Asl Mahsa Noori, Sadremomtaz Alireza, Bitarafan-Rajabi Ahmad
Department of Physics, Faculty of Sciences, University of Guilan, Rasht, Iran.
Department of Nuclear Medicine, Rajaei Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
J Med Phys. 2013 Oct;38(4):189-97. doi: 10.4103/0971-6203.121197.
Compton-scattered photons included within the photopeak pulse-height window result in the degradation of SPECT images both qualitatively and quantitatively. The purpose of this study is to evaluate and compare six scatter correction methods based on setting the energy windows in (99m)Tc spectrum. SIMIND Monte Carlo simulation is used to generate the projection images from a cold-sphere hot-background phantom. For evaluation of different scatter correction methods, three assessment criteria including image contrast, signal-to-noise ratio (SNR) and relative noise of the background (RNB) are considered. Except for the dual-photopeak window (DPW) method, the image contrast of the five cold spheres is improved in the range of 2.7-26%. Among methods considered, two methods show a nonuniform correction performance. The RNB for all of the scatter correction methods is ranged from minimum 0.03 for DPW method to maximum 0.0727 for the three energy window (TEW) method using trapezoidal approximation. The TEW method using triangular approximation because of ease of implementation, good improvement of the image contrast and the SNR for the five cold spheres, and the low noise level is proposed as most appropriate correction method.
包含在光电峰脉冲高度窗口内的康普顿散射光子会导致单光子发射计算机断层扫描（SPECT）图像在定性和定量方面的退化。本研究的目的是评估和比较基于在（99m）Tc能谱中设置能量窗口的六种散射校正方法。使用SIMIND蒙特卡罗模拟从冷球热背景体模生成投影图像。为了评估不同的散射校正方法，考虑了三个评估标准，包括图像对比度、信噪比（SNR）和背景相对噪声（RNB）。除了双光电峰窗口（DPW）方法外，五个冷球的图像对比度在2.7%至26%的范围内得到改善。在所考虑的方法中，有两种方法显示出不均匀的校正性能。所有散射校正方法的RNB范围从DPW方法的最小值0.03到使用梯形近似的三能量窗口（TEW）方法的最大值0.0727。由于易于实现、五个冷球的图像对比度和SNR有良好改善以及噪声水平低，使用三角形近似的TEW方法被提议为最合适的校正方法。
