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Ghost artifact cancellation using phased array processing
Author(s) -
Kellman Peter,
McVeigh Elliot R.
Publication year - 2001
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1196
Subject(s) - artifact (error) , phased array , computer science , artificial intelligence , telecommunications , antenna (radio)
In this article, a method for phased array combining is formulated which may be used to cancel ghosts caused by a variety of distortion mechanisms, including space variant distortions such as local flow or off‐resonance. This method is based on a constrained optimization, which optimizes SNR subject to the constraint of nulling ghost artifacts at known locations. The resultant technique is similar to the method known as sensitivity encoding (SENSE) used for accelerated imaging; however, in this formulation it is applied to full field‐of‐view (FOV) images. The method is applied to multishot EPI with noninterleaved phase encode acquisition. A number of benefits, as compared to the conventional interleaved approach, are reduced distortion due to off‐resonance, in‐plane flow, and EPI delay misalignment, as well as eliminating the need for echo‐shifting. Experimental results demonstrate the cancellation for both phantom as well as cardiac imaging examples. Magn Reson Med 46:335–343, 2001. Published 2001 Wiley‐Liss, Inc.