From the *Department of Radiology, University Hospital Freiburg, Freiburg; †Department of Medical Physics and Radiation Protection, University of Applied Sciences Gießen, Gießen; ‡Department of Radiology, Darmstadt Clinic, Darmstadt; and §Department of Plastic and Hand Surgery, University Hospital Freiburg, Freiburg, Germany.
Invest Radiol. 2014 Jul;49(7):491-7. doi: 10.1097/RLI.0000000000000042.
The aim of this study was to compare the image quality of a compact mobile flat-panel computed tomography (FPCT) capable of extremity imaging and a multidetector computed tomography (MDCT) in examinations with the same radiation dose.
Imaging with the FPCT was performed with default settings. Monte Carlo simulations were used to calculate equivalent dose settings for the 320-row MDCT. Simulations were based on and validated by dose measurements. Homogeneity, geometric distortion, artifacts, accuracy of Hounsfield values, contrast, and spatial resolution were evaluated in different imaging phantoms. Whitney-Mann U Test and Spearman ρ were used for statistical analysis.
Homogeneity reached 2.5% for the FPCT and 0.5% for the MDCT. Hounsfield values were more accurate and contrast to noise ratios were higher for the MDCT than the FPCT (P ≤ 0.001). The MDCT depicted more rod inserts than the FPCT did. No significant geometric distortion was detected in either modality. The FPCT was more prone to artifacts around Krischner wires with a diameter of 2 mm (P = 0.05-0.001), whereas the MDCT showed a higher amount of artifacts around wires with a diameter of 0.8 mm (P ≤ 0.001). Spatial resolution was 1 lp/mm (xy), 1.7 lp/mm (z) for the FPCT and 1 lp/mm (xy), less than 1 lp/mm (z) for the MDCT.
We compared a mobile FPCT and a 320-row MDCT by using the same radiation dose for scans. We found the spatial resolution to be higher in the FPCT. Hounsfield units were more accurate and homogeneity and contrast resolution were better in MDCT. The MDCT was also less prone to artifacts from thick Kirschner wires but showed comparably more artifacts around thin wires.
本研究旨在比较可进行四肢成像的紧凑型移动平板计算机断层扫描（FPCT）与相同辐射剂量下的多排计算机断层扫描（MDCT）的图像质量。
使用 FPCT 进行默认设置成像。使用蒙特卡罗模拟计算 320 排 MDCT 的等效剂量设置。模拟基于并通过剂量测量进行验证。在不同的成像体模中评估了均匀性、几何变形、伪影、亨氏单位值的准确性、对比度和空间分辨率。使用 Whitney-Mann U 检验和 Spearman ρ 进行统计分析。
FPCT 的均匀性达到 2.5%，MDCT 的均匀性达到 0.5%。MDCT 的亨氏单位值更准确，对比度与噪声比更高（P ≤ 0.001）。MDCT 比 FPCT 更能描绘出更多的棒状插入物。两种模式均未检测到明显的几何变形。FPCT 在直径为 2 毫米的 Krischner 导丝周围更容易出现伪影（P = 0.05-0.001），而 MDCT 在直径为 0.8 毫米的导丝周围显示出更高的伪影量（P ≤ 0.001）。FPCT 的空间分辨率为 1 lp/mm（xy）、1.7 lp/mm（z），MDCT 的空间分辨率为 1 lp/mm（xy）、小于 1 lp/mm（z）。
我们使用相同的辐射剂量对移动 FPCT 和 320 排 MDCT 进行了比较。我们发现 FPCT 的空间分辨率更高。MDCT 的亨氏单位值更准确，均匀性和对比度分辨率更好。MDCT 也较少受到粗克氏针的伪影影响，但显示出更明显的细导线伪影。
