Correlation between Dual-Phase Quantitative Parameters from Dual-Layer Spectral Detector Computed Tomography and Ki-67 Expression in Non-Small Cell Lung Cancer
-
摘要:
目的:研究双层探测器光谱CT(DLSCT)双期定量参数对非小细胞肺癌Ki-67表达的预测价值。方法:回顾性分析我院自2022年8月至2024年12月进行DLSCT双期增强扫描且经病理证实的非小细胞肺癌患者77例,按免疫组化结果分为低表达组(Ki-67≤30%)、高表达组(Ki-67>30%)。使用Spectral CT viewer软件测量、计算、分析两组病例动脉期和静脉期的双层光谱CT定量参数,包括碘密度(IC)、标准化碘密度(NIC)、有效原子序数(Zeff)、能谱曲线斜率(K40-100 keV,简称K)、MonoE(单能量光谱结果)间隔10 keV的CT40 keV-CT100 keV。统计学方法:采用独立样本t检验方法比较组间差异;用Spearman相关分析评价DLSCT双期定量参数和Ki-67表达水平间的相关性;绘制受试者工作曲线(ROC),获得曲线下面积(AUC),约登指数、敏感度、特异度衡量DLSCT各定量参数评估Ki-67表达水平的效能。结果:静脉期低表达组IC、NIC、Zeff、K40-100 keV、CT40 keV-CT70 keV(间隔10 keV)均高于高表达组,动脉期低表达组K40-100 keV、CT40 keV高于高表达组,差异均具有统计学意义。静脉期IC、NIC、Zeff、K40-100 keV、CT40 keV-CT60 keV(间隔10 keV)、动脉期K40-100 keV、CT40 keV与Ki-67表达水平呈负相关。绘制ROC,静脉期K40-100 keV评估非小细胞肺癌Ki-67表达水平最佳。结论:DLSCT双期定量参数是预测非小细胞肺癌 Ki-67 表达水平的有效工具,研究证据表明静脉期能谱曲线斜率 (K) 是其中最具预测价值的指标。
Abstract:Objective: We investigated the predictive value of dual-phase quantitative parameters of dual-layer spectral detector computed tomography (DLSCT) combined with Ki-67 expression in non-small-cell lung cancer (NSCLC). Methods: Seventy-seven patients with pathologically confirmed non-small cell lung cancer who underwent dual-phase enhanced scanning at our hospital between August 2022 and December 2024 were retrospectively analyzed. According to immunohistochemical results, they were divided into low (Ki-67≤30%) and high (Ki-67>30%) Ki-67 expression groups. Spectral CT viewer software was used to measure, calculate, and analyze the quantitative parameters obtained with dual-layer spectral CT in the arterial and venous phases in both groups, including iodine density (IC), standardized iodine density (NIC), effective atomic number (Zeff), and energy spectrum curve slope (K, P < 0.05) (referred to as K and MonoE [monochromatic energy spectroscopy]) results, and CT40 keV-CT100 keV at 10 keV intervals. An independent samples t-test was used to compare differences between groups. Spearman’s correlation analysis was used to evaluate the correlation between the quantitative parameters of DLSCT and Ki-67 expression. A receiver-operating characteristic (ROC) curve was constructed to obtain the area under the curve (AUC). Youden index, sensitivity, and specificity were used to measure the efficacy of each quantitative parameter of DLSCT in predicting Ki-67 expression. Results: IC, NIC, Zeff, K40-100 keV, CT40 keV-CT70 keV (interval 10 keV) were higher in the low expression group than in the high expression group in venous phase, and K40-100 keV and CT40 keV were higher in the low expression group than in the high expression group in arterial phase. The differences were statistically significant (P<0.05). IC, NIC, Zeff, K40-100 keV, CT40 keV-CT60 keV (interval 10 keV) in venous phase, and K40-100 keV, CT40 keV in arterial phase correlated negatively with Ki-67 expression level (|r| < 0.40,P < 0.05). The ROC curve showed that K40-100 keV in venous phase was the best parameter for predicting Ki-67 expression in NSCLC (AUC=0.750). Conclusion: Dual-phase quantitative parameters of DLSCT are effective tools for predicting Ki-67 expression in non-small cell lung cancer, and research evidence shows that the slope (K) of the spectral curve in the venous phase is the most valuable index.
