Biomedical Engineering Laboratory, The Graduate School of Natural Science and Technology, Okayama University, Okayama, Japan.
J Magn Reson Imaging. 2011 Feb;33(2):441-7. doi: 10.1002/jmri.22404.
To develop and validate the functionality of a novel wide-view visual presentation system with a horizontal and vertical eccentricity angle of 60° for retinotopic mapping by functional MRI (fMRI).
The wide-view presentation system consisted of a 52-mm diameter optical fiber, an entrance apparatus and a presentation apparatus. The terminal edge of the optical fiber at the entrance is flat, while the terminal edge on the presentation apparatus is a sphere of 60 mm in diameter. The subjects wore contact lenses with +20, +22, or +25 magnification to focus on the stimulus, and the visual field eccentricity angle could reach 60°. The signal to noise ratio valuation experiment was performed to evaluate the clarity and quality of the MRI picture image. Checkerboard and random dot stimuli were used to prove that this system could be applied to retinotopic mapping by fMRI.
The results of the experiment demonstrated that the system is safe in the MRI environment with minimal distortion and can be used for visual retinotopic mapping studies. Wide-field mapping areas (V6, MST) were found in the human visual cortex. Compared with previous studies, the V1 and MT+ surface area approaches but does not fully cover the anatomical area. Nonetheless, the area achieved using the new system is larger than those achievable in previous fMRI studies.
We developed a versatile, low-cost system for presenting wide-view visual stimuli in the MRI environment. The fMRI retinotopic mapping results proved the viability of this system.
开发和验证一种新型的宽视野视觉呈现系统的功能，该系统具有水平和垂直偏心角 60°，可用于功能磁共振成像（fMRI）的视网膜映射。
宽视野呈现系统由 52mm 直径的光纤、入口装置和呈现装置组成。光纤入口处的末端边缘是平的，而呈现装置上的末端边缘是直径为 60mm 的球体。受试者佩戴+20、+22 或+25 度放大倍率的接触镜聚焦于刺激物，视野偏心角可达 60°。进行信噪比评估实验以评估 MRI 图像的清晰度和质量。使用棋盘格和随机点刺激来证明该系统可应用于 fMRI 的视网膜映射。
实验结果表明，该系统在 MRI 环境中安全，失真最小，可以用于视觉视网膜映射研究。在人类视觉皮层中发现了宽场映射区域（V6、MST）。与之前的研究相比，V1 和 MT+的表面积接近但不完全覆盖解剖区域。然而，使用新系统实现的区域大于以前 fMRI 研究中实现的区域。
我们开发了一种在 MRI 环境中呈现宽视野视觉刺激的多功能、低成本系统。fMRI 视网膜映射结果证明了该系统的可行性。
