Objectives: To compare the application value of three image post-processing techniques volume rendering (VR), multiplanar reformation (MPR) and curved planar reformation (CPR) in the identification of rib fracture malunion.
Methods: The types and numbers of rib fracture malunion in 75 patients were recorded, and the sensitivity, specificity, accuracy and Youden index of VR, MPR and CPR in the diagnosis of rib fracture malunion were compared. Receiver operator characteristic (ROC) curve was drawn and area under the curve (AUC) was calculated, and the detection rates of three image post-processing techniques for different types of rib fracture malunion were compared.
Results: A total of 243 rib fractures were malunion in 75 patients. The diagnostic sensitivity of VR, MPR and CPR for rib fracture malunion was 52.67%, 79.84% and 91.36%, the specificity was 99.58%, 97.89% and 99.15%, the accuracy was 83.66%, 91.76% and 96.51%, the Youden index was 0.52, 0.78 and 0.91, the AUC was 0.761, 0.889 and 0.953, respectively. Compared with VR, there were statistically significant differences in the number of broken rib end misalignment over 1/3, broken rib end overlap, broken rib end angulation and intercostal bridge detected in MPR (P<0.05). Compared with VR, there was a statistically significant difference in the number of different types of rib fracture malunion detected by CPR (P<0.05). Compared with MPR, there were statistically significant differences in the number of broken rib end misalignment over 1/3, broken rib end separation and intercostal bridge detected in CPR (P<0.05).
Conclusions: The three image post-processing techniques are of great significance for the identification of rib fracture malunion. Especially CPR is highly effective in the diagnosis of rib fracture malunion, and can be used as the main post-processing technique for forensic clinical identification of rib fracture malunion.
目的: 比较容积再现（volume rendering，VR）、多平面重组（multiplanar reformation，MPR）和曲面重组（curved planar reformation，CPR） 3种图像后处理技术在肋骨骨折畸形愈合认定中的应用价值。方法: 记录75例患者肋骨骨折畸形愈合的类型及数量，比较VR、MPR、CPR对肋骨骨折畸形愈合诊断的灵敏度、特异度、准确率和约登指数，绘制受试者操作特征（receiver operator characteristic，ROC）曲线并计算曲线下面积（area under the curve，AUC），比较3种图像后处理技术对不同类型肋骨骨折畸形愈合的检出率。结果: 75例患者共有243处肋骨骨折畸形愈合。VR、MPR、CPR对肋骨骨折畸形愈合诊断的灵敏度分别为52.67%、79.84%、91.36%，特异度分别为99.58%、97.89%、99.15%，准确率分别为83.66%、91.76%、96.51%，约登指数分别为0.52、0.78、0.91，AUC分别为0.761、0.889、0.953。与VR相比，MPR在断端错合1/3以上、断端重叠、断端成角、骨桥的检出数量上差异有统计学意义（P<0.05）；与VR相比，CPR在肋骨骨折畸形愈合各分型的检出数量上差异有统计学意义（P<0.05）；与MPR相比，CPR在断端错合1/3以上、断端分离、骨桥的检出数量上差异有统计学意义（P<0.05）。结论: 3种图像后处理技术对肋骨骨折畸形愈合的认定均具有重要意义，尤其是CPR对肋骨骨折畸形愈合的诊断效能高，可作为肋骨骨折畸形愈合法医临床鉴定的主要后处理技术。.
Keywords: curved planar reformation; forensic medicine; malunion of fracture; multiplanar reformation; rib fracture; volume rendering.