Department of diagnostic and interventional Radiology, Technische Universität München, Munich, Germany.
Philips GmbH Innovative Technologies, Research Laboratories, Hamburg, Germany.
Sci Rep. 2018 Nov 26;8(1):17386. doi: 10.1038/s41598-018-35888-1.
The purpose of this study was to investigate a preclinical spectral photon-counting CT (SPCCT) prototype compared to conventional CT for pulmonary imaging. A custom-made lung phantom, including nodules of different sizes and shapes, was scanned with a preclinical SPCCT and a conventional CT in standard and high-resolution (HR-CT) mode. Volume estimation was evaluated by linear regression. Shape similarity was evaluated with the Dice similarity coefficient. Spatial resolution was investigated via MTF for each imaging system. In-vivo rabbit lung images from the SPCCT system were subjectively reviewed. Evaluating the volume estimation, linear regression showed best results for the SPCCT compared to CT and HR-CT with a root mean squared error of 21.3 mm, 28.5 mm and 26.4 mm for SPCCT, CT and HR-CT, respectively. The Dice similarity coefficient was superior for SPCCT throughout nodule shapes and all nodule sizes (mean, SPCCT: 0.90; CT: 0.85; HR-CT: 0.85). 10% MTF improved from 10.1 LP/cm for HR-CT to 21.7 LP/cm for SPCCT. Visual investigation of small pulmonary structures was superior for SPCCT in the animal study. In conclusion, the SPCCT prototype has the potential to improve the assessment of lung structures due to higher resolution compared to conventional CT.
本研究旨在比较一种临床前能谱光子计数 CT（SPCCT）原型与常规 CT 对肺部成像的性能。使用定制的肺部体模，包括不同大小和形状的结节，对临床前 SPCCT 和常规 CT 进行标准和高分辨率（HR-CT）模式的扫描。通过线性回归评估体积估计，用 Dice 相似系数评估形状相似性。用每个成像系统的调制传递函数（MTF）研究空间分辨率。对 SPCCT 系统的活体兔肺图像进行主观评估。评估体积估计时，线性回归显示 SPCCT 与 CT 和 HR-CT 相比结果最佳，SPCCT、CT 和 HR-CT 的均方根误差分别为 21.3mm、28.5mm 和 26.4mm。Dice 相似系数在所有结节形状和大小上，SPCCT 均优于 CT 和 HR-CT（平均值，SPCCT：0.90；CT：0.85；HR-CT：0.85）。10% MTF 从 HR-CT 的 10.1 LP/cm 提高到 SPCCT 的 21.7 LP/cm。动物研究中，SPCCT 对较小的肺部结构的观察明显优于 CT。总之，与常规 CT 相比，SPCCT 原型具有更高的分辨率，有望改善对肺部结构的评估。
