Feasibility of Structural and Functional MRI Acquisition with Unpowered Implants in Argus II Retinal Prosthesis Patients: A Case Study
Feasibility of Structural and Functional MRI Acquisition with Unpowered Implants in Argus II Retinal Prosthesis Patients: A Case Study
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DOI：
10.1167/tvst.4.6.6
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发表时间：
2015-11-01
影响因子：
3
通讯作者：
Tjan, Bosco S.
中科院分区：
文献类型：
--
作者：
Cunningham, Samantha I.;Shi, Yonggang;Tjan, Bosco S.
目的：磁共振成像（MRI）可以测量视力丧失和恢复对脑功能和结构的影响。在本病例研究中，我们试图确定在接受Argus II视网膜前膜假体系统的患者中获取解剖和功能MRI数据的可行性。方法：在成功植入Argus II器械后，两名视网膜色素变性（RP）患者在植入物无动力的情况下完成了MRI扫描，以测量初级视觉皮层（V1）对触觉任务的功能反应、全脑形态测量、V1皮层厚度，以及视束和视辐射的扩散特性。Argus II植入物的受试者中的测量值进行了比较，以前从RP患者和有视力的individual.Results：Argus II植入物的存在导致的工件，被定位在患者的植入眼周围，并没有延伸到皮质区域或与视觉系统相关的白色物质束。从两名Argus II受试者获得的V1皮质厚度和离视网膜束的结构数据在视力和RP组的范围内。当与RP和有视力的受试者相比时，Argus II患者在V1中的睡眠诱发的跨模态功能性MRI（fMRI）血氧水平依赖性（BOLD）反应也落在有视力或RP组的范围内，这显然取决于植入后的时间。本研究表明，在存在非活性植入物的情况下，结构和功能MR图像的成功采集和量化是可行的，提供了视力恢复治疗后大脑功能变化的初步信息。
Purpose: Magnetic resonance imaging (MRI) can measure the effects of vision loss and recovery on brain function and structure. In this case study, we sought to determine the feasibility of acquiring anatomical and functional MRI data in recipients of the Argus II epiretinal prosthesis system.Methods: Following successful implantation with the Argus II device, two retinitis pigmentosa (RP) patients completed MRI scans with their implant unpowered to measure primary visual cortex (V1) functional responses to a tactile task, whole-brain morphometry, V1 cortical thickness, and diffusion properties of the optic tract and optic radiation. Measurements in the subjects with the Argus II implant were compared to measurements obtained previously from RP patients and sighted individuals.Results: The presence of the Argus II implant resulted in artifacts that were localized around the patient's implanted eye and did not extend into cortical regions or white matter tracts associated with the visual system. Structural data on V1 cortical thickness and the retinofugal tract obtained from the two Argus II subjects fell within the ranges of sighted and RP groups. When compared to the RP and sighted subjects, Argus II patients' tactile-evoked cross-modal functional MRI (fMRI) blood oxygen leveldependent (BOLD) responses in V1 also fell within the range of either sighted or RP groups, apparently depending on time since implantation.Conclusions: This study demonstrates that successful acquisition and quantification of structural and functional MR images are feasible in the presence of the inactive implant and provides preliminary information on functional changes in the brain that may follow sight restoration treatments.