BOLD technique is used by which MRI sequence?

Blood oxygenation level dependent (BOLD) Imaging Is the standard technique used to generate images in functional MRI (fMRI) studies, and relies on regional differences in cerebral blood flow to delineate regional activity. Blood flow in the brain is highly locally controlled in response to oxygen and carbon dioxide tension of coical tissue. When a specific region of the coex increases its activity in response to a task, the extraction fraction of oxygen from the local capillaries leads to an initial drop in oxygenated haemoglobin (oxyHb) and an increase in local carbon dioxide (CO2) and deoxygenated haemoglobin (deoxyHb). The reason fMRI is able to detect this change is due to a fundamental difference in the paramagnetic propeies of oxyHb and deoxyHb.