Research Article

Transfer Function Analysis of Respiratory and Cardiac Pulsations in Human Brain Observed on Dynamic Magnetic Resonance Images

Figure 2

FastICA segmentation results for the dynamic images are displayed in Figure 1, which include the following: four output images with their frames displayed in different colors (a–d), corresponding signal-time curves (e), and corresponding amplitude spectrum (f). The phase, , calculated by using transfer function analysis and the complex-valued spectrum of the green signal-time curve as a reference function are illustrated in (g). The respiratory and cardiac frequency bands are marked by yellow shaded areas. Note that constant phases are observable at the respiratory (black, red, and blue curves) and cardiac pulsations (black and red curves).
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(a)
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(b)
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(c)
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(d)
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(e)
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(f)
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(g)