-
1.发明授权Computer tomography apparatus including a combined recursive and convolution filter 失效计算机断层摄影装置包括组合递归和卷积滤波器
公开(公告)号：US4761738A
公开(公告)日：1988-08-02
申请号：US884453
申请日：1986-07-11
CPC分类号： G06T11/005 , Y10S378/901
摘要： In a computer tomography apparatus in accordance with the invention the advantages of the convolution calculation are combined with the advantages of recursive filtering. The processing unit for the measurement data includes a convolution filter which has only 64 convolution factors and which performs the central part of a convolution calculation (the number of measurement data amounts to, for example 512 or 1024) and a parallel-operating recursive filter which approximates the rests of the convolution calculation situated outside the central part by recursive filtering of the measurement data. Using five different multiplication factors and a corresonding number of attenuation factors, ample accuracy is achieved. By variable of only the 64 convolution factors, a large number of different filters can be realized, without it being necessary to change the factors for recursive filtering.
-
2.发明授权Method and computer tomography device for determining a tomographic image with elevated resolution 失效用于以升高的分辨率确定断层图像的方法和计算机断层摄影装置
公开(公告)号：US4555760A
公开(公告)日：1985-11-26
申请号：US491516
申请日：1983-05-04
CPC分类号： G06T11/006 , G06T2211/421 , Y10S378/901
摘要： A computer tomography device, in which the row of detectors has been rotated through the quarter of a detector angle (.DELTA..psi./4) with respect to the X-ray source. The invention filters selected parallel measurement values which were measured in a single direction instead of doing so with all the selected measurement values measured in parallel and antiparallel directions. The calculating time required for filtering is reduced by a factor of 2 and the values can be pipeline processed.
摘要翻译： 一种计算机断层摄影装置，其中检测器行已经相对于X射线源旋转了四分之一的检测器角度（DELTA psi / 4）。 本发明过滤所选择的并行测量值，该测量值是在单个方向上测量的，而不是以并行和反向平行方向测量的所有所选测量值进行测量。 滤波所需的计算时间减少了2倍，并且可以对流水线进行处理。
-
公开(公告)号：US4549265A
公开(公告)日：1985-10-22
申请号：US465936
申请日：1983-02-14
CPC分类号： G06T11/006 , G06T2211/421 , Y10S378/901
摘要： A method and device for computer tomography in which the same filtering operation can be performed for the image reconstruction, regardless of the method used to measure the measured data. Before and after the filtering the data there is performed a multiplication by a pre-conditioning factor and a post-conditioning factor, respectively. The pre-conditioning and post-conditioning factors are dependent on the type of reconstruction and on the position of a data in the group of measured data. The fact that the same filter can be used is important notably for computer tomography apparatus in which a convolution filter is embodied in circuit hardware. The back-projection device is suitable for the back-projection of measured data along diverging measuring paths as well as measured data along parallel measuring paths with only modification of some constants.
摘要翻译： 用于计算机断层摄影的方法和装置，其中可以对图像重建执行相同的滤波操作，而不管用于测量测量数据的方法如何。 在过滤数据之前和之后，分别进行预处理因子和后处理因子的乘法。 预处理和后处理因素取决于重建的类型和数据在测量数据组中的位置。 可以使用相同的滤波器的事实对于其中卷积滤波器体现在电路硬件中的计算机断层摄影装置是重要的。 背投影装置适用于沿着发散测量路径的测量数据的反投影以及沿着并行测量路径的测量数据，仅修改了一些常数。
-
4.发明授权Method of and device for determining a radiation absorption distribution in a part of a body 失效用于确定身体部位的辐射吸收分布的方法和装置
公开(公告)号：US4460961A
公开(公告)日：1984-07-17
申请号：US73572
申请日：1979-09-07
CPC分类号： A61B6/032 , A61B6/5205 , G06T11/006 , Y10S378/901
摘要： The invention relates to a method of and a device for determining a radiation absorption distribution in a part of a body. Per measuring value a contribution of the absorption value in each element of a matrix imagined in the part is calculated. It is demonstrated that this contribution equals the value of the measuring value multiplied by a weighting factor. The weighting factor is a function of the distance between the element and the measuring path along which the measuring value is determined. A calculation method of this kind enables fast on-line calculation of an absorption distribution and the complete reconstruction of the absorption distribution is laid down in a hardware circuit. Complex operations such as F.F.T., convolution and interpolation are not required.
摘要翻译： 本发明涉及一种用于确定身体的一部分中的辐射吸收分布的方法和装置。 每个测量值计算在该部分中想象的矩阵的每个元素中的吸收值的贡献。 证明这个贡献等于测量值乘以加权因子的值。 加权系数是测量值确定的元件与测量路径之间的距离的函数。 这种计算方法能够快速地在线计算吸收分布，并且在硬件电路中规定了吸收分布的完全重建。 不需要诸如F.F.T.之类的复杂操作，卷积和插值。
-
-
-
搜索结果
4 条记录 (耗时 0.019 秒)
