| 贾传海,卢光明,张志强,汪泽,黄伟,马飞,尹婕,黄振平,邵庆.人类弱视视觉皮层fMRI反应与对比敏感度的相关性[J].中国医学影像技术,2009,25(11):1975~1979 |
| 人类弱视视觉皮层fMRI反应与对比敏感度的相关性 |
| Correlation between the visual cortical fMRI response and the contrast sensitivity in human amblyopia |
| 投稿时间：2009-04-15 修订日期：2009-05-10 |
| DOI： |
| 中文关键词: 弱视 磁共振成像 对比敏感度 |
| 英文关键词:Amblyopia Magnetic resonance imaging Contrast sensitivity |
| 基金项目:国家自然科学基金面上项目(30670600)。 |
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| 中文摘要: |
| 目的 探讨人类弱视视觉皮层fMRI反应与心理物理学指标对比敏感度之间的相关性。方法 以1.5T MR采集9名正常人、10例单眼屈光参差性弱视患者和10例单眼斜视性弱视患者对视网膜脑图刺激和6 cpd空间频率、50%对比度的黑白光点刺激的视觉皮层功能数据,划分出每个受试者的视觉皮层区,计算各个区的平均反应T值,与正常对照组主导眼对比,观察两种类型弱视视觉皮层损害情况。检测所有受试者健眼和弱视眼对比敏感度值。对弱视眼有损害的皮层功能区平均反应T值及弱视眼对比敏感度值标准化后进行线性回归分析。结果 屈光参差性弱视在V1、V2、V3、Vp及V7区,斜视性弱视在V1、V2、Vp区有功能损害(P<0.05),在这些损害的皮层功能区,两弱视组标准化反应T值及标准化对比敏感度值之间无统计学意义。结论 弱视皮层损害区的fMRI反应与对比敏感度之间无相关,原因可能为对比敏感度减低是由于具有感知低对比度属性的神经元阈值在高空间频率下升高,而fMRI不能有效检测出此种变化,也可能与fMRI本身技术局限性及刺激类型有关。 |
| 英文摘要: |
| Objective To assess the correlation between the visual cortical fMRI response and the contrast sensitivity in human amblyopia. Methods Ten anisometropic amblyopes, 10 strabismic amblyopes and 9 normal subjects underwent fMRI with retinotopic mapping and luminous spots stimuli (spatial frequency: 6 cpd, contrast: 0.5). 1.5T MR was used to obtain functional images of visual cortex. Then the visual functional areas and the average T value were figured out. Comparing with the normal group, the functional deficits in anisometropic and strabismic amblyopia were observed. The contrast sensitivity was tested. The contrast sensitivity and the average T value of the impaired visual cortical areas were analyzed regressively in the two amblyopia groups, respectively. Results Amblyopic eyes showed that V1, V2, V3, VP and V7 areas in anisometropic amblyopia group, V1, V2 and Vp areas in strabismic amblyopia group had functional deficits compared with the dominant eyes of the normal group (P<0.05). There was no statistical difference between the normalized average T value in the impaired visual cortical areas and the normalized contrast sensitivity value. Conclusion No correlation is found between the visual cortical fMRI response and the contrast sensitivity in human amblyopia. The causes may include that the contrast sensitivity deficit is due to the thresholds elevation of the neurons with low contrast at the higher spatial frequency, but fMRI cant detect this change effectively, as well as the technical limitations of fMRI itself and the type of stimulus. |
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