Johnsson A A, Svalkvist A, Vikgren J, Boijsen M, Flinck A, Kheddache S, Båth M
Department of Radiology, The Sahlgrenska Academy at University of Gothenburg, SE-413 45 Gothenburg, Sweden.
Radiat Prot Dosimetry. 2010 Apr-May;139(1-3):140-3. doi: 10.1093/rpd/ncq003. Epub 2010 Feb 4.
The aim of the present study was to investigate nodule size measurements with chest tomosynthesis (TS) and computed tomography (CT). A 26-mm thick phantom, composed of a Polylite block with embedded spheres of different materials and sizes (4-20 mm), was scanned by both CT and TS. Six observers without prior knowledge of the true diameters of the spheres independently measured the diameter of the spheres on the CT and TS images. Four observers were allowed to change the window settings and two of the observers used predetermined fixed viewing conditions. The mean relative errors for all observers and all measured spheres compared with the known diameter of the spheres were 1.4 % (standard deviation, SD: 5.4 %) on CT images and -1.1 % (SD: 5.0 %) on TS images. With regard to the four observers where the window settings were at the discretion of the observer, the mean relative errors were 1.4 % (SD: 6.4 %) on CT images and -1.7 % (SD: 5.7 %) on TS images. Regarding the two observers using identical viewing conditions the mean relative error was 1.5 % (SD: 2.8 %) on CT images and 0.2 % (SD: 2.6 %) on TS images. In conclusion, the study suggests that nodule size measurements on chest TS might be an alternative to measurements on CT.
本研究的目的是调查胸部断层合成摄影（TS）和计算机断层扫描（CT）对结节大小的测量情况。一个26毫米厚的体模，由一个嵌入了不同材料和尺寸（4 - 20毫米）球体的聚酯块组成，用CT和TS进行扫描。六名事先不知道球体真实直径的观察者分别在CT和TS图像上测量球体的直径。四名观察者可以改变窗口设置，两名观察者使用预先确定的固定观察条件。与球体已知直径相比，所有观察者和所有测量球体的平均相对误差在CT图像上为1.4%（标准差，SD：5.4%），在TS图像上为 - 1.1%（SD：5.0%）。对于四名可自行决定窗口设置的观察者，平均相对误差在CT图像上为1.4%（SD：6.4%），在TS图像上为 - 1.7%（SD：5.7%）。对于两名使用相同观察条件的观察者，平均相对误差在CT图像上为1.5%（SD：2.8%），在TS图像上为0.2%（SD：2.6%）。总之，该研究表明胸部TS上的结节大小测量可能是CT测量的一种替代方法。
