Accelerated 4D quantitative single point EPR imaging using model‐based reconstruction. Issue 4 (6th May 2014)

• Record Type: Journal Article
• Authors: Jang, Hyungseok; Matsumoto, Shingo; Devasahayam, Nallathamby; Subramanian, Sankaran; Zhuo, Jiachen; Krishna, Murali C.; McMillan, Alan B.
• Is Part Of: Magnetic resonance in medicine. Volume 73:Issue 4(2015:Apr.)
• Page Start: 1692
• Page End: 1701
• Publication Date: 2014-05-06
• Subjects: Electron paramagnetic resonance imaging -- quantitative imaging -- single‐point imaging -- model‐based reconstruction -- k‐space extrapolation; Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.25282
• Languages: English
• ISSNs: 0740-3194

Abstract

Abstract : Purpose: Electron paramagnetic resonance imaging has surfaced as a promising noninvasive imaging modality that is capable of imaging tissue oxygenation. Due to extremely short spin‐spin relaxation times, electron paramagnetic resonance imaging benefits from single‐point imaging and inherently suffers from limited spatial and temporal resolution, preventing localization of small hypoxic tissues and differentiation of hypoxia dynamics, making accelerated imaging a crucial issue. Methods: In this study, methods for accelerated single‐point imaging were developed by combining a bilateral k‐space extrapolation technique with model‐based reconstruction that benefits from dense sampling in the parameter domain (measurement of the T2 * decay of a free induction delay). In bilateral kspace extrapolation, more k‐space samples are obtained in a sparsely sampled region by bilaterally extrapolating data from temporally neighboring k‐spaces. To improve the accuracy of T2 * estimation, a principal component analysis‐based method was implemented. Results: In a computer simulation and a phantom experiment, the proposed methods showed its capability for reliable T2 * estimation with high acceleration (8‐fold, 15‐fold, and 30‐fold accelerations for 61×61×61, 95×95×95, and 127×127×127 matrix, respectively). Conclusion: By applying bilateral k‐space extrapolation and model‐based reconstruction, improved scan times with higher spatial resolution can be achieved in the current single‐point electron paramagnetic resonance imaging modality.Magn Reson Med 73:1692–1701, 2015. © 2014 Wiley Periodicals, Inc.