Figure 5.

Detection of the hemodynamic response to a motor stimulus using HP ¹²⁹Xe perfusion mapping corroborated by blood oxygenation level-dependent (BOLD) functional brain MRI (fMRI). (a) Experimental design used for hemodynamic response detection. Two separate perfusion maps were acquired during the control (calm rest) and motor stimulation (left fist clenching) stages. (b) Hemodynamic response map created by subtracting the control perfusion map from the stimulated perfusion map and overlaid on top of the high-resolution proton scan. Activation of the right posterior precentral gyrus (i.e., the motor cortex) was observed. (c) BOLD fMRI experimental design for validation of the HP ¹²⁹Xe technique. (d) BOLD fMRI 3D activation maps. Activation was observed from the motor cortex (green arrow); this result correlated with the HP ¹²⁹Xe hemodynamic response map.