-
Keywords:
- spectral CT /
- carcinoma non-small-celllung /
- Ki-67 proliferation.
-
冠状动脉CT血管成像(coronary CT angiography,CCTA)作为临床诊断、筛查冠状动脉疾病[1-2]及预测心血管事件[3]的无创影像学检查手段,并在临床中广泛应用。CCTA图像质量影响冠状动脉狭窄程度评估,CCTA检查的辐射剂量及碘对比剂不良反应亦倍受关注[4-5]。本研究回顾性分析影响第三代双源CT检查的冠状动脉血管成像客观图像质量因素,协助技师更加准确、合理的选择扫描参数及注射方案,旨在提高患者检查成功率及降低辐射剂量及碘摄入量。
1. 资料与方法
1.1 一般资料
回顾性连续收集自2020年1月至2021年6月在本院行第三代双源CT冠状动脉CT血管成像患者
1035 例。纳入标准:①患者具有完整基本临床信息、扫描参数;②钙化积分≤1000 患者。排除标准:①肾功能(肌酐 > 1.7 mg/dL)不全患者;②碘对比剂过敏的患者;③图像质量主观评价标准差[1]的患者,如冠状动脉节段中的40%(15个节段中的6个节段)有伪影;④既往有冠状动脉腔内成形术、冠状动脉支架植入术、冠状动脉搭桥术、心脏瓣膜置换术及起搏器、除颤器植入等手术史。符合标准纳入研究对象共684例患者。本研究通过本院医学伦理委员会审查批准。1.2 冠状动脉CT血管成像方法
1.2.1 患者准备:
患者进行严格的呼吸训练;检查前均不使用控制心率药物;测量患者身高与体重;于受检者左手肘正中静脉预埋留置针。
1.2.2 检查方法:所有患者均行第三代双源CT(SIEMENS Force
双源CT)进行冠状动脉CTA成像,扫描范围自气管隆突下方1 cm至心脏膈面。监测层面为升主动脉起始部,阈值100 HU,达阈值后自动触发扫描。对比剂和生理盐水均用双筒高压注射器注入。扫描参数:回顾性或前瞻性心电门控,管电压70-120 KV,管电流参考值为280 mAs/rot,准值器192 mm×0.6 mm,层厚0.75 mm,旋转时间0.25 s;重建算法采用高级建模迭代重建(advanced modeled iterative reconstruction,ADMIRE),迭代强度3。
1.2.3 图像分析:
由两名具有3年以上从事心血管放射诊断医师测量左主干、左前降支近段、左回旋支近段及右冠状动脉近段CT值并取均匀值。感兴趣区(region of interest,ROI)面积大约所测血管管腔面积80%且避开血管壁边缘及钙化、非钙化斑块,每支血管测量三次取平均数。
1.2.4 观察分析因素:
根据血管强化程度,若四支血管的CT值均为400 HU~900 HU,将评价为客观图像质量好,若其中一支血管的CT值 < 400 HU或CT值 > 900 HU,则为客观图像质量差,CT值 < 400 HU作为客观图像质量差的依据来源Xu等[6]人研究结果,而冠状动脉CT值过高影响非钙化斑块的显示[7],因此本研究尝试将CT值 > 900 HU作为客观图像质量差。记录患者基本临床信息(包括年龄、性别、身高、体重、体重指数(body mass index,BMI)、心率、心律是否齐)、扫描方案(包括对比剂剂量、对比剂注射率、碘浓度、管电压、是否大螺距Flash扫描)和钙化积分;根据2016年中国超重/肥胖问题医学营养治疗专家共识按照BMI值(体重kg/身高的平方m2)将患者分为四组:偏瘦组(BMI < 18.5)、正常组(18.5≤BMI<24)、超重组 (24≤BMI<28)、肥胖组(BMI≥28)。将心率分为低心率组(低于60)、正常心率组(60~100)、高心率组(高于100)。将钙化积分分为四组(0、1~99、100~399、400~
1000 )。1.3 统计学方法
采用SPSS 20.0、MedCalc、GraphPad Prism 5及R语(3.5.2版)统计软件,P<0.05作为有统计学差异,符合正态分布采用t检验,不符合正态分布采用秩和检验、卡方或Fisher确切检验方法;将单因素分析中P<0.05的变量作为二元Logistic回归输入变量,建立Logistic回归预测模型,用MedCalc绘制受试者操作特征曲线(Receiver Operating Characteristic,ROC)曲线,并利用R语制作列线图模型。
2. 结果
2.1 影响客观图像质量的因素
