全脊柱无伪影X线数字摄影研究

Study on digital radiography without artifacts for whole spine

目的:探讨一种获取无伪影全脊柱X线数字化图像的方案,以确保Cobb角的测量精度。方法:搭建一个以长60 cm的X线增感屏和单反数码相机为基础的新的数字成像装置,用该装置和直接数字化放射摄影(direct digital radiography,DDR)系统分别拍摄分辨率测试卡的X线图像并比较。结果:新装置的空间分辨率为1.6 LP/mm,接近DDR系统的空间分辨率,但其对比度分辨率明显低于DDR系统。结论:该数字成像装置只需一次X线曝光、不用图像拼接就直接得到全脊柱数字化X线图像,避免了伪影的产生,可保证Cobb角的测量精度。

Objective To explore a scheme of digital radiography without artifacts for whole spine in order to ensure the accuracy in Cobb angle measurement. Methods A new digital imaging device was fabricated based on a digital single lens reflex camera（DSLR） and a long X-ray intensifying screen of 60 cm. The X-ray images of a resolution test module taken with the device and direct digital radiography（DDR） system were compared. Results The spatial resolution of the digital imaging device was close to that of the DDR system with the value of 1.6 LP/mm, but its contrast resolution was far lower than that of the DDR system. Conclusion The digital imaging device can get a full-spine radiographic picture with only one short X-ray exposure but without any stitching process which produces artifacts, thus can ensure the accuracy in measuring Cobb angle.