Joseph P M, Spital R D
J Comput Assist Tomogr. 1978 Jan;2(1):100-8. doi: 10.1097/00004728-197801000-00017.
A method that corrects for artifacts in X-ray transmission scanners created by the alteration of the energy spectrum by bone is described. The method involves two reconstructions of the pictures: the first establishes the approximate distribution of bone and the second enables the artifacts to be eliminated. The first reconstruction is needed to establish the total amount of bone along each ray. Assuming that the X-ray energy spectrum is known, it is shown how the line integrals can be corrected. The method was tested on several mathematical phantoms as well as on human head data. The nonlinear nature of the spectral artifacts is shown to produce streaks in certain phantoms.
描述了一种校正X射线透射扫描仪中由骨骼改变能谱而产生的伪影的方法。该方法涉及对图像进行两次重建：第一次重建确定骨骼的大致分布，第二次重建则用于消除伪影。需要进行第一次重建以确定沿每条射线的骨骼总量。假设X射线能谱已知，展示了如何对线积分进行校正。该方法在几个数学模型以及人体头部数据上进行了测试。结果表明，光谱伪影的非线性性质会在某些模型中产生条纹。