在684例患者中,其中79例患者客观图像质量差,50例患者CT值<400 HU,29例患者CT值>900 HU;605例患客观图像质量好;患者的BMI(P<0.001)、碘浓度(P=0.001,P<0.05)、对比剂剂量(P=0.005,P<0.05)、对比剂注射速率(P=0.010,P<0.05)及管电压(P<0.001)在两组中差异具有统计学意义,患者的性别、年龄、心率、心律是否齐、身高、体重、钙化积分及是否为大螺距Flash扫描在两组间差异无统计学意义,具体结果见表1。
表 1 客观图像质量差与客观图像质量好两组在患者基本临床信息及扫描参数中比较Table 1. Comparison of poor objective image quality and good objective image quality in terms of the basic clinical information and scanning parameters.客观图像质量差
(N=79)客观图像质量好
(N=605)$t/T/\chi^2 $ P 性别 3.607 0.058 女 43.0(54.4%) 261.0(43.1%) 男 36.0(45.6%) 344.0(56.9%) 年龄(岁) 62.5 ±12.5 62.4 ±12.7 0.073 0.942 钙化积分 3.136 0.371 0 49.0(62.0%) 321.0(53.1%) 1~99 17.0(21.5%) 142.0(23.5%) 100~399 7.0(8.9%) 92.0(15.2%) 400~ 1000 6.0(7.6%) 50.0(8.3%) 身高(cm) 160.0(138.0,185.0) 160.0(137.0,180.0) −0.403 0.687 体重(Kg) 65.3(29.0,95.0) 61.9(36.0,91.0) −1.920 0.055 BMI(kg/m2) 18.344 < 0.001 偏瘦 5.0(6.3%) 21.0(3.5%) 正常 26.0(32.9%) 274.0(45.3%) 超重 25.0(31.6%) 242.0(40.0%) 肥胖 23.0(29.1%) 68.0(11.2%) 心率(次/分钟) 0.261 0.877 <60 8.0(10.1%) 51.0(8.4%) 60~100 64.0(81.0%) 501.0(82.8%) >100 7.0(8.9%) 53.0(8.8%) 心律 0.707 0.401 窦性律齐 71.0(89.9%) 560(92.6%) 心律不齐 8.0(10.1%) 45.0(7.4%) 碘浓度(mgI/ml) 370.0(300.0, 400.0) 370.0(300.0, 400.0) −3.180 0.001 对比剂剂量(ml) 45.0 (21.0, 65.0) 40.0 (4.0, 65.0) −2.801 0.005 注射速率(ml/s) 4.0 (3.0, 5.0) 4.00 (3.0, 5.0) −2.568 0.010 管电压(Kv) 80.0 (70.0, 120.0) 70.0 (70.0, 120.0) −5.981 < 0.001 扫描方式 1.141 0.707 非Flash 66.0(83.5%) 495.0(81.8%) Flash 13.0(16.5%) 110.0(18.2%) 2.2 建立预测客观图像质量好的模型
将单因素分析中患者的BMI、碘浓度、对比剂剂量、对比剂注射速率及管电压作为二元Logistic输入变量,其中BMI、碘浓度及管电压是预测客观图像质量好的独立危险因素,结果详见表2。建立二元Logistic回归模型如下:
表 2 影响客观图像质量的独立危险因素Table 2. Independent risk factors affecting the objective image qualityβ S.E, Wals P OR 95%CI BMI 参考 8.066 0.045 BMI(1) −1.500 0.656 5.235 0.022 0.223 0.062-0.806 BMI(2) −0.506 0.454 1.243 0.265 0.603 0.248-1.467 BMI(3) 0.046 0.4 0.013 0.909 1.047 0.477-2.295 碘浓度 −0.009 0.005 3.969 0.046 0.991 0.982-1.000 对比剂剂量 −0.019 0.025 0.544 0.461 0.982 0.934-1.031 对比剂注射速率 −0.210 0.365 0.332 0.565 0.810 0.396-1.658 管电压 −0.096 0.016 35.002 0 0.908 0.88-0.938 常量 14.743 2.601 32.128 0 2527098.094 $$ \begin{split} &{\mathrm{P}}=1/1+{\mathrm{exp}}(-(14.743-1.5\times {\mathrm{BMI}}(1)-0.506\times\\ &{\mathrm{BMI}}(2)+0.046\times {\mathrm{BMI}}(3)+0\times {\mathrm{BMI}}(4)-0.009\times\\ &碘浓度-0.019\times 对比剂计量-0.210\times \\ &对比剂注射速率-0.096\times 管电压))。 \end{split} $$ (1) ROC曲线下面积(AUC)为0.757(95%CI:0.723-0.789),最佳临界值为
0.9168 ,敏感性61.32%,特异性83.54%,结果见图1。并利用R语绘制列线图模型见图2,图3是利用预测模型来预测一例患者冠状动脉CTA图像的客观质量。图3(a)~(d)患者男,身高1.7 m,体重75 Kg,BMI=33.33,肥胖型(BMI4)患者,行第三代双源CT冠状动脉血管成像,客观图像质量好(冠状动脉CT值约500 HU~600 HU),注射碘浓度400 Img/dL,注射速率4 mL/s,对比剂总量40 mL,管电压70 KV,经过二元Logistc回归预测模型P=1/1+exp(−(14.743−1.5×BMI(1)−0.506×BMI(2)+0.046×BMI(3)+0×BMI(4)−0.009×碘浓度−0.019×对比剂计量−0.210×对比剂注射速率−0.096×管电压)),P=
0.9439 >0.9168 ,客观图像质量好,经过列线图模型,总分约142分,对应的预测风险值高于95%,说明成为客观图像质量好的可能性大。2.3 管电压、碘浓度在不同BMI患者中冠状动脉血管CT值之间关系
本研究中患者采用70 kV~120 kV,随着管电压越高,冠状动脉血管CT值越低,若冠状动脉CT值相同,BMI指数越高所需管电压越高,见图4(a);本研究中患者采用300 mgI/ml~400 mgI/ml,碘浓度越高,冠状动脉血管CT值越高,若冠状动脉CT值相同,BMI指数越高所需的碘浓度越大,见图4(b)。
图4中(a)示不同BMI患者中管电压越高,CT值越低;在相同的冠状动脉CT值中,偏瘦患者需要的管电压低于正常患者低于超重患者低于肥胖患者,本研究中最低管电压为70 KV。(b)示不同BMI患者中碘浓度越高,冠状动脉CT值越高,在相同的冠状动脉CT值(小于700-799 HU)中,偏瘦患者需要的碘浓度低于正常患者低于超重患者低于肥胖患者。
3. 讨论
本研究根据Xu等[6]研究报道及CT值过高会影响非钙化斑块显示[7],将左冠状动脉主干及其三大分支近段的CT值400 HU~900 HU为客观图像质量好,其中任何一支血管CT值低于400 HU或高于900 HU为客观图像质量差, 而客观图像质量差的上限CT值目前鲜有相关文献报道,本研究结果显示CT值高于900 HU患者占总纳入对象约4.25%,占小概率事件,因此尝试将CT值高于900 HU作为客观图像质量差。
本研究结果显示BMI、碘浓度、管电压是影响客观图像质量的独立危险因素。随着BMI指数增加,X线穿透作用降低,冠状动脉血管CT值降低,如果按照统一剂量注射方式可能影响高BMI患者客观图像质量,而对低BMI患者而言对比剂剂量可能偏高[8];同时需要更高的管电压降低图像噪声,有研究采用深度学习图像重建可以提高图像质量[9]。在相同的对比剂剂量用量及注射速率,碘浓度越高,体内血管含碘量越高,CT值越高;高对比剂剂量可对肾脏造成不可逆性损伤及提高碘对比剂不良反应的发生,注射速率越快将会增加对比剂外渗的风险[10];因此在保障血管内单位体积内碘含量一定的情况下,针对不同患者,需要平衡对比剂剂量、对比剂速率及碘浓度之间的关系。既往大量文献[11-14]研究报道,利用低管电压、低对比剂总量扫描方案降低CT冠状动脉血管成像辐射剂量及碘摄入量。
随着CCTA临床广泛应用及计算机辅助诊断评估冠状动脉狭窄程度软件的应用增加[15],需要个体化扫描方案来保障图像质量及扫描成功率。本研究建立二元Logistic回归预测模型,将复杂的数学公式转化为列线图模型,列线图模型可以协助影像技师针对不同的患者设计更合理的扫描方案,提高扫描成功率及实现低辐射剂量及低碘的摄入量。
