Inversion of the 3D Radon transform for a multidetector, point-focused SPECT brain scanner.
Inversion of the 3D Radon transform for a multidetector, point-focused SPECT brain scanner.
复制标题
多探测器、点聚焦 SPECT 脑扫描仪的 3D Radon 变换反演。
DOI：
10.1088/0031-9155/31/3/001
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发表时间：
1986
影响因子：
3.5
通讯作者：
S. P. Mueller
中科院分区：
文献类型：
--
作者：
S. Moore;S. P. Mueller
Radon 变换适用于使用多探测器、点聚焦 SPECT 脑扫描仪采集的未衰减投影数据。三维 (3D) 积分变换仅在理想机器的情况下是完全可逆的，该理想机器的探测器从源向所有方向扫描到无穷远。先前用于该扫描仪的二维 (2D) 斜坡滤波器重建算法是 3D 方法的极限情况，并且仅对于具有柱对称性的源是精确的（对于所有 z，f(x,y,z) = f(x,y)）。来自相同直径和活性浓度的长圆柱体和 1.5 厘米厚圆盘的投影数据通过计算机模拟，以用于机器上使用的相同扫描模式。使用 2D 和 3D 分析方法重建数据。 2D 方法在椎间盘中心产生 20% 的碗形凹陷，而 3D 重建的中心切片的准确度超过 97%。使用必要的 3D 方法重建椎间盘中心切片时的有效噪声等效灵敏度比使用 2D 方法重建时针对长圆柱形源获得的灵敏度低 10.1 倍。
The Radon transform is presented for unattenuated projection data acquired with a multidetector, point-focused SPECT brain scanner. The three-dimensional (3D) integral transform is shown to be exactly invertible only for the case of an ideal machine whose detectors scan away from the source to infinity in all directions. The two-dimensional (2D) ramp filter reconstruction algorithm previously used for this scanner is a limiting case of the 3D method and is exact only for sources with cylindrical symmetry, (f(x,y,z) = f(x,y) for all z). Projection data from a long cylinder and a 1.5 cm thick disc of equal diameters and activity concentrations were simulated by computer for the same scan pattern used on the machine. The data were reconstructed with both the 2D and 3D analytic methods. The 2D method produced a 20% bowl-shaped dip in the centre of the disc, whereas the central slice of the 3D reconstruction was more than 97% accurate. The effective, noise-equivalent sensitivity when reconstructing the central slice of the disc with the necessary 3D method is 10.1 times lower than the sensitivity obtained for the long cylindrical source when reconstructing with the 2D method.