Head movement in normal subjects during simulated PET brain imaging with and without head restraint.
Head movement in normal subjects during simulated PET brain imaging with and without head restraint.
复制标题
模拟 PET 脑成像期间正常受试者在有或没有头枕的情况下的头部运动。
DOI：
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发表时间：
1994
影响因子：
9.3
通讯作者：
Tom A. Zeffiro
中科院分区：
文献类型：
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作者：
Michael V. Green;Jurgen Seidel;Stacey D. Stein;Thomas E. Tedder;Kenneth M. Kempner;Caroline Kertzman;Tom A. Zeffiro
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脑成像过程中的头部运动被认为是PET和大多数其他形式的医学脑成像中图像退化的一个来源。然而，关于这些研究中实际发生的头部运动的种类和数量的定量信息很少。我们试图通过测量正常志愿者的头部运动来获得这一信息。
方法
对13名仰卧位受试者分别进行40min的头位数据采集。然后，这些数据被用来驱动一个数学模拟的头部通过完全相同的一组动作。在每个位置计算嵌入该头部的点源的位置，并将这些数据总结为在三个坐标方向上的半高宽移动。
结果
在任何一种类型的研究中，头部活动量随着采样间隔的长度而增加(无论是否有头箍)，但在有头箍的情况下增加的数量和速度要小得多。相比之下，在连续的短采样间隔期间，头部移动很小，并且不会随着时间的推移而增加。在每个研究类型中都发现了头部运动的空间梯度，并且在不同研究类型之间发现了显著的头部运动的空间差异。
结论
在正常的仰卧位受试者中，头部运动虽然很小，但可能会导致大脑成像研究的有效分辨率在空间和时间上发生变化。使用头部约束可以显著减少这些影响，也可以通过将单个图像的采集划分为一系列短图像(而不是单个长图像)、在空间上对齐这些图像并对结果求和来减少这些影响。
UNLABELLED
Head movement during brain imaging is recognized as a source of image degradation in PET and most other forms of medical brain imaging. However, little quantitative information is available on the kind and amount of head movement that actually occurs during these studies. We sought to obtain this information by measuring head movement in normal volunteers.
METHODS
Head position data were acquired for 40 min in each of 13 supine subjects with and without head restraint. These data were then used to drive a mathematically simulated head through exactly the same set of movements. The positions of point sources embedded in this head were computed at each location and these data summarized as movement at FWHM in each of the three coordinate directions.
RESULTS
Head movement increased with the length of the sampling interval for studies of either type (with or without head restraint), but the amount and rate of increase with restraint was much smaller. In contrast, head movement during consecutive, short sampling intervals was small and did not increase with time. Spatial gradients in head movement were detected within each study type, and significant spatial differences in head movement were found between study types.
CONCLUSIONS
Head movements in normal, supine subjects, though small, can cause the effective resolution of a brain imaging study to appear to vary in space and time. These effects can be reduced significantly with head restraint and may also be reduced by dividing the acquisition of a single image into a sequence of short images (instead of a single long image), aligning these images spatially and summing the result.