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首页> 外文期刊>International journal of imaging systems and technology >Variations in BOLD Response Latency Estimated from Event-Related fMRI at 3T: Comparisons Between Gradient-Echo and Spin-Echo
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Variations in BOLD Response Latency Estimated from Event-Related fMRI at 3T: Comparisons Between Gradient-Echo and Spin-Echo

机译:事件相关的功能磁共振成像在3T估计的大胆反应潜伏期的变化:梯度回波和自旋回波之间的比较。

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摘要

Functional magnetic resonance imaging (fMRI) commonly uses gradient-recalled echo (GRE) signals to detect regional hemodynamic variations originating from neural activities. While the spatial localization of activation shows promising applications, indexing temporal response remains a poor mechanism for detecting the timing of neural activity. Particularly, the hemodynamic response may fail to resolve sub-second temporal differences between brain regions because of its signal origin or noise in data, or both. This study aimed at evaluating the performance of latency estimation using different fMRI techniques, with two event-related experiments at 3T. Experiment I evaluated latency variations within the visual cortex and their relationship with contrast-to-noise ratios (CNRs) for GRE, spin echo (SE), and diffusion-weighted SE (DWSE). Experiment Ⅱ used delayed visual stimuli between two hemifields (delay time = 0, 250, and 500 ms, respectively) to assess the temporal resolving power of three protocols: GRE_(TR1000), GRE_(TR500), and SE_(TR1000) The results of experiment Ⅰ showed the earliest latency with DWSE, followed by SE, and then GRE. Latency variations decreased as CNR increased. However, similar variations were found between GRE and SE, when the latter had lower CNR. In experiment Ⅱ, measured stimulus delays from all conditions were significantly correlated with preset stimulus delays. Inter-subject variation in the measured delay was found to be greatest with GRE_(TR1000). Followed by GRE_(TR500), and the least with SE_(TR1000)- Conclusively, blood oxygenation level-dependent responses obtained from GRE exhibit greater CNR but no compromised latency variations in the visual cortex. SE is potentially capable of improving the performance of latency estimation, especially for group analysis.
机译:功能磁共振成像(fMRI)通常使用梯度回波(GRE)信号来检测源自神经活动的局部血液动力学变化。虽然激活的空间定位显示了有前途的应用,但索引时间响应仍然是检测神经活动时间的不良机制。特别是,由于其信号起源或数据中的噪声或两者兼有,血液动力学响应可能无法解决大脑区域之间的亚秒级时间差异。这项研究旨在评估使用不同功能磁共振成像技术的潜伏期估计的性能,并在3T进行了两个事件相关的实验。实验I评估了视觉皮层内的潜伏期变化及其与GRE,自旋回波(SE)和扩散加权SE(DWSE)的对比噪声比(CNR)的关系。实验Ⅱ使用两个半场之间的延迟视觉刺激(分别为延迟时间= 0、250和500 ms)评估三种协议的时间分辨能力:GRE_(TR1000),GRE_(TR500)和SE_(TR1000)结果实验Ⅰ的结果显示DWSE的延迟最早,其次是SE,然后是GRE。延迟变化随着CNR的增加而减小。但是,当GRE和SE的CNR较低时,在GRE和SE之间也发现了类似的变化。在实验Ⅱ中,在所有条件下测得的刺激延迟与预设的刺激延迟显着相关。发现使用GRE_(TR1000),受试者之间的测量延迟差异最大。紧随其后的是GRE_(TR500),最少的是SE_(TR1000)。最终,从GRE获得的血液氧合水平依赖性反应表现出更大的CNR,但在视觉皮层中没有潜伏的延迟变化。 SE潜在地能够改善等待时间估计的性能,尤其是对于组分析而言。

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  • 作者单位

    Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan,Department of Radiology, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan;

    Graduate Institute of Biomedical Engineering, National Central University, Taoyuan, Taiwan;

    Department of Medical Physics, Koo Foundation Sun Yat-Sen Cancer Center, Taipei City, Taiwan;

    Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada;

    Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan,Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Taoyuan, Taiwan;

    Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan,Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Taoyuan, Taiwan;

    Department of Radiology, Chiayi Chang Gung Memorial Hospital, Chiayi, Taiwan;

    Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan,Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Taoyuan, Taiwan,Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan;

  • 收录信息 美国《科学引文索引》(SCI);美国《工程索引》(EI);
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    functional MRI; blood oxygenation level-dependent; gradient-recalled echo; spin echo; latency;

    机译:功能性MRI;血液氧合水平依赖性;梯度回波自旋回波潜伏;

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