Practice question

Functional imaging of cerebral blood flow and oxygen metabolism traditionally relies on coupling between neuronal activity and hemodynamics. Functional magnetic resonance imaging exploits this by detecting changes in deoxyhemoglobin paramagnetism following activation, providing indirect maps of regional flow and oxygen extraction. Increased activity elevates local perfusion, altering signal intensity. Computed tomography images X-ray density for structure, EEG measures electrical potentials with limited spatial specificity, diffusion tensor imaging tracks water diffusion anisotropy for tract anatomy, not dynamic perfusion. Thus fMRI best reflects blood flow and oxygen use functionally.