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Abstract #1382

Hadamard Slice Encoding for Reduced-FOV Single-Shot Diffusion-Weighted EPI

Emine Ulku Saritas1, Ajit Shankaranarayanan2, Dwight George Nishimura1

1Department of Electrical Engineering, Stanford University, Stanford, CA, USA; 2Global Applied Science Laboratory, GE Healthcare, Menlo Park, CA, USA

A reduced-FOV single-shot EPI method that uses a 90o 2D echo-planar RF excitation has recently been proposed to achieve high-resolution DWI. This method is compatible with contiguous multi-slice imaging without the need for slice skip. However, there is a limit on the number of slices that can be imaged in a simultaneously, determined by the number of slices that can fit between the two adjacent sidelobes of the periodic 2D excitation profile. In this work, we present two different Hadamard slice encoding schemes to double the number of slices for the reduced-FOV method. Specifically, the refocusing 180o RF pulse used to achieve Hadamard slice encoding can be applied either on the two adjacent sidelobes, or on the main lobe of the 2D excitation profile.