PET图像中球形病灶的部分容积效应及其影响因素

发布时间：2018-02-23 11:59

本文关键词： PET 部分容积效应影响因素模拟实验　出处：《原子能科学技术》2014年06期 　论文类型：期刊论文

【摘要】：依据形成部分容积效应的理论,由计算机模拟球形病灶(直径2~30mm)位于各种背景(背景与病灶强度之比为0~0.7)中时,PET设备(分辨率3~15mm)的成像实验。计算模拟图像中病灶的像素最大值、平均值及半高宽,由此探讨球形病灶PET成像的部分容积效应与相关影响因素间的关系,为进一步建立部分容积效应校正方法提供依据。结果表明:对于任一分辨率和背景强度,图像上病灶信号强度的最大值及平均值随病灶直径的增大而呈S形增加;对于任一病灶直径和背景强度,病灶强度的最大值及平均值随分辨率的增大而呈倒S形减小;对于任一病灶直径和分辨率,病灶强度的最大值及平均值随背景强度线性增加,以背景为基点时,高出背景的病灶强度(最大值、平均值)与相应病灶真值之比不随背景强度变化;对任一病灶直径和分辨率,病灶半高宽不随背景强度变化;当病灶直径大于分辨率时,病灶半高宽与其真实直径很接近,但随分辨率变差,其接近程度也变差;当病灶直径小于分辨率时,病灶半高宽基本不再随直径变小而变小,而是基本等于空间分辨率,并保持不变。
[Abstract]:According to the theory of forming partial volume effect, The imaging experiments of PET equipment (315mm resolution) were simulated by computer in a variety of backgrounds (the ratio of background to focus intensity was 0 ~ 0.7 mm). The maximum pixel value, mean value and half maximum width of the lesion in the simulated image were calculated. The relationship between partial volume effect and related factors in spherical PET imaging is discussed, which provides a basis for further establishment of partial volume effect correction method. The results show that: for any resolution and background intensity, The maximum and average signal intensity of the lesion increased with the increase of the diameter of the lesion, and the maximum and the average value of the intensity of the lesion decreased with the increase of the resolution for any lesion diameter and background intensity. For any lesion diameter and resolution, the maximum and average intensity of the lesion increases linearly with the background intensity. When the background is the base point, the intensity of the lesion is higher than that of the background. The ratio of mean value to the true value of the corresponding lesion does not vary with the background intensity; for any lesion diameter and resolution, the width of the lesion half height does not change with the background intensity; when the diameter of the lesion is larger than the resolution, the width of the lesion is close to its true diameter. When the diameter of the lesion is smaller than the resolution, the width of the lesion is no longer reduced with the diameter becoming smaller, but is basically equal to the spatial resolution and remains unchanged.
【作者单位】：中国人民解放军总医院核医学科;中国医学科学院肿瘤医院核医学科;
【基金】：国家自然科学基金资助项目(60572003) 科技部国际科技合作项目资助(2009DFA32960)
【分类号】：R310

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