长管状骨骨折移位X线表现的校正方法探讨

The study on the X-ray correction method of long bone fracture displacement

目的探讨常规X线摄影（正、侧位）时骨折移位影像表现的校正方法，并用CT验证。方法根据X线摄影几何学原理设计出移位的校正方法。取一枚中段骨折的肱骨标本构成一定程度的侧方移位和成角移位后，将标本沿横轴多角度旋转并分别行前后（正位）、左右（侧位）方向X线拍摄，然后利用CT进行整个标本的容积扫描，并将容积扫描数据进行多维平面重建（MPR）及表面遮盖显示（SSD）。对X线图像的移位程度及校正数据、MPR及SSD后的移位程度、标本实际移位程度分别进行比较分析。结果经X线图像求得的校正数据、MPR及SSD后所得的数据与标本实际设置移位方向、程度误差较小，位置差异〈1．5mm，角度差异〈1.5°。结论常规X线摄影显示的骨折移位的影像表现经坐标图测量校正，方法真实可靠，可以显著提高X线诊断骨折移位程度的准确性。

Objective To explore the image correction of fracture displacement by conventional X-ray photography（orthotropie and lateral） and test by computed tomgraphy（CT）. Methods The correction method of fracture displacement was designed according to geometry principles of X-ray photography. Selected one midhumeral fracture specimen which designed with lateral shift and angular displacement,and scanned from anteroposterior and lateral position respectively, and also volume scanned using CT, the data obtained from volume scan were processed using muhiplanar reconstruction （MPR） and shaded surface display （SSD）. The displacement data relied on X-ray image, CT with MPR and SSD processing, actual design of specimens were compared respectively. Result The direction and degree of displacement among correction data of X-ray images and the data from MPR and SSD, actual design of specimen were little difference, location difference〈 1.5 mm, degree difference〈 1.5°. Conclusion It is really reliable for fracture displacement by conventional X-ray photography with coordinate correction, and it is helpful to obviously improve the diagnostic accuracy of the degree of fracture displacement.