Investigating the Impact of Spatially Selective Signal Suppression on BOLD fMRI Reliability

Motivation: Reduced field-of-view (rFOV) imaging can improve spatio-temporal resolution in functional MRI (fMRI), but its impact on activation detection has not (to our knowledge) been examined. Goal(s): To design a short (6ms) outer-volume-suppression (OVS) RF pulse for rFOV fMRI, and investigate its impact on the sensitivity and reliability of BOLD fMRI activation. Approach: We obtained accelerated (R=7.5) BOLD data during four repetitions of a block finger-tapping task, with and without OVS. We assessed test-retest reliability of the activation maps using receiver-operating-characteristic (ROC) analysis. Results: The 6 ms OVS pulse somewhat lowers sensitivity to motor cortex BOLD activation, but somewhat improves test-retest reliability. Impact: Outer-volume suppressed fMRI can produce reliable activation maps, and may be a promising candidate for high-resolution (e.g., layer-specific) fMRI.