Fast implementations of reconstruction-based scatter compensation in fully 3D SPECT image reconstruction
Fast implementations of reconstruction-based scatter compensation in fully 3D SPECT image reconstruction
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DOI：
10.1088/0031-9155/43/4/014
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发表时间：
1998-04-01
影响因子：
3.5
通讯作者：
Tsui, BMW
中科院分区：
文献类型：
--
作者：
Kadrmas, DJ;Frey, EC;Tsui, BMW
在SPECT中，可以通过对重建过程中的散射响应函数进行建模来实现精确的散射补偿。这种方法被称为基于重建的散射补偿(RBSC)。已经表明，与其他补偿散射的方法相比，RBSC具有许多优点，但是使用RBSC进行全3D补偿已经导致了令人望而却步的长重建时间。在这项工作中，我们提出了两种新的方法，可以与现有的方法结合使用，以实现显着减少RBSC重建时间。第一种方法是粗网格散布建模，它利用了散布以低频信息为主的特点，大大提高了散布模型的计算速度。第二种方法，间歇性RBSC，通过限制对散射进行建模的迭代次数来进一步加速重建过程。使用Te-99m示踪剂的3D MCAT模型的蒙特卡罗模拟实验以及使用TL-201示踪剂的实验数据对快速实现进行了评估。结果表明，这些快速方法可以在完全3D补偿的情况下重建与使用标准RBSC方法获得的图像非常相似的图像，并且重建时间缩短一个数量级。使用这些方法，使用RBSC的全3D迭代重建可以在临床真实时间的范围内很好地执行(××24图像重建在10分钟以内)。
Accurate scatter compensation in SPECT can be performed by modelling the scatter response function during the reconstruction process. This method is called reconstruction-based scatter compensation (RBSC). It has been shown that RBSC has a number of advantages over other methods of compensating for scatter, but using RBSC for fully 3D compensation has resulted in prohibitively long reconstruction times. In this work we propose two new methods that can be used in conjunction with existing methods to achieve marked reductions in RBSC reconstruction times. The first method, coarse-grid scatter modelling, significantly accelerates the scatter model by exploiting the fact that scatter is dominated by low-frequency information. The second method, intermittent RBSC, further accelerates the reconstruction process by limiting the number of iterations during which scatter is modelled. The fast implementations were evaluated using a Monte Carlo simulated experiment of the 3D MCAT phantom with Te-99m tracer, and also using experimentally acquired data with Tl-201 tracer. Results indicated that these fast methods can reconstruct, with fully 3D compensation, images very similar to those obtained using standard RBSC methods, and in reconstruction times that are an order of magnitude shorter. Using these methods, fully 3D iterative reconstruction with RBSC can be performed well within the realm of clinically realistic times (under 10 minutes for 64 x 64 x 24 image reconstruction).