John A. Sexton1,2, John C. Gore1,3, James Chris Gatenby1,3
1Vanderbilt University Institute of Imaging Science, Nashville, TN, USA; 2Biomedical Engineering, Vanderbilt University, Nashville, TN, USA; 3Radiology and Radiological Sciences, Vanderbilt University, Nashville, TN, USA
At high field, magnetic susceptibility effects such as distortion and signal dropout become severe, and the usefulness of single-shot EPI for fMRI becomes limited. Here we consider two alternatives to EPI for fMRI at 7T: 3D Fast Field Echo (FFE) and 3D PRESTO (Principles of Echo Shifting with a Train of Observations). We observe higher t-values and more activated voxels in EPI compared with 3DFFE in high-resolution, limited field-of-view studies (1mm3, 1.2mm3, and 1.75mm3), while PRESTO demonstrates higher t-values and more activated voxels than EPI at lower resolution, large field-of-view studies (3mm3).
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