Chemical shift‐based MRI to measure fat fractions in dystrophic skeletal muscle. Issue 1 (4th September 2013)

• Record Type: Journal Article
• Authors: Triplett, William T.; Baligand, Celine; Forbes, Sean C.; Willcocks, Rebecