Real-Time Oblique Echo-Planar Imaging: Ghosting Artifact Reduction in Arbitrary Scan Orientations
Nielsen J, Kim Y, Nayak K
University of Southern California
In EPI, ghosting artifacts due to gradient timing errors can be corrected if the scan plane is on axis. Oblique scan planes pose additional considerations and conventional methods solve them by measuring gradient delays. We present a new ghosting reduction method of not requiring gradient delay information. It adopts a double-alternating EPI readout, where traversal in k-space alternates every phase-encode and every frame. Sensitivity encoding (SENSE) is used to recover full FOV images. Sensitivity maps are estimated on-the-fly similar to TSENSE, and they are ghost free. Cardiac results indicate that this method makes real-time EPI robust against scan orientation changes.