Influence of Doppler broadening model accuracy in Compton camera list-mode MLEM reconstruction

IF 1.1 4区工程技术 Q3 ENGINEERING, MULTIDISCIPLINARY

Inverse Problems in Science and Engineering Pub Date : 2021-12-12 DOI:10.1080/17415977.2021.2011863

Yuemeng Feng, J. Létang, D. Sarrut, Voichia Maxim

引用次数: 10

Abstract

The Compton camera is a gamma ray imaging device expected to provide clinically relevant images in the SPECT applications where collimated cameras are sub-optimal. Its imaging performances depend not only on the design of the detection system but also on choices related to tomographic reconstruction. The aim of this work is to show that the accuracy in modelling the acquisition largely influences the quality of the images. For this purpose, we restrict here to Doppler broadening models in conjunction with the list-mode maximum likelihood expectation maximization (LM-MLEM) algorithm. The study was carried out with Monte-Carlo simulation. We show that the reconstructed point spread function is location-dependent when the model is not accurate, and the usual elongation artefacts well-known in Compton camera imaging will appear. The model we propose allows us to reconstruct isolated point sources and more complex non-uniform sources with improved resolution even in the direction orthogonal to the camera.

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多普勒展宽模型对康普顿相机表模MLEM重建精度的影响

康普顿相机是一种伽马射线成像设备，有望在SPECT应用中提供临床相关的图像，其中准直相机是次优的。其成像性能不仅取决于检测系统的设计，还取决于与层析重建相关的选择。这项工作的目的是表明，在建模采集的准确性在很大程度上影响图像的质量。为此，我们在此将多普勒展宽模型与列表模式最大似然期望最大化(LM-MLEM)算法结合使用。采用蒙特卡罗模拟方法进行了研究。结果表明，当模型不精确时，重构的点扩散函数是位置依赖的，并且会出现康普顿相机成像中常见的伸长伪影。我们提出的模型使我们能够重建孤立的点源和更复杂的非均匀源，即使在与相机正交的方向上也能提高分辨率。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Inverse Problems in Science and Engineering 工程技术-工程：综合

自引率

0.00%

发文量

审稿时长

6 months

期刊介绍： Inverse Problems in Science and Engineering provides an international forum for the discussion of conceptual ideas and methods for the practical solution of applied inverse problems. The Journal aims to address the needs of practising engineers, mathematicians and researchers and to serve as a focal point for the quick communication of ideas. Papers must provide several non-trivial examples of practical applications. Multidisciplinary applied papers are particularly welcome. Topics include: -Shape design: determination of shape, size and location of domains (shape identification or optimization in acoustics, aerodynamics, electromagnets, etc; detection of voids and cracks). -Material properties: determination of physical properties of media. -Boundary values/initial values: identification of the proper boundary conditions and/or initial conditions (tomographic problems involving X-rays, ultrasonics, optics, thermal sources etc; determination of thermal, stress/strain, electromagnetic, fluid flow etc. boundary conditions on inaccessible boundaries; determination of initial chemical composition, etc.). -Forces and sources: determination of the unknown external forces or inputs acting on a domain (structural dynamic modification and reconstruction) and internal concentrated and distributed sources/sinks (sources of heat, noise, electromagnetic radiation, etc.). -Governing equations: inference of analytic forms of partial and/or integral equations governing the variation of measured field quantities.