DIFFUSION-WEIGHTED INTERLEAVED ECHO-PLANAR IMAGING WITH A PAIR OF ORTHOGONAL NAVIGATOR ECHOES

This work describes a diffusion-weighted (DW) interleaved echo-planar imaging (IEPI) method for use on either conventional whole-body scanne rs or scanners equipped with highspeed gradient and receiver hardware, In combination with cardiac gating and motion correction with a pair of orthogonal navigator echoes, the presented method is time-efficient , compensates for patient motions, and is less sensitive to image dist ortions than single-shot methods. The motion-correction scheme consist s of correction for constant and linear phase terms found from the ort hogonal navigator echoes, The correction for the linear phase term in the phase-encode direction includes gridding the data to the Cartesian grid, The DW IEPI was used to image a phantom rotating about the slic e-select direction, and motion correction was performed to eliminate g host artifacts arising from motion in either the readout- or phase-enc oding directions, DW IEPI with motion correction was performed on a no rmal volunteer and on a patient with a 26-day-old region of ischemia o ver much of the right hemisphere.