A g‐factor metric for k‐t‐GRAPPA‐ and PEAK‐GRAPPA‐based parallel imaging. Issue 1 (18th July 2014)

• Record Type: Journal Article
• Authors: Ramb, Rebecca; Binter, Christian; Schultz, Gerrit; Assländer, Jakob; Breuer, Felix; Zaitsev, Maxim; Kozerke, Sebastian; Jung, Bernd
• Is Part Of: Magnetic resonance in medicine. Volume 74:Issue 1(2015:Jul.)
• Page Start: 125
• Page End: 135
• Publication Date: 2014-07-18
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.25386
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mrm25386-sec-0001" sec-type="section"> <title>Purpose</title> <p>The aim of this work is to derive a theoretical framework for quantitative noise and temporal fidelity analysis of time‐resolved k‐space‐based parallel imaging methods.</p> </sec> <sec id="mrm25386-sec-0002" sec-type="section"> <title>Theory</title> <p>An analytical formalism of noise distribution is derived extending the existing g‐factor formulation for nontime‐resolved generalized autocalibrating partially parallel acquisition (GRAPPA) to time‐resolved k‐space‐based methods. The noise analysis considers temporal noise correlations and is further accompanied by a temporal filtering analysis.</p> </sec> <sec id="mrm25386-sec-0003" sec-type="section"> <title>Methods</title> <p>All methods are derived and presented for k‐t‐GRAPPA and PEAK‐GRAPPA. A sliding window reconstruction and nontime‐resolved GRAPPA are taken as a reference. Statistical validation is based on series of pseudoreplica images. The analysis is demonstrated on a short‐axis cardiac CINE dataset.</p> </sec> <sec id="mrm25386-sec-0004" sec-type="section"> <title>Results</title> <p>The superior signal‐to‐noise performance of time‐resolved over nontime‐resolved parallel imaging methods at the expense of temporal frequency filtering is analytically confirmed. Further, different temporal frequency filter characteristics of k‐t‐GRAPPA, PEAK‐GRAPPA, and sliding window are revealed.</p> </sec> <sec id="mrm25386-sec-0005" sec-type="section"> <title>Conclusion</title> <p>The proposed analysis of noise behavior and temporal fidelity establishes a theoretical basis for a quantitative evaluation of time‐resolved reconstruction methods. Therefore, the presented theory allows for comparison between time‐resolved parallel imaging methods and also nontime‐resolved methods. Magn Reson Med 74:125–135, 2015. © 2014 Wiley Periodicals, Inc.</p> </sec> </abstract>