Functional MRI of the human amygdala?

In view of an increasing number of publications that deal with functional m apping of the human amygdala using blood oxygenation-level-dependent (BOLD) magnetic resonance imaging, we reevaluated the underlying image quality of T2*-weighted echoplanar imaging (EPI) and fast low angle shot (FLASH) sequ ences at 2.0-T with regard to susceptibility-induced signal losses and geom etric distortions. Apart from the timing of the gradient echoes, the degree of susceptibility influences is controlled by the image voxel size. Wherea s published amygdala studies report voxel sizes ranging from 22 to 125 mul, the present results suggest that reliable imaging of the amygdala with BOL D sensitivity requires voxel sizes of 4 to 8 mul or less. Preferentially, a cquisitions should be performed with a coronal section orientation. Althoug h high-resolution BOLD MRI is at the expense of temporal resolution and vol ume coverage, it seems to provide the only solution to this physical proble m. (C) 2001 Academic Press.