本研究局限性及不足:本研究非多中心研究、仅用第三代SIEMENS ForceCT设备,缺乏广泛的推广性;且未考虑患者心脏体积、心功等因素对于CCTA图像质量的影响;因此未来工作中仍需要进一步补充临床数据来完善标准化、个体化、精准化的扫描方案及更多中心样本来验证研究结果。
综上所述,计算机预测模型能够方便、简洁地制定个体化扫描方案,保障第三代双源CT冠状动脉血管成像图像质量前提下,降低患者辐射剂量及碘摄入量。
-
表 1 Ki-67高、低表达组静脉期光谱CT各参数比较
Table 1 Comparison of spectral CT parameters in venous phase from high and low Ki-67 expression groups
参数 组别 统计检验 低表达组 高表达组 t值 P值 n 27 50 IC/(mg/mL) 1.37±0.39 1.12±0.36 2.9 0.01 NIC 0.31±0.08 0.25±0.08 3.27 <0.01 Zeff 8.08±0.18 7.95±0.26 2.3 0.02 K40-100 keV 1.87±0.44 1.43±0.48 3.93 <0.01 CT40 keV/HU 164.68±32.27 137.72±34.98 3.31 <0.01 CT50keV/HU 121.38±26.42 103.3±25.39 2.94 <0.01 CT60 keV/HU 93.03±17.37 81.84±17.87 2.65 0.01 CT70 keV/HU 75.8±13.62 68.37±13.14 2.34 0.02 CT80 keV/HU 63.86±12.76 60.71±11.53 1.1 0.28 CT90 keV/HU 56.6±12.92 55.38±9.96 0.46 0.65 CT100 keV/HU 52.68±11.97 51.78±9.02 0.37 0.71 表 2 Ki-67高、低表达组动脉期光谱CT各参数比较
Table 2 Comparison of arterial phase spectral CT parameters from high and low Ki-67 expression groups
参数 组别 统计检验 低表达组 高表达组 t值 P值 n 27 50 IC/(mg/mL) 1.31±0.39 1.15±0.36 1.5 0.14 NIC 0.11±0.03 0.09±0.04 1.75 0.08 Zeff 7.99±0.24 7.95±0.26 0.66 0.51 K40-100 keV 1.61±0.45 1.33±0.50 2.42 0.02 CT40 keV/HU 150.30±31.75 132.03±35.03 2.26 0.03 CT50keV/HU 109.08±21.23 100.58±24.32 1.53 0.13 CT60 keV/HU 86.11±15.43 80.42±16.98 1.45 0.15 CT70 keV/HU 72.69±12.37 68.32±12.50 1.47 0.15 CT80 keV/HU 63.54±10.60 60.60±9.96 1.21 0.23 CT90 keV/HU 57.66±9.72 55.51±8.26 1.03 0.31 CT100 keV/HU 53.54±9.23 52.01±7.19 0.81 0.42 表 3 静脉期光谱CT各参数与Ki-67表达水平的相关性分析
Table 3 Correlation analysis between Ki-67 expression and parameters from venous phase spectral CT
r值 P值 分组 1 IC(mg/ml) −0.267 0.02 NIC −0.297 0.01 Zeff −0.251 0.03 K40-100 keV −0.398 <0.01 CT40 keV(HU) −0.315 0.01 CT50keV(HU) −0.278 0.01 CT60 keV(HU) −0.243 0.03 CT70 keV(HU) −0.194 0.10 CT80 keV(HU) −0.062 0.60 CT90 keV(HU) −0.007 −0.95 CT100 keV(HU) −0.007 0.95 表 4 动脉期光谱CT各参数与Ki-67表达水平的相关性分析
