Abstract：
This study aims to compare a relatively novel three-dimensional rendering called Path Tracing (PT) to the Volume Rendering technique (VR) in the post-surgical assessment of head and neck oncologic surgery followed by bone flap reconstruction. This retrospective study included 39 oncologic patients who underwent head and neck surgery with free bone flap reconstructions. All exams were acquired using a 64 Multi-Detector CT (MDCT). PT and VR images were created on a dedicated workstation. Five readers, with different expertise in bone flap reconstructive surgery, independently reviewed the images (two radiologists, one head and neck surgeon and two otorhinolaryngologists, respectively). Every observer evaluated the images according to a 5-point Likert scale. The parameters assessed were image quality, anatomical accuracy, bone flap evaluation, and metal artefact. Mean and median values for all the parameters across the observer were calculated. The scores of both reconstruction methods were compared using a Wilcoxon matched-pairs signed rank test. Inter-reader agreement was calculated using Spearman\'s rank correlation coefficient. PT was considered significantly superior to VR 3D reconstructions by all readers (p < 0.05). Inter-reader agreement was moderate to strong across four out of five readers. The agreement was stronger with PT images compared to VR images. In conclusion, PT reconstructions are significantly better than VR ones. Although they did not modify patient outcomes, they may improve the post-surgical evaluation of bone-free flap reconstructions following major head and neck surgery.
摘要：
这项研究旨在比较一种相对新颖的三维渲染，称为路径追踪（PT）与体积渲染技术（VR），用于头颈部肿瘤外科术后评估，然后进行骨瓣重建。这项回顾性研究包括39例接受头颈部手术和游离骨瓣重建的肿瘤患者。所有检查均使用64多探测器CT（MDCT）进行。PT和VR图像是在专用工作站上创建的。五个读者在骨瓣重建手术方面有不同的专业知识，独立审查了图像(两名放射科医生，一名头颈外科医师和两名耳鼻喉科医师,分别)。每个观察者根据5点Likert量表评估图像。评估的参数是图像质量，解剖学准确性，骨瓣评估，和金属人工制品。计算整个观察者的所有参数的平均值和中值。使用Wilcoxon匹配对符号秩检验比较了两种重建方法的得分。使用Spearman的等级相关系数计算读者间的一致性。所有读者都认为PT明显优于VR3D重建（p<0.05）。在五分之四的读者中，读者间的协议是中等到强的。与VR图像相比，PT图像的一致性更强。总之,PT重建明显优于VR重建。尽管他们没有改变患者的预后，它们可以改善头颈部大手术后无骨瓣重建的术后评估.
