Soussaline F P, Cao A, Le Coq G, Raynaud C, Kellershohn C
Eur J Nucl Med. 1982;7(11):487-93. doi: 10.1007/BF00257213.
The problem of transverse plane reconstruction from an ensemble of projections is considered in its general formulation and an analytically exact solution to the attenuated tomographic operator is proposed. Such a technique, called the regularizing iterative method (RIM), allows the introduction of a priori knowledge on the size and shape of the activity distribution and in principle on the exact attenuation distribution. The relaxation factor used is so named because it provides noise filtering for a small number of iterations. The effectiveness of RIM was studied in the single photon emission computed tomography (SPECT) problem with the aim of correcting for attenuation before quantitative study. Its application involves the use of a rotating scintillation camera connected to a mini-computer system. Various mathematical and physical phantoms were studied, and a satisfactory attenuation correction was always obtained in the final image with an improvement in the contrast and signal-to-noise ratio. Preliminary clinical studies on liver transverse sections seems to indicate an improvement in deep lesion detectability, compared with images obtained by the filtered (Ramp) back projection technique.
从投影集合进行横断面重建的问题在其一般形式下得到了考虑，并提出了对衰减断层扫描算子的解析精确解。这种技术称为正则化迭代法（RIM），它允许引入关于活动分布的大小和形状以及原则上关于精确衰减分布的先验知识。所使用的松弛因子之所以如此命名，是因为它在少量迭代中提供噪声滤波。为了在定量研究之前校正衰减，在单光子发射计算机断层扫描（SPECT）问题中研究了RIM的有效性。它的应用涉及使用连接到小型计算机系统的旋转闪烁相机。研究了各种数学和物理模型，并且在最终图像中总是获得令人满意的衰减校正，同时对比度和信噪比得到改善。与通过滤波（斜坡）反投影技术获得的图像相比，对肝脏横断面的初步临床研究似乎表明深部病变的可检测性有所提高。
