Lu Hanbing, Soltysik David A, Ward B Douglas, Hyde James S
Department of Biophysics, Medical College of Wisconsin, Milwaukee, 53226, USA.
Neuroimage. 2005 Jun;26(2):432-40. doi: 10.1016/j.neuroimage.2005.02.016. Epub 2005 Apr 1.
Cerebral blood volume functional magnetic resonance imaging (CBV-fMRI) experiments employing iron oxide contrast agent were conducted in rat whisker barrel cortex at 3 Tesla. Stimuli of constant frequency (12 Hz) but variable duration and intensity were delivered separately using a homemade whisker stimulator. The temporal behavior of CBV-fMRI signals was investigated using a linearity analysis method. Both superposition and scaling tests show that CBV-fMRI responses are generally consistent with a linear time-invariant (LTI) model. In particular, the response to a stimulus of higher intensity can be linearly scaled from that of lower intensity. However, significant deviations exist when the stimulus duration is manipulated, particularly in the trailing edge of the CBV-fMRI response curves.
在3特斯拉磁场下，对大鼠的触须桶状皮层进行了使用氧化铁造影剂的脑血容量功能磁共振成像（CBV-fMRI）实验。使用自制的触须刺激器分别施加频率恒定（12赫兹）但持续时间和强度可变的刺激。使用线性分析方法研究了CBV-fMRI信号的时间行为。叠加测试和缩放测试均表明，CBV-fMRI反应通常与线性时不变（LTI）模型一致。特别是，对较高强度刺激的反应可以从较低强度刺激的反应线性缩放得到。然而，当操纵刺激持续时间时，会存在显著偏差，尤其是在CBV-fMRI反应曲线的后沿部分。
