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首页> 外文期刊>American Journal of Neuroradiology >False Cerebral Activation on BOLD Functional MR Images: Study of Low-amplitude Motion Weakly Correlated to Stimulus
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False Cerebral Activation on BOLD Functional MR Images: Study of Low-amplitude Motion Weakly Correlated to Stimulus

机译：大胆功能性MR图像上的虚假脑激活：与刺激微弱相关的低振幅运动的研究

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摘要

BACKGROUND AND PURPOSE: Movements of the participant during blood oxygen level–dependent (BOLD) functional MR imaging cerebral activation studies are known to produce occasionally regions of false activation, especially when these movements are relatively large (>3 mm) and highly correlated with the stimulus. We investigated whether minimal (<1 mm), weakly correlated movements in a controlled functional MR imaging model could produce false activation artifacts that could potentially mimic regions of true activation in size, location, and statistical significance. METHODS: A life-size brain phantom was constructed by embedding vials of a dilute carboxylic acid solution within a gadolinium-doped gelatin mold. Imaging was performed at 1.5 T using a 2D spiral sequence (3000/5 [TR/TE]; flip angle, 88°; matrix, 64 x 64; field of view, 24 cm; section thickness, 5 mm). Controlled, in-plane, submillimeter movements of the phantom were generated using a pneumatic system and were made to correlate with a hypothetical "boxcar" stimulus over the range 0.31 < r < 0.96. Regions of false activation were sought using standard statistical methods (SPM96) that excluded phantom edges and accounted for spatial extent (regions tested at P < .05, corrected for multiple comparisons). A similar experiment was performed on a resting volunteer. RESULTS: The pneumatic system provided motion control with average in-plane displacements and rotations of 0.74 mm and 0.47°, respectively, in the 18 data sets analyzed. No areas of false activation in the phantom were identified for poorly correlated motions (r 0.67, areas of false activation were seen in every experiment. For a statistical threshold of P = .001, the median number of falsely activated regions was 3.5, with a mean size of 71.7 voxels (approximately 5 cc). Areas of possibly false activation of average size 72.5 voxels resulting from passive motion of the resting human participant were observed in two of four experiments. CONCLUSION: Participant movements of 1 mm or less that are only modestly correlated with a blocked stimulus paradigm can produce appreciable false activation artifacts on BOLD functional MR imaging studies, even when strict image realignment methods are used to prevent them.
机译：背景与目的：参与者在 血氧水平依赖性（BOLD）功能性MR成像 大脑激活研究期间的运动有时会产生 区域错误激活，尤其是当这些运动 相对较大（> 3 mm）并且与 刺激高度相关时。我们调查了在受控功能性MR成像模型中 的最小（<1 mm），弱 相关运动是否可能产生错误的激活伪像，这些伪像可能潜在地 模仿在大小，位置和统计学意义上真正激活的区域。 方法：通过嵌入稀释的 小瓶来构建真人大小的脑模型。 s掺杂的 明胶模具中的羧酸溶液。使用2D螺旋 序列（3000/5 [TR / TE]；翻转角为88°；矩阵为64 x 64；在1.5 T下进行成像，24厘米；截面厚度为5毫米）。使用气动系统产生幻像的受控的 平面内亚毫米运动，并使其与假设的 “棚车”刺激相关在0.31 （SPM96）来寻找错误激活的区域 （SPM96），该方法排除了幻影边缘，并说明了空间 范围（以P <测试的区域。 05，已针对多个 比较进行了更正）。结果对静止的 志愿者进行了类似的实验。 结果：气动系统提供了平均 平面位移和旋转0.74 mm的运动控制。在分析的18个数据集中分别为0.47°， 。没有发现幻影中虚假 激活的区域的相关性较弱的 运动（在每个实验中均看到r 0.67， 虚假激活的区域。 统计阈值P = .001，错误地激活了 的区域的中位数为3.5，平均大小为71.7体素（大约 5 cc）。在四个实验中的两个实验中，观察到了由静息的人类参与者 的被动运动导致的平均大小72.5 体素可能被错误激活的区域。 >结论：仅 与受阻刺激范例适度相关的1 mm或更小的参与者运动会在BOLD功能性MR 明显的错误激活伪像>成像研究，即使使用严格的图像重新对准方法 来防止它们。

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  • 来源
    《American Journal of Neuroradiology》 |2000年第8期|1388-1396|共9页
  • 作者

    Aaron S. Field; Yi-Fen Yen; Jonathan H. Burdette; Allen D. Elster;

  • 作者单位

    From the Division of Radiologic Sciences, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1022.;

    From the Division of Radiologic Sciences, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1022.;

    From the Division of Radiologic Sciences, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1022.;

    From the Division of Radiologic Sciences, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1022.;

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