Ruiyang Zhao1,2, Yuxin Zhang1,2, Xiaoke Wang1,3, Timothy J Colgan1,2, Jennifer L Rehm4, Scott B Reeder1,2,3,5,6, Kevin M Johnson1,2, Diego Hernando1,2. 1. Department of Radiology, University of Wisconsin-Madison, Madison, WI, USA. 2. Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, USA. 3. Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI, USA. 4. Department of Pediatrics, University of Wisconsin-Madison, Madison, WI, USA. 5. Department of Medicine, University of Wisconsin-Madison, Madison, WI, USA. 6. Department of Emergency Medicine, University of Wisconsin-Madison, Madison, WI, USA.
Abstract
PURPOSE: Chemical shift encoded (CSE)-MRI enables quantification of proton-density fat fraction (PDFF) as a biomarker of liver fat content. However, conventional 3D Cartesian CSE-MRI methods require breath-holding. A motion-robust 2D Cartesian sequential method addresses this limitation but suffers from low SNR. In this work, a novel free breathing 2D Cartesian sequential CSE-MRI method using a variable flip angle approach with centric phase encoding (VFA-centric) is developed to achieve fat quantification with low T 1 bias, high SNR, and minimal blurring. METHODS: Numerical simulation was performed for variable flip angle schedule design and preliminary evaluation of VFA-centric method, along with several alternative flip angle designs. Phantom, adults (n = 8), and children (n = 27) were imaged at 3T. Multi-echo images were acquired and PDFF maps were estimated. PDFF standard deviation was used as a surrogate for SNR. RESULTS: In both simulation and phantom experiments, the VFA-centric method enabled higher SNR imaging with minimal T 1 bias and blurring artifacts. High correlation (slope = 1.00, intercept = 0.04, R 2 = 0.998) was observed in vivo between the proposed VFA-centric method obtained PDFF and reference PDFF (free breathing low-flip angle 2D sequential acquisition). Further, the proposed VFA-centric method (PDFF standard deviation = 1.5%) had a better SNR performance than the reference acquisition (PDFF standard deviation = 3.3%) with P < .001. CONCLUSIONS: The proposed free breathing 2D Cartesian sequential CSE-MRI method with variable flip angle approach and centric-ordered phase encoding achieved motion robustness, low T 1 bias, high SNR compared to previous 2D sequential methods, and low blurring in liver fat quantification.
PURPOSE: Chemical shift encoded (CSE)-MRI enables quantification of proton-density fat fraction (PDFF) as a biomarker of liver fat content. However, conventional 3D Cartesian CSE-MRI methods require breath-holding. A motion-robust 2D Cartesian sequential method addresses this limitation but suffers from low SNR. In this work, a novel free breathing 2D Cartesian sequential CSE-MRI method using a variable flip angle approach with centric phase encoding (VFA-centric) is developed to achieve fat quantification with low T 1 bias, high SNR, and minimal blurring. METHODS: Numerical simulation was performed for variable flip angle schedule design and preliminary evaluation of VFA-centric method, along with several alternative flip angle designs. Phantom, adults (n = 8), and children (n = 27) were imaged at 3T. Multi-echo images were acquired and PDFF maps were estimated. PDFF standard deviation was used as a surrogate for SNR. RESULTS: In both simulation and phantom experiments, the VFA-centric method enabled higher SNR imaging with minimal T 1 bias and blurring artifacts. High correlation (slope = 1.00, intercept = 0.04, R 2 = 0.998) was observed in vivo between the proposed VFA-centric method obtained PDFF and reference PDFF (free breathing low-flip angle 2D sequential acquisition). Further, the proposed VFA-centric method (PDFF standard deviation = 1.5%) had a better SNR performance than the reference acquisition (PDFF standard deviation = 3.3%) with P < .001. CONCLUSIONS: The proposed free breathing 2D Cartesian sequential CSE-MRI method with variable flip angle approach and centric-ordered phase encoding achieved motion robustness, low T 1 bias, high SNR compared to previous 2D sequential methods, and low blurring in liver fat quantification.
Authors: Mariya Doneva; Peter Börnert; Holger Eggers; Alfred Mertins; John Pauly; Michael Lustig Journal: Magn Reson Med Date: 2010-09-21 Impact factor: 4.668
Authors: Catherine D G Hines; Alex Frydrychowicz; Gavin Hamilton; Dana L Tudorascu; Karl K Vigen; Huanzhou Yu; Charles A McKenzie; Claude B Sirlin; Jean H Brittain; Scott B Reeder Journal: J Magn Reson Imaging Date: 2011-04 Impact factor: 4.813
Authors: Huanzhou Yu; Ann Shimakawa; Catherine D G Hines; Charles A McKenzie; Gavin Hamilton; Claude B Sirlin; Jean H Brittain; Scott B Reeder Journal: Magn Reson Med Date: 2011-02-24 Impact factor: 4.668
Authors: Huanzhou Yu; Ann Shimakawa; Charles A McKenzie; Ethan Brodsky; Jean H Brittain; Scott B Reeder Journal: Magn Reson Med Date: 2008-11 Impact factor: 4.668