鼻区骨折MSCT图像后处理显示与诊断探讨

Post Processing of MSCT Images in Forensic Examination of Nasal and Paranasal Bone Fractures

目的探讨MSCT(Multi-slice spiral CT),图像后处理技术在鼻区骨折诊断中的应用价值。方法对120例疑有鼻区骨折的伤者行MSCT容积扫描,并采用骨算法及软组织算法薄层重建,在工作站上行多平面重组(MPR)、容积再现(VR)及最大密度投影(MIP)等后处理,观察有无骨折并判定其骨折类型。结果 120例患者中,MPR、VR及MIP诊断为不伴移位的线性骨折49例、24例、30例,诊断符合率分别为61.2%、80.0%、100%;MPR、VR及MIP诊断为伴移位的线性骨折30例、19例、22例,诊断符合率分别为73.3%、86.4%、100%;MPR、VR及MIP诊断为粉碎性骨折24例、19例、20例,诊断符合率分别为83.2%、95.0%、100%;MPR、VR及MIP诊断为伴上颌骨额突骨折17例、13例、15例,诊断符合率分别为88.2%、86.7%、100%。对于不伴移位和伴移位的线性骨折,MIP与MPR间的差异有统计学意义(P<0.05);对于不伴移位的线性骨折,MIP与VR间的差异亦有统计学意义(P<0.05)。结论 MSCT容积扫描及MPR、VR、MIP的联合应用对于判断有无鼻区骨折及骨折类型具有重要价值。MIP可以准确区分鼻骨缝、鼻骨孔和鼻区骨折,新鲜与陈旧性骨折要结合轴位图像及MPR综合评定。

Objective To investigate the application value of spiral CT post-processing techniques for examining nasal and paranasal bone fractures. Method 64-slice CT scanning of nasal area was performed in 120 trauma cases that were suspected as having nasal and paranasal bone fractures. The thin slice reconstruction with bone and soft tissue algorithm were also performed. The post-processing techniques including multi-plane reformation（MPR）, volume rending（VR） and maximum density projection（MIP） were carried out to demonstrate the fractures and their types. Results Using MPR, VR and MIP, the cases identified as linear nasal fractures without displacement were 49, 24 and 30 respectively, whose diagnostic accuracy was 61.2%, 80.0% and 100%; the cases identified as linear nasal fractures with displacement were 30,19 and 22 respectively, whose diagnostic accuracy was 73.3%, 86.4% and 100%; the cases identified as comminuted fractures were 24, 19 and 20 respectively, whose diagnostic accuracy was 83.2%, 95% and 100%; the cases identified as frontal process fractures were 17, 13 and 15 respectively, whose diagnostic accuracy was 88.2%, 86.7% and 100%. For linear nasal fractures with and without displacement, there was significant difference between MIP and MPR（P0.05）; for linear nasal fractures without displacement, there was also significant difference between MIP and VR（ P 0. 05）.Conclusion Multi-slice spiral CT volumetric scanning and combined application of MPR, VR and MIP were of important value for determining nasal fractures and fracture types. MIP can accurately distinguish the nasal bone hole, nasal suture and paranasal fractures.