背景:使用锥形束CT(CBCT)的术中3D成像可改善对植入物位置的评估并减少脊柱手术的并发症。它也用于图像引导的手术技术,从而提高护理质量。然而,在某些情况下,金属伪影可降低图像质量,使其难以评估椎弓根螺钉的位置和复位。
目的:本研究的目的是研究在背侧器械期间CBCT采集轨迹与椎弓根螺钉位置的关系是否可以减少金属伪影,从而提高图像质量和临床评估能力。
方法:实验尸体研究方法::在胸椎和腰椎区域(Th11至L5)对人类尸体进行椎弓根螺钉固定。然后,CBCT的采集轨迹(CiosSpin,西门子,德国)以5°的角度(-30°至30°)和旋转(-25°至25°)系统地改变了椎弓根螺钉。随后,放射学评估由三个盲区进行,使用9个问题(包括解剖结构,植入物位置,伪影的外观)得分(1-5分)。对于统计评估,将不同采集轨迹的图像质量与标准采集轨迹进行比较,并检查是否存在显著差异.
结果:成角度的采集轨迹显着提高了主观图像质量评分(p<0.001)以及椎弓根螺钉位置的临床评估能力(p<0.001),对椎弓根区域的主观图像质量影响特别大(d=1.61)。采集轨迹的旋转显着改善了所有查询域的主观图像质量(p<0.001)以及椎弓根螺钉位置的临床评估能力(p<0.001)。
结论:在这项尸体研究中,在具有恒定等中心的术中3D成像(CBCT)中,采集轨迹的角度和旋转导致图像质量显著提高.数据显示,朝向30°/25°最大化角度/旋转角度提供了最佳的测试主观图像质量并增强了临床可评估性。因此,正确调整采集轨迹有助于更可靠地做出术中翻修决策.
结论:通过改变术中3D成像中的采集轨迹来增强图像质量的知识可用于评估脊柱手术中的关键螺钉位置。这些知识的实施仅需要对当前术中成像工作流程进行微小改变,而无需额外的技术设备,并且可以进一步减少对翻修手术的需求。
BACKGROUND: Intraoperative 3D imaging with cone-beam CT (CBCT) improves assessment of implant position and reduces complications in spine surgery. It is also used for image-guided surgical techniques, resulting in improved quality of care. However, in some cases, metal artifacts can reduce image quality and make it difficult to assess pedicle screw position and reduction.
OBJECTIVE: The objective of this study was to investigate whether a change in CBCT acquisition trajectory in relation to pedicle screw position during dorsal instrumentation can reduce metal artifacts and consequently improve image quality and clinical assessability.
METHODS: Experimental cadaver study METHODS: : A human cadaver was instrumented with pedicle screws in the thoracic and lumbar spine region (Th11 to L5). Then, the acquisition trajectory of the CBCT (Cios Spin, Siemens, Germany) to the pedicle screws was systematically changed in 5° steps in angulation (-30° to +30°) and swivel (-25° to +25°). Subsequently, radiological evaluation was performed by three blinded, qualified raters on image quality using 9 questions (including anatomical structures, implant position, appearance of artifacts) with a score (1-5 points). For statistical evaluation, the image quality of the different acquisition trajectories was compared to the standard acquisition trajectory and checked for significant differences.
RESULTS: The angulated acquisition trajectory significantly increased the score for subjective image quality (p<0.001) as well as the clinical assessability of pedicle screw position (p<0.001) with particularly strong effects on subjective image quality in the vertebral pedicle region (d=1.61). Swivel of the acquisition trajectory significantly improved all queried domains of subjective image quality (p<0.001) as well as clinical assessability of pedicle screw position (p<0.001).
CONCLUSIONS: In this cadaver study, the angulation as well as the swivel of the acquisition trajectory led to a significantly improved image quality in intraoperative 3D imaging (CBCT) with a constant isocenter. The data show that maximizing the angulation/swivel angle towards 30°/25° provides the best tested subjective image quality and enhances clinical assessability. Therefore, a correct adjustment of the acquisition trajectory can help to make intraoperative revision decisions more reliably.
CONCLUSIONS: The knowledge of enhanced image quality by changing the acquisition trajectory in intraoperative 3D imaging can be used for the assessment of critical screw positions in spine surgery. The implementation of this knowledge requires only a minor change of the current intraoperative imaging workflow without additional technical equipment and could further reduce the need for revision surgery.