Two-step navigatorless correction algorithm for radial k-space MRI acquisitions

A new way to correct magnetic resonance image artifacts resulting from view -dependent phase variations and view-dependent Variations in rigid body obj ect translation is presented by exploiting basic properties of the trajecto ry of radial k-space acquisitions. Simulations, phantom studies, and in viv o experiments are used to demonstrate the feasibility and the utility of th is method. While somewhat analogous to navigator echo correction, in which special gradients are interleaved into the imaging sequence so echoes at th e center of k-space can be acquired prior to or after collection of the ima ge data, the current method does not require additional new gradient struct ures within the pulse sequence or increases in scan time, The new method us es the phase information from all collected radial k-space data points rath er than only the navigator echo, which permits correction of multiple sourc es of view-dependent phase variation in the image data. The resultant effec t is improved image quality in radial MRI acquisitions. Magn Reson Med 45:2 77-288, 2001, (C) 2001 Wiley-Liss, Inc.