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Temporal filtering effects in dynamic parallel MRI
Author(s) -
Blaimer Martin,
Ponce Irene P.,
Breuer Felix A.,
Jakob Peter M.,
Griswold Mark A.,
Kellman Peter
Publication year - 2011
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.22795
Subject(s) - aliasing , signal (programming language) , computer science , temporal resolution , sensitivity (control systems) , raw data , filter (signal processing) , calibration , artificial intelligence , electromagnetic coil , image (mathematics) , computer vision , mathematics , electronic engineering , physics , optics , statistics , quantum mechanics , programming language , engineering
Autocalibrated parallel MRI methods such as TSENSE or k ‐ t SENSE have been presented for dynamic imaging studies as they are able to provide images with high temporal resolution. One key element of these techniques is the temporal averaging of the undersampled raw data to obtain an unaliased image. This image represents the temporal average (also known as direct current, DC) and is used to derive the reconstruction parameters. In this work, we show that aliasing artifacts can be introduced in the DC signal obtained from the undersampled raw data. These artifacts lead to undesired temporal filtering effects when the DC signal is used for coil sensitivity calibration or when the DC signal is subtracted from the raw data. It is demonstrated that the temporal filtering effects can be reduced significantly by filtering the DC signal. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.