Determination of mechanical and electronic shifts for pinhole SPECT using a single point source
Determination of mechanical and electronic shifts for pinhole SPECT using a single point source
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DOI：
10.1109/tmi.2004.842456
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发表时间：
2005-03-01
影响因子：
10.6
通讯作者：
Jaszczak, RJ
中科院分区：
文献类型：
--
作者：
Metzler, SD;Greer, KL;Jaszczak, RJ
未补偿的电子和机械位移的影响可能会影响针孔单光子发射计算机断层扫描的分辨率。通过模拟数据估计了无补偿漂移引起的分辨率下降。介绍了一种确定横向机械位移和轴向电子位移的方法，并对其进行了评价。该方法假定探测器的倾斜和旋转半径(ROR)是先前使用另一种方法确定的。当做出这一假设时，可以使用单个点源来确定其余的校准参数。前面已经描述了一种确定电子和机械位移以及倾斜度的方法；该方法需要三个点源。在大多数情况下，校准倾斜的频率远低于机械位移是合理的，因为倾斜是扫描仪的特性，而机械位移可以在每次更换准直器时改变。也可以使用另一种确定RoR的方法。最后，我们认为横向电子位移和焦距变化缓慢，并独立地找到了这些参数。
The effects of uncompensated electronic and mechanical shifts may compromise the resolution of pinhole single photon emission computed tomography. The resolution degradation due to uncompensated shifts is estimated through simulated data. A method for determining the transverse mechanical and axial electronic shifts is described and evaluated. This method assumes that the tilt of the detector and the radius of rotation (ROR) are previously determined using another method. When this assumption is made, it is possible to determine the rest of the calibration parameters using a single point source. A method that determines the electronic and mechanical shifts as well as the tilt has been previously described; this method requires three point sources. It may be reasonable in most circumstances to calibrate tilt much less frequently than the mechanical shifts since the tilt is a property of the scanner whereas the mechanical shift may change every time the collimator is replaced. An alternative method for determining the ROR may also be used. Lastly, we take the view that the transverse electronic shift and the focal length change slowly and find these parameters independently.