多层螺旋CT诊断颅底骨折及其法医学应用价值

Application of multi-planar spiral CT to the practice of appraising fractures of skull base in forensic medical examinations

目的 比较多层螺旋CT三种重建方法在显示颅底骨折方面的差异,探讨其在法医学鉴定中的应用价值。方法 对40例颅脑外伤后怀疑颅底骨折的伤者进行多层螺旋CT扫描,然后将容积数据输入工作站进行横断面重建、多平面重建(MPR)和三维重建,三维重建采用表面显示法(SSD)。结果 24例颅前窝骨折,其中横断面显示骨折9例,MPR显示骨折24例,SSD显示9例;3组比较有显著性差异(P<0.001)。24例颅中窝骨折,横断面显示骨折15例,MPR显示骨折24例,SSD显示骨折4例;3组比较有显著性差异(P<0.001)。横断面重建和MPR均显示颅后窝骨折3例,两者无明显差异,SSD有1例显示。结论 SSD成像直观立体地显示了骨折的形态、走行、空间位置等情况,但对细小骨折显示不佳;多层螺旋CT检查可用于颅底骨折的法医学鉴定。

Objective To compare the differences between three kinds of reconstruction methods of the multi-planar spiral CT in diagnosing fractures of skull base , in order to appraise fractures of skull base in forensic medical examinations. Method 40 cases with suspicious basio-cranial fractures after cranio-cerebral trauma were examined by multi-planar spiral CT scanning. The data were imported into workstation for ax-ial scanning, multi-planar reconstruction (MPR) and 3D-reconstruction (using SSD). Results In 24 cases with anterior fossa fractures, 9 cases were found by axial scanning, 24 cases by MPR, 9 by SSD. The comparison between these groups showed significant statistical difference (P< 0.001). In the 24 cases with middle fossa factures, 15 were revealed by axial scanning, 24 by MPR, 4 cases by SSD. Likewise, the comparison between these three showed significant statistical difference (P< 0.001). Axial scanning and MPR equally displayed the 3 cases with fractures of posterior fossa, and there is no difference between them. Conclusion The image reconstructed by means of SSD could display the length, shape, and orienta-tion of the fracture line, the form, size and position of the bone fragments, as well as the manner of detach-ment of bone fragments. The joint application of axial scanning and MPR is the best approach for the exam-ination of skull base fractures; multi-planar spiral CT could be applied to evaluate skull base fractures in forennsic medical examinations.