Motion correction with PROPELLER MRI: Application to head motion and free-breathing cardiac imaging

A method for motion correction, involving both data collection and reconstr uction, is presented. The PROPELLER MRI method collects data in concentric rectangular strips rotated about the k-space origin. The central region of k-space is sampled for every strip, which (a) allows one to correct spatial inconsistencies in position, rotation, and phase between strips, (b) allow s one to reject data based on a correlation measure indicating through-plan e motion, and (c) further decreases motion artifacts through an averaging e ffect for low spatial frequencies. Results are shown in which PROPELLER MRI is used to correct for bulk motion in head images and respiratory motion i n nongated cardiac images. Magn Reson Med 42:963-969, 1999. (C) 1999 Wiley- Liss, Inc.