Department of Medical Imaging, Jinling Hospital, Clinical School of Medical College, Nanjing University, Xuanwu District, Jiangsu Province, China.
Acad Radiol. 2011 Oct;18(10):1252-7. doi: 10.1016/j.acra.2011.05.009.
The purpose of this study was to optimize photon energy setting to reduce metal artifact of computed tomography (CT) images from implanted metal orthopedic devices in patients with fractures with monoenergetic imaging of dual-energy CT.
This study included 47 patients with factures who underwent metal orthopedic device implanting. After dual-energy CT scan, monoenergetic software was used to postprocess with the following six photon energies: 40 kiloelectron-voltage (keV), 70 keV, 100 keV, 130 keV, 160 keV, and 190 keV. Two radiologists evaluated and rated the reformatted images with six different photon energies and average weighted 120 kVp images according to 4-score scale. The Wilcoxon rank-sum test was used to compare image quality scores for total, internal, and external metal orthopedic devices. Interreader agreement for image quality scoring was calculated.
Monoenergetic imaging of dual-energy CT improved the quality of CT images in the fracture patients with metal orthopedic devices compared to the average weighted 120 kVp images for the total, external, and internal metal orthopedic devices (all P values < .01). Optimal keV setting with the lowest metal artifact was 130 keV for total, internal, and external metal orthopedic devices. Good interreader agreement was found for the evaluation of image quality for total, internal, and external metal orthopedic devices.
Monoenergetic imaging of dual-energy CT improves quality of CT images in patients with metal orthopedic devices after fracture. Reformatted images at 130 keV have the optimal quality for total, internal, and external metal orthopedic devices.
本研究旨在通过双能 CT 的单能量成像优化光子能量设置，以降低骨折伴内置金属骨科器械患者 CT 图像中的金属伪影。
本研究纳入 47 例骨折伴内置金属骨科器械的患者。在进行双能 CT 扫描后，使用单能量软件对以下 6 种光子能量进行后处理：40keV、70keV、100keV、130keV、160keV 和 190keV。两名放射科医生使用 6 种不同光子能量的重建图像和平均加权 120kVp 图像进行评分，并根据 4 分制进行评价。采用 Wilcoxon 秩和检验比较总、内、外金属骨科器械的图像质量评分。计算图像质量评分的读者间一致性。
与平均加权 120kVp 图像相比，双能 CT 的单能量成像改善了骨折伴内置金属骨科器械患者的 CT 图像质量，对总、外、内金属骨科器械均有统计学意义（均 P 值<.01）。总、内、外金属骨科器械的最佳 keV 设置为 130keV，金属伪影最低。总、内、外金属骨科器械的图像质量评价具有良好的读者间一致性。
双能 CT 的单能量成像可改善骨折伴内置金属骨科器械患者的 CT 图像质量。130keV 的重建图像具有总、内、外金属骨科器械的最佳质量。
