胰腺导管腺癌CT能谱成像参数的定量分析及潜在应用价值

The Characteristics and Its Potential Application Value of Pancreatic Ductal Adenocarcinoma with Single-source Dual Energy Spectral CT Imaging

目的:本研究应用能谱CT扫描成像,研究胰腺导管腺癌的能谱定量多参数,探讨胰腺导管腺癌CT能谱成像的参数特点及潜在应用价值。方法:回顾性分析经病理证实为胰腺导管腺癌,并均行胰腺能谱CT动脉晚期、门静脉期增强扫描的61例患者。记录胰腺癌病灶和胰腺实质的单能量CT值、有效原子序数(Effective-Z)、碘(水)基值、水(碘)基值。采用Wilcoxon符号秩和检验(非正态分布)或配对t检验(正态分布)比较胰腺癌和胰腺实质分别在动脉晚期和门静脉期间相应上述CT能谱成像参数的差异,并绘制相应能谱曲线。结果:动脉晚期胰腺导管腺癌单能量CT值明显低于周围正常胰腺,胰腺导管腺癌门静脉期单能量CT值高于动脉期,低于周围正常胰腺,差异在低能量段相当显著;胰腺导管腺癌与胰腺实质动静脉期能量段越低差异越明显,能量段越高,差异越小;胰腺导管腺癌与胰腺实质动静脉期的单能量CT值、配对基物质碘(水)基值、Effective-Z所对应均化浓度值有显著性差异,具有统计学意义,水(碘)值差异无统计学意义。结论:胰腺导管腺癌CT能谱成像的能谱参数具有一定特征。动静脉期胰腺癌单能量CT值、碘(水)基值、有效原子序数均低于相应胰腺实质,动脉晚期低于门静脉期,能量段越低差异越明显。综合应用多能量段和能谱多参数成像有助于提高能谱CT密度分辨力,具有为小胰腺癌早诊断提供影像信息的潜在价值。

Objective: To study the quantitative multi-parameters of CT energy spectrum imaging of pancreatic ductal adenocarcinoma by using enhanced CT energy spectrum imaging, and to explore the parameter characteristics and potential application value of CT energy spectrum imaging of pancreatic ductal adenocarcinoma. Methods: Retrospective analysis was performed on 61 patients with pancreatic ductal adenocarcinoma confirmed by pathology, all of whom underwent enhanced CT scan of advanced arterial and portal vein phase. Single energy CT value, Effective atomic number(Effective-Z), iodine(water) base value and water(iodine) base value of pancreatic cancer lesions and pancreatic parenchyma were recorded. Paired t test(normal distribution) or Wilcoxon signed-rank sum test(non-normal distribution) were used to compare the differences of the above CT energy spectrum imaging parameters between the late arterial period and portal vein period,pancreatic cancer and pancreatic parenchyma, and to plot the corresponding energy spectrum curves. Results: The single energy CT value of pancreatic ductal adenocarcinoma in advanced arterial stage was significantly lower than that in peripheral normal pancreas. The single energy CT value of pancreatic ductal adenocarcinoma in portal vein stage was higher than that in arterial stage and lower than that in peripheral normal pancreas. The lower the low energy segment is, the more significant the difference is. The higher the energy segment is, the smaller the difference is. There were significant differences in single energy CT value, paired base substance iodine(water)base value and Effective-Z corresponding homogenization concentration between pancreatic ductal adenocarcinoma and pancreatic parenchyma in arteriovenous phase, while there was no significant difference in water(iodine) value. Conclusion: The dual-phase enhanced energy spectrum parameters of CT imaging of pancreatic ductal adenocarcinoma have certain characteristics. The single energy CT value, iodine(water) base value and effective atomic number of pancreatic cancer in arteriovenous phase were lower than those in corresponding pancreatic parenchyma, and those in arterial late phase were lower than those in portal vein phase.The lower the energy segment, the more obvious the difference. The comprehensive application of multi-band and energy spectrum multi parameter imaging is helpful to improve the CT density resolution of pancreatic ductal adenocarcinoma, and has the potential value of providing image information for early diagnosis of small pancreatic cancer.