Using high spatial resolution to improve BOLD fMRI detection at 3T

Iranpour, Juliana; Morrot, Gil; Claise, Béatrice; Jean, Betty; Bonny, Jean-Marie

Using high spatial resolution to improve BOLD fMRI detection at 3T

2015

Iranpour, Juliana | Morrot, Gil | Claise, Béatrice | Jean, Betty | Bonny, Jean-Marie

For different functional magnetic resonance imaging experiments using blood oxygenationlevel-dependent (BOLD) contrast, the acquisition of T2*-weighted scans at a high spatialresolution may be advantageous in terms of time-course signal-to-noise ratio and of BOLDsensitivity when the regions are prone to susceptibility artifacts. In this study, we explorethis solution by examining how spatial resolution influences activations elicited when appetizingfood pictures are viewed. Twenty subjects were imaged at 3 T with two different voxelvolumes, 3.4 μl and 27 μl. Despite the diminution of brain coverage, we found that high-resolutionacquisition led to a better detection of activations. Though known to suffer to differentdegrees from susceptibility artifacts, the activations detected by high spatial resolution werenotably consistent with those reported in published activation likelihood estimation metaanalyses,corresponding to taste-responsive regions. Furthermore, these regions werefound activated bilaterally, in contrast with previous findings. Both the reduction of partialvolume effect, which improves BOLD contrast, and the mitigation of susceptibility artifact,which boosts the signal to noise ratio in certain regions, explained the better detectionnoted with high resolution. The present study provides further evidences that high spatialresolution is a valuable solution for human BOLD fMRI, especially for studying food-relatedstimuli.

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