多层螺旋CT图像后处理技术在评价脊柱金属内固定置入术中的应用

Application of Muti-Slice Spiral CT and Postprocessing Techniques in Evaluating the Metal Internal Fixator of Spine

目的应用CT多模后处理图像评价脊柱金属内固定装置植入的准确性,并探讨其临床应用价值。方法回顾性分析142例接受脊柱金属内固定置入术患者的临床和影像资料,所有患者均行X线平片和多层螺旋CT检查,对CT原始图像进行多平面重建(MPR)、容积再现(VR)和内固定支架透视成像,观察金属内固定装置显示效果及骨钉置入情况。结果 142个脊柱金属内固定装置、931枚金属骨钉均可以清晰地显示,图像质量优良,能够满足观察和测量要求。MPR能够清楚显示内固定物与周围组织的关系,但是有明显的金属伪影;VR可以立体地显示内固定物,但是骨钉观测受金属伪影干扰;骨骼内固定支架透视成像不受金属伪影影响,可以明显提高金属内固定评价的准确性。结论螺旋CT多模后处理图像能够清晰显示金属内固定装置及其与周围组织的关系,在脊柱金属内固定置入术的临床评价中具有较大的应用价值。

Objective To investigate the applicable value of spiral CT multi-model postprocessing techniques in evaluating the metal internal fixator after spinal operation through determaining the accuracy of implantation. Methods The clinical and imaging data of 142 patients with metal internal fixators in spine were analyzed retrospectively. X-ray plain and muti-slice spiral CT were performed in all patients, and multiplaner reformation（MPR）, vloume rendering（VR） and skeleton internal fixation fluoroscopy technique（SIFFT） were obtained by processing original images. The visual effect of metal internal fixator and the condition of bone nails were also observed. Results The total of 142 metal internal fixators and 931 metal bone nails were clearly displayed on MPR, VR and SIFFT images. The quality of images were superior and could meet demand of clinical observation and measurement. MPR clearly revealed metal internal fixators and peripheral tissues, but there were a lot of metal artifacts on MPR images. VR showed metal internal fixators stereoscopically, but a few metal artifacts disturbed observation of metal bone nails. SIFFT clearly displayed metal internal fixators without metal artifacts, and improved the accuracy of evaluation to metal internal fixator. Conclusion The spiral CT multi-model postprocessing images may clearly show metal internal fixator and peripheral tissues, and these postprocessing techniques are valuable to a great extent in evaluating metal internal fixator of spine.