胰腺导管腺癌患者虚拟单能量与多光谱图像的客观和主观比较。

Objective and subjective comparison of virtual monoenergetic vs. polychromatic images in patients with pancreatic ductal adenocarcinoma.

机构信息

Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.

Department of Surgery, Medical University of Vienna, Vienna, Austria.

出版信息

Eur Radiol. 2019 Jul;29(7):3617-3625. doi: 10.1007/s00330-019-06116-9. Epub 2019 Mar 19.

OBJECTIVES

The aim of this study was to assess the objective and subjective image characteristics of monoenergetic images (MEI[+]), using a noise-optimized algorithm at different kiloelectron volts (keV) compared to polyenergetic images (PEI), in patients with pancreatic ductal adenocarcinoma (PDAC).

METHODS

This retrospective, institutional review board-approved study included 45 patients (18 male, 27 female; mean age 66 years; range, 42-96 years) with PDAC who had undergone a dual-energy CT (DECT) of the abdomen for staging. One standard polyenergetic image (PEI) and five MEI(+) images in 10-keV intervals, ranging from 40 to 80 keV, were reconstructed. Line-density profile analysis, as well as the contrast-to-noise ratio (CNR) of the tumor, the signal-to-noise ratio (SNR) of the regular pancreas parenchyma and the tumor, and the CNR of the three main peripancreatic vessels, was calculated. For subjective quality assessment, two readers independently assessed the images using a 5-point Likert scale. Reader reliability was evaluated using an intraclass correlation coefficient.

RESULTS

Line-density profile analysis revealed the largest gradient in attenuation between PDAC and regular tissue in MEI(+) at 40 keV. Low-keV MEI(+)reconstructions at 40 and 50 keV increased CNR and SNR compared to PEI (40 keV: CNR 46.8 vs. 7.5; SNR 32.5 vs. 15.7; SNR 13.5 vs. 8.6; p < 0.001). MEI(+) at 40 keV and 50 keV were consistently preferred by the observers (p < 0.05), showing a high intra-observer 0.937 (0.92-0.95) and inter-observer 0.911 (0.89-0.93) agreement.

CONCLUSION

MEI(+) reconstructions at 40 keV and 50 keV provide better objective and subjective image quality compared to conventional PEI of DECT in patients with PDAC.

KEY POINTS

• Low-keV MEI(+) reconstructions at 40 and 50 keV increase tumor-to-pancreas contrast compared to PEI. • Low-keV MEI(+) reconstructions improve objective and subjective image quality parameters compared to PEI. • Dual-energy post-processing might be a valuable tool in the diagnostic workup of patients with PDAC.

目的

本研究旨在评估在不同千电子伏特（keV）下使用噪声优化算法的单能量图像（MEI[+]）与多能量图像（PEI）相比，在胰腺导管腺癌（PDAC）患者中的客观和主观图像特征。

方法

这是一项回顾性的机构审查委员会批准的研究，共纳入 45 名 PDAC 患者（18 名男性，27 名女性；平均年龄 66 岁；范围 42-96 岁），他们接受了腹部双能 CT（DECT）分期。重建了一个标准的多能量图像（PEI）和五个 10keV 间隔的 MEI[+]图像，keV 范围从 40 到 80keV。对线密度谱分析以及肿瘤的对比噪声比（CNR）、常规胰腺实质和肿瘤的信噪比（SNR）以及三个主要胰周血管的 CNR 进行了计算。对于主观质量评估，两位读者使用 5 分李克特量表独立评估图像。使用组内相关系数评估读者的可靠性。

结果

线密度谱分析显示，在 40keV 时，MEI[+]在 PDAC 和常规组织之间的衰减梯度最大。与 PEI 相比，低 keV 的 MEI[+]重建在 40keV 和 50keV 时增加了 CNR 和 SNR（40keV：CNR 46.8 对 7.5；SNR 32.5 对 15.7；SNR 13.5 对 8.6；p<0.001）。观察者一致更喜欢 MEI[+]在 40keV 和 50keV 时的表现（p<0.05），观察者之间的内一致性为 0.937（0.92-0.95），观察者之间的内一致性为 0.911（0.89-0.93）。