Development of a software for nonounifrom attenuation and scatter correction in SPECT using XCT data

使用 XCT 数据开发 SPECT 中非均匀衰减和散射校正软件

• 批准号: 05557045
• 负责人: SUZUKI Shigehito
• 金额: $ 2.37万
• 依托单位: Kitami Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-05557045/
• 关键词: SPECT; Attenuation and scatter correction; Nonunifrom medium

1. Design of algorithm for nonunifrom attenuation correction in SPECT using x-ray CT image data(1) Construction of the algorithm.Three kinds of the algorithm were constructed which are based on three methods reported by Chang, Tanaka, and Singh.The first two had originally been proposed for uniform attenuation correction, but in the algorithm they were modified for nonunifrom attenuation correction.From computer experiments, it was found that their first-order correction did not produce good correction results, but their second-order correction gave satisfactory resulsts only with a single iteration.(2) Problems in clinical applications.Two major problems were found : the coincidence of anatomical positions between XCT image and the corresponding uncorrected image for SPECT,and the determination of average X-ray energy for the XCT image.This information is used when converting attenuation data for XCT to those attenuation for SPECT.A solution for the problems is the key to accurate attenuation correction in clinical applications.2. Scatter correctionA theoretical evaluation of scattered radiation in detected photons was planned primarily, but its application to individual SPECT images was not practical in computation time.It was concluded that a practically promising method for accurate scatter correction is to evaluate scattered radiation from photon counts detected with plural energy windows.More detailed studies of this subject are being carried out.

1.利用X射线CT图像数据的SPECT非均匀衰减校正算法的设计（1）算法的构造：基于Chang，Tanaka和Singh提出的三种方法，构造了三种算法。前两种算法最初是针对均匀衰减校正提出的，但在算法中对它们进行了修改，以用于非均匀衰减校正。计算机实验表明，结果表明，它们的一阶修正效果不好，而二阶修正只需一次迭代就能得到满意的结果。(2)临床应用中存在的问题：XCT图像与SPECT未校正图像之间解剖位置的一致性和XCT图像平均X射线能量的确定是XCT衰减数据转换为SPECT衰减数据时需要考虑的两个主要问题，解决这些问题是临床应用中准确校正衰减的关键.散射校正最初计划对探测到的光子中的散射辐射进行理论评估，但其应用于单个SPECT图像在计算时间上并不实用。得出的结论是，一种实用的有希望的精确散射校正方法是从多能量窗口探测到的光子计数中评估散射辐射。正在进行更详细的研究。

项目成果

鈴木 茂人: "X線CTデータを利用したSPECT不均一媒質に対する吸収補正" 放射線医学物理. 15(発表予定). (1995)

Shigeto Suzuki：“使用 X 射线 CT 数据对 SPECT 不均匀介质进行吸收校正”放射物理学 15（待发表）。

Suzuki Shigehito: "Nonuniform attenuation correction in SPECT using XCT data (to be published)" Japanese Journal of Medical Physics. vol.15. (1995)

铃木重人：“使用 XCT 数据进行 SPECT 中的非均匀衰减校正（待发表）”日本医学物理杂志。