Table 4 Correlation analysis between Ki-67 expression and parameters from arterial phase spectral CT
分组 K40-100 keV CT40 keV(HU) r值 1 −0.225 −0.225 P值 0.05 <0.05 表 5 光谱CT各参数诊断Ki-67高表达组与非高表达组肺癌病灶的效能
Table 5 Efficacy of spectral CT parameters in diagnosis of lung cancer lesions in the high Ki-67 group and the low Ki-67 group
指标 约登指数 临界值 敏感度(%) 特异度(%) AUC 95%CI IC (V) 0.284 1.145 70.4 58.0 0.674 0.549-0.799 NIC(V) 0.275 0.245 81.5 46.0 0.683 0.561-0.804 Zeff(V) 0.292 7.925 85.2 44.0 0.660 0.538-0.782 K40-100 keV(V) 0.409 1.366 88.9 52.0 0.750 0.641-0.859 CT40 keV(V) 0.347 150.772 66.7 68.0 0.698 0.575-0.820 CT50 keV(V) 0.356 116.921 55.6 80.0 0.679 0.549-0.809 CT60 keV(V) 0.353 89.047 59.3 76.0 0.666 0.536-0.796 CT70 keV(V) 0.316 74.610 55.6 76.0 0.644 0.513-0.776 K40-100 keV(A) 0.321 1.407 74.1 58.0 0.662 0.537-0.788 CT40 keV(A) 0.295 130.264 81.5 48.0 0.657 0.531-0.783 注:AUC:曲线下面积;CT40 keV(V)、CT40 keV(A):分别代表静脉期CT40 keV、动脉期CT40 keV,余数据以此类推。 -
[1] KIRI S, RYBA T. Cancer, metastasis, and the epigenome[J]. Molecular Cancer, 2024, 23(1): 154. DOI: 10.1186/s12943-024-02069-w.
[2] SIEGEL R L, GIAQUINTO A N, JEMAL A. Cancer statistics, 2024[J]. CA: a cancer journal for clinicians, 2024, 74(1). DOI: 10.3322/caac.21820
[3] LEITER A, VELUSWAMY R R, WISNIVESKY J P. The global burden of lung cancer: current status and future trends[J]. Nature reviews Clinical oncology, 2023, 20(9): 624-639. DOI: 10.1038/s41571-023-00798-3.
[4] MROUJ K, ANDRéS-SáNCHEZ N, DUBRA G, et al. Ki-67 regulates global gene expression and promotes sequential stages of carcinogenesis[J]. Proceedings of the National Academy of Sciences, 2021, 118(10): e2026507118. DOI: 10.1073/pnas.2026507118.
[5] LUO X, ZHENG R, ZHANG J, et al. CT-based radiomics for predicting Ki-67 expression in lung cancer: a systematic review and meta-analysis[J]. Frontiers in Oncology, 2024, 14: 1329801. DOI: 10.3389/fonc.2024.1329801.
