Fox P T, Mintun M A, Raichle M E, Miezin F M, Allman J M, Van Essen D C
Nature. 1986;323(6091):806-9. doi: 10.1038/323806a0.
Positron-emission tomography (PET) can localize functions of the human brain by imaging regional cerebral blood flow (CBF) during voluntary behaviour. Functional brain mapping with PET, however, has been hindered by PET's poor spatial resolution (typically greater than 1 cm). We have developed an image-analysis strategy that can map functional zones not resolved by conventional PET images. Brain areas selectively activated by a behavioural task can be isolated by subtracting a paired control-state image from the task-state image, thereby removing areas not recruited by the task. When imaged in isolation the centre of an activated area can be located very precisely. This allows subtle shifts in response locale due to changes in task to be detected readily despite poor spatial resolution. As an initial application of this strategy we mapped the retinal projection topography of human primary visual cortex. Functional zones separated by less than 3 mm (centre-to-centre) were differentiated using PET CBF images with a spatial resolution of 18 mm. This technique is not limited to a particular brain area or type of behaviour but does require that the increase in CBF produced by the task be both intense and focal.
正电子发射断层扫描（PET）可通过对自愿行为期间的局部脑血流量（CBF）进行成像来定位人类大脑的功能。然而，PET较差的空间分辨率（通常大于1厘米）阻碍了利用PET进行功能性脑图谱绘制。我们开发了一种图像分析策略，该策略能够绘制常规PET图像无法分辨的功能区。通过从任务状态图像中减去配对的对照状态图像，可以分离出由行为任务选择性激活的脑区，从而去除未被该任务激活的区域。单独成像时，激活区域的中心可以非常精确地定位。这使得尽管空间分辨率较差，但由于任务变化导致的反应位置的细微变化仍能很容易地被检测到。作为该策略的初步应用，我们绘制了人类初级视觉皮层的视网膜投射地形图。使用空间分辨率为18毫米的PET CBF图像，区分了中心距小于3毫米的功能区。该技术不限于特定的脑区或行为类型，但确实要求任务引起的CBF增加既强烈又集中。
