Background

A common limitation of typical projection systems used for visual fMRI is the limited field of view that can be presented to the observer within the scanner. A wide field of view over which stimuli can be presented is critical when investigating peripheral visual function, in particular visual disorders or diseases that lead to the loss of peripheral vision.

New method

We present a relatively low-cost Galilean telescopic device that can be used in most MRI scanners to double the effective visual field being presented. The system described is non-ferromagnetic, and compatible with most standard methods of visual presentation in MRI environments. The increase in area of visual cortex activation was quantified by comparing the extent of visual activity evoked by observing flickering checkerboards with and without the telescope in place.

Results

In all three observers that reported image fusion from the telescope, the extent of cortical activation was greater with the telescope, while in the fourth observer there was no difference between the two methods due to a lack of fusion.

Conclusion

The telescope is a low cost, easy to implement solution in situations where changes to the existing equipment or setup are not feasible.

中文翻译：

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用于增强功能性MRI刺激视野覆盖的低成本望远镜

背景

用于视觉功能磁共振成像的典型投影系统的常见局限性是可以在扫描仪内呈现给观察者的有限视野。在研究周围视觉功能时，尤其是导致周围视力丧失的视觉障碍或疾病时，可在其上施加刺激的广阔视野至关重要。

新方法

我们提出了一种成本相对较低的伽利略望远镜设备，该设备可以在大多数MRI扫描仪中使用，以使呈现的有效视野加倍。所描述的系统是非铁磁性的，并且与MRI环境中的大多数标准视觉呈现方法兼容。通过比较在有和没有望远镜的情况下观察闪烁的棋盘引起的视觉活动程度来量化视觉皮层激活区域的增加。

结果

在从望远镜报告图像融合的所有三位观察者中，使用望远镜观察皮质激活的程度更大，而在第四位观察者中，由于缺乏融合，两种方法之间没有差异。

结论

在对现有设备或装置进行更改不可行的情况下，该望远镜是一种低成本，易于实施的解决方案。