[6] DENG L, YANG J, ZHANG M, et al. Whole-lesion iodine map histogram analysis versus single-slice spectral CT parameters for determining novel International Association for the Study of Lung Cancer grade of invasive non-mucinous pulmonary adenocarcinomas[J]. Diagnostic and Interventional Imaging, 2024, 105(5): 165-173. DOI: 10.1016/j.diii.2023.12.001.
[7] MA Y, LI S, HUANG G, et al. Role of iodine density value on dual-energy CT for detection of high tumor cell proportion region in lung cancer during CT-guided transthoracic biopsy[J]. European Journal of Radiology, 2023, 160: 110689. DOI: 10.1016/j.ejrad.2023.110689.
[8] LIN L, CHENG J, TANG D, et al. The associations among quantitative spectral CT parameters, Ki-67 expression levels and EGFR mutation status in NSCLC.[J]. Sci Rep, 2020, 1: 3436. DOI: 10.1038/s41598-020-60445-0.
[9] ZHU T, XIE K, WANG C, et al. Diagnostic Effectiveness of Dual Source Dual Energy Computed Tomography for Benign and Malignant Thyroid Nodules[J]. Evidence‐Based Complementary and Alternative Medicine, 2022, 2022(1): 2257304. DOI: 10.1155/2022/2257304.
[10] 中华放射学杂志双层探测器光谱CT临床应用协作组. 双层探测器光谱CT临床应用中国专家共识(第一版)[J]. 中华放射学杂志, 2020, 54(7): 635-643. DOI: 10.3760/cma.j.cn112149-20200513-00679. CHINESE JOURNAL OF RADIOLOGY DUAL-LAYER SPECTRAL DETECTOR CT CLINICAL APPLICATION COLLABORATIVE GROUP. Chinese expert consensus on clinical application of dual-layer spectral detector CT (first edition)[J]. Chinese Journal of Radiology, 2020, 54(7): 635-643. DOI: 10.3760/cma.j.cn112149-20200513-00679.
[11] FULTON N, RAJIAH P. Abdominal applications of a novel detector-based spectral CT[J]. Current Problems in Diagnostic Radiology, 2018, 47(2): 110-118. DOI: 10.1067/j.cpradiol.2017.05.001.
[12] ZHANG Z, ZOU H, YUAN A, et al. A Single Enhanced Dual-Energy CT Scan May Distinguish Lung Squamous Cell Carcinoma From Adenocarcinoma During the Venous phase.[J]. Acad Radiol, 2020, 5: 624-629. DOI: 10.1016/j.acra.2019.07.018.
[13] 薛莉雅, 赵卫东, 苏琳, 等. 双层探测器光谱CT多参数成像在不同病理类型肺癌中的应用[J]. 中国CT和MRI杂志, 2023, 21(12): 52-55. DOI: 10.3969/j.issn.1672-5131.2023.12.016. XUE L Y, ZHAO W D, SU L, et al. Application of multi-parameter imaging of dual-layer spectral detector CT in different pathological types of lung cancer[J]. Chinese journal of CT and MRI, 2023, 21(12): 52-55. DOI: 10.3969/j.issn.1672-5131.2023.12.016.
[14] 刘秀丽, 张戟风, 刘景旺, 等. 能谱CT在中央型肺癌伴阻塞性肺不张诊断及放疗定位中应用价值[J]. CT理论与应用研究, 2023, 32(4): 509-514. DOI: 10.15953/j.ctta.2022.164. LIU X L, ZHANG J F, LIU J W, et al. The value of Spectral CT in differential diagnosis and ra-diotherapy localiation of central lung cancer with obstructive atelectasis[J]. CT Theory and App-lications, 2023, 32(4): 509-514. DOI: 10.15953/j.ctta.2022.164.
[15] WU J, LV Y, WANG N, et al. The value of single-source dual-energy CT imaging for discriminating microsatellite instability from microsatellite stability human colorectal cancer.[J]. Eur Radiol, 2019, 7: 3782-3790. DOI: 10.1007/s00330-019-06144-5.
[16] 田双凤, 杨萌, 夏建国, 等. 实性肺癌能谱CT参数与Ki-67表达水平的相关性研究[J]. 影像诊断与介入放射学, 2021, 30(1): 20-24. DOI: 10.3969/j.issn.1005-8001.2021.01.004. TIAN S F, YANG M, XIA J G, et al. Correlation between spectral CT parameters and Ki-67 expression in solid lung cancer [J]. The imaging diagnosis and interventional radiology, 2021, 30 (1) : 20 to 24. DOI: 10.3969 / j.i SSN. 1005-8001.2021.01.004.
[17] 周潋滟, 张浩荡, 殷世武. 双层光谱CT评估非小细胞肺癌Ki-67表达水平的可行性[J]. 中国介入影像与治疗学, 2023, 20(2): 107-111. DOI: 10.13929/j.issn.1672-8475.2023.02.011. ZHOU L Y, ZHANG H D, YIN S W. Feasibility of assessing Ki-67 expression level in non-small cell lung cancer using dual-layer spectral CT[J]. Chinese interventional imaging and therapy, 2023, 20(2): 107-111. DOI: 10.13929/j.issn.1672-8475.2023.02.011.
[18] MAO L T, CHEN W C, LU J Y, et al. Quantitative parameters in novel spectral computed tomography: Assessment of Ki-67 expression in patients with gastric adenocarcinoma[J]. World Journal of Gastroenterology, 2023, 29(10): 1602. DOI: 10.3748/wjg.v29.i10.1602.
[19] ZEGADŁO A, ŻABICKA M, RóŻYK A, et al. A new outlook on the ability to accumulate an iodine contrast agent in solid lung tumors based on virtual monochromatic images in dual energy computed tomography (DECT): Analysis in two phases of contrast enhancement[J]. Journal of Clinical Medicine, 2021, 10(9): 1870. DOI: 10.3390/jcm10091870.
[20] WU Y, LI J, DING L, et al. Differentiation of pathological subtypes and Ki-67 and TTF-1 expression by dual-energy CT (DECT) volumetric quantitative analysis in non-small cell lung cancer[J]. Cancer Imaging, 2024, 24(1): 146. DOI: 10.1186/s40644-024-00793-6.
[21] DOU P, LIU Z, XIE L, et al. The predictive value of energy spectral CT parameters for assessing Ki-67 expression of lung cancer[J]. Translational Cancer Research, 2020, 9(7): 4267. DOI: 10.21037/tcr-19-2769a.
[22] 窦沛沛, 赵恒亮, 曹爱红. 能谱CT联合肿瘤标志物预测肺腺癌Ki-67表达[J]. CT理论与应用研究, 2023, 32(6): 753-760. DOI: 10.15953/j.ctta.2022.172. DOU P P, ZHAO H L, CAO A H. Spectral CT combined with tumor markers to predict Ki-67 expression in lung adenocarcinoma[J]. CT Theory and Applications, 2023, 32(6): 753-760. DOI: 10.15953 / j.carol carroll tta. 2022.172. DOI: 10.15953/j.ctta.2022.172.
[23] YU J, LIN S, LU H, et al. Optimize scan timing in abdominal multiphase CT: Bolus tracking with an individualized post-trigger delay. [J]. Eur J Radiol, 2022: 110139. DOI: 10.1016/j.ejrad.2021.110139
[24] QI K, LI L, YUAN D, et al. Optimized contrast enhancement and homogeneity in aortic CT angiography: bolus tracking with personalized post-trigger delay[J]. Quantitative Imaging in Medicine and Surgery, 2024, 15(1): 709. DOI: 10.21037/qims-24-624.
[25] YUAN D, LI L, ZHANG Y, et al. Image quality improvement in head and neck CT angiography: Individualized post-trigger delay versus fixed delay. [J]. Eur J Radiol, 2023, 111142. DOI: 10.1016/j.ejrad.2023.111142