AP)和静脉期(VP)的碘浓度(IC)、标准化IC (NIC)、有效原子序数(Z_eff)、标准化Z_eff (NZ_eff)、动脉增强分数(AEF)和40~100 keV光谱曲线斜率(λ_HU)。采用SPSS 27.0软件进行统计学分析。符合正态分布的计量资料采用独立样本t检验比较组间差异，不符合正态分布的计量资料采用Mann-Whitney U检验比较组间差异。采用χ²检验比较组间各计数资料差异。采用受试者操作特征(ROC)曲线计算各参数评估局限性肠壁增厚良恶性的效能。选择曲线下面积(AUC) > 0.75的参数采用二元logistic回归建立联合参数，并评价其效能。结果：恶性组年龄、AP和VP的IC、NIC、Z_eff、NZ_eff及λ_vp均显著高于良性组，差异有统计学意义(p均 < 0.05)，良性组AEF高于恶性组，差异有统计学意义(p < 0.05)。其余参数差异无统计学意义(p均 > 0.05)。ROC曲线显示，VP中的IC、NIC、Z_eff、NZ_eff和λ_HU表现出较高的诊断性能，ROC曲线下面积(AUC)值分别为0.764、0.812、0.757、0.761和0.761。将AUC > 0.75的5个参数组成联合参数，其AUC值为0.867，灵敏度为88.10%，特异度为78.26%。结论：双层探测器光谱CT定量参数在区分良性和恶性局限性结直肠肠壁增厚方面有较好的应用价值，多参数联合可提高诊断效能。

Abstract: Objective: To investigate the clinical value of quantitative parameters of dual-layer spectral detector CT in differential diagnosis of benign and malignant localized colorectal wall thickening. Methods: A retrospective analysis of 65 patients with “localized colorectal wall thickening (thickness > 5 mm, length < 5 mm)” who received spectral CT enhanced abdominal scanning in the Affiliated Hospital of Yangzhou University from January 2024 to July 2024 and underwent colonoscopy within 1 month was performed. According to the results of colonoscopy, they were divided into malignant group (n = 42) and benign group (n = 23). Clinical characteristics included in the analysis included age, sex, and symptoms. Conventional CT features included lesion location and intestinal wall thickness. Iodine concentration (IC), standardized IC (NIC), effective atomic number (Z_eff), standardized Z_eff (NZ_eff), arterial enhancement fraction (AEF), and slope of 40 to 100 keV spectral curve (λ_HU) were measured and calculated for the arterial phase (AP) and venous phase (VP) of spectral CT. SPSS 27.0 software was used for statistical analysis. Independent sample t test was used to compare the differences between groups for measurement data conforming to normal distribution, and Mann-Whitney U test was used to compare the differences between groups for measurement data not conforming to normal distribution. χ² test was used to compare the difference of counting data between groups. The receiver operating characteristic (ROC) curve was used to calculate the parameters to evaluate the efficacy of local intestinal wall thickening. Parameters with area under the curve (AUC) > 0.75 were selected to establish joint parameters by binary logistic regression, and their efficiency was evaluated. Results: The IC, NIC, Z_eff, NZ_eff and λ_vp of AP and VP in malignant group were significantly higher than those in benign group (p < 0.05), and the AEF in benign group was higher than that in malignant group (p < 0.05). There was no significant difference in other parameters (all p > 0.05). ROC curve showed that IC, NIC, Z_eff, NZ_eff and λ_HU in VP showed high diagnostic performance, with area under ROC curve (AUC) values of 0.764, 0.812, 0.757, 0.761 and 0.761, respectively. The 5 parameters with AUC > 0.75 were combined with the AUC value of 0.867, the sensitivity of 88.10%, and the specificity of 78.26%. Conclusion: The quantitative parameters of dual-layer spectral detector CT have good application value in distinguishing benign and malignant localized colorectal wall thickening, and the combination of multiple parameters can improve the diagnostic efficiency.