Motion‐insensitive rapid configuration relaxometry. Issue 2 (8th September 2016)

• Record Type: Journal Article
• Authors: Nguyen, Damien; Bieri, Oliver
• Is Part Of: Magnetic resonance in medicine. Volume 78:Issue 2(2017)
• Page Start: 518
• Page End: 526
• Publication Date: 2016-09-08
• Subjects: T1 mapping -- T2 mapping -- balanced Steady State Free Precession (bSSFP) -- relaxometry; Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.26384
• Languages: English
• ISSNs: 0740-3194

Abstract

Abstract : Purpose: Triple echo steady state (TESS) uses the lowest steady state configuration modes for rapid relaxometry. Due to its unbalanced gradient scheme, however, TESS is inherently motion‐sensitive. The purpose of this work is to merge TESS with a balanced acquisition scheme for motion‐insensitive rapid configuration relaxometry, termed MIRACLE. Methods: The lowest order steady state free precession (SSFP) configurations are retrieved by Fourier transformation of the frequency response of N frequency‐shifted balanced SSFP (bSSFP) scans and subsequently processed for relaxometry, as proposed with TESS. Accuracy of MIRACLE is evaluated from simulations, phantom studies as well as in vivo brain and cartilage imaging at 3T. Results: Simulations and phantom results revealed no conceptual flaw, and artifact‐free configuration imaging was achieved in vivo. Overall, relaxometry results were accurate in phantoms and in good agreement for cartilage and for T 2 in the brain, but apparent low T 1 values were observed for brain white matter; reflecting asymmetries in the bSSFP profile. Conclusion: Rapid T 1 and T 2 mapping with MIRACLE offers analogous properties as TESS while successfully mitigating its motion‐sensitivity. As a result of the Fourier transformation, relaxometry becomes sensitive to the voxel frequency distribution, which may contain useful physiologic information, such as structural brain integrity. © 2016 International Society for Magnetic Resonance in Medicine. Magn Reson Med 78:518–526, 2017. © 2016 International Society for Magnetic Resonance in Medicine