Medical Imaging Centre of Southwest Finland, Turku University Hospital, Kiinamyllynkatu 4-8, 20520, Turku, Finland,
Skeletal Radiol. 2013 Nov;42(11):1507-13. doi: 10.1007/s00256-013-1692-6. Epub 2013 Aug 3.
To evaluate parameters and positioning when imaging total ankle prostheses on computed tomography (CT).
An ankle prosthesis implanted into a pig's knee joint underwent 16 different CT imaging protocols. Four defects were drilled around prosthesis components simulating periprosthetic osteolytic lesions. The specimen with the implant was imaged in four different orientations with the tibial stem parallel to the table and at 25, 45, and 90° angles to it. The protocol consisted of scanning at 100, 120, and 140 kVp in every position with a pitch of 1.2. The scanning at 120 kVp in every position was repeated with a pitch of 1.0.
CT proved to be a reliable imaging modality when studying periprosthetic lesions adjacent to the ankle prosthesis when the tibial stem alignment was parallel to the table. When imaging at higher angles, metal artifacts distorted the image, making the analysis of periprosthetic bone structure unreliable. There were no statistically significant differences between different tube voltages or pitch in volume measurements of the osteolytic lesions.
CT is a reliable imaging method to evaluate periprosthetic bone structure around ankle prostheses when orientation of the prosthesis and acquisition parameters is optimized.
评估在计算机断层扫描（CT）上对全踝关节假体成像的参数和定位。
将植入猪膝关节的踝关节假体进行了 16 种不同的 CT 成像方案。在假体周围模拟假体周围溶骨性病变的情况下，在假体组件周围钻了四个缺陷。将带有植入物的标本以胫骨柄与台面平行和与胫骨柄成 25、45 和 90°的四个不同方向进行成像。该方案包括在每个位置以 100、120 和 140 kVp 扫描，每个位置的螺距为 1.2。在每个位置以 120 kVp 重复扫描，螺距为 1.0。
当胫骨柄与台面平行时，CT 被证明是研究踝关节假体附近假体周围病变的可靠成像方式。当以更高的角度成像时，金属伪影会扭曲图像，使得对假体周围骨结构的分析不可靠。在骨溶解病变的体积测量中，不同的管电压或螺距之间没有统计学上的显著差异。
当优化假体的方向和采集参数时，CT 是评估踝关节假体周围假体周围骨结构的可靠成像方法。
