W. Scott Hoge1, Hong Pan1, Ravi T. Seethamraju2, Keith A. Heberlein3, Emily Stern1
1Radiology, Brigham and Women's Hospital, Boston, MA, United States; 2Siemens Healthcare, Boston, MA, United States; 3Siemens Healthcare USA, Boston, MA, United States
We present a method combining a reduced field of view (rFOV) EPI acquisition sequence with z-shim compensation. Echo planar imaging of the human brain suffers from geometric distortion and signal loss near regions of high magnetic susceptibility, such as near the nasal sinuses. rFOV is effective in reducing in-plane distortion, but requires z-shim compensation to mitigate signal loss from local through-plane gradients. Z-shim compensation combined with rFOV-EPI enables a comprehensive solution to susceptibility artifacts in EPI, and is an important step towards achieving high temporal- and spatial-resolution functional imaging of deep brain structures.