Counterbalancing mismatched magnetization differences in functional arterial spin labeling
Ho Y, Petersen E, Golay X
National Neuroscience Institute
Functional arterial spin labeling (ASL) allows imaging of cerebral blood flow (CBF) changes during neuronal activity, but the large dynamic changes in CBF defy the assumption of steady-state condition. Large fluctuations of estimated CBF values would therefore often result around the transitions between activation and baseline blocks. Functional runs typically have even volumes per block, resulting in regular control-label occurrences. We propose a simple method of counterbalancing the mismatched magnetization differences by acquiring equal numbers of control and labeled scans for each particular phase in the stimulation cycle by using an odd number of acquisitions between stimulation epochs.