IEEE Trans Med Imaging. 2015 Mar;34(3):788-95. doi: 10.1109/TMI.2014.2361680. Epub 2014 Oct 9.
Material basis decomposition in the sinogram domain requires accurate knowledge of the forward model in spectral computed tomography (CT). Misspecifications over a certain limit will result in biased estimates and make quantum limited (where statistical noise dominates) quantitative CT difficult. We present a method whereby users can determine the degree of allowed misspecification error in a spectral CT forward model and still have quantification errors that are limited by the inherent statistical uncertainty. For a particular silicon detector based spectral CT system, we conclude that threshold determination is the most critical factor and that the bin edges need to be known to within 0.15 keV in order to be able to perform quantum limited material basis decomposition. The method as such is general to all multibin systems.
在能谱 CT 中，体素域的材料分解需要精确的正向模型知识。如果超过一定的限制，模型的不精确会导致有偏的估计，使得量子受限（统计噪声起主导作用）定量 CT 变得困难。我们提出了一种方法，用户可以用此方法确定光谱 CT 正向模型中允许的不精确误差程度，并且量化误差仍然受到固有统计不确定性的限制。对于特定的基于硅探测器的光谱 CT 系统，我们得出结论，阈值确定是最关键的因素，为了能够进行量子受限的材料分解，需要将 bin 边缘的精度控制在 0.15keV 以内。这种方法对于所有多 bin 系统都是通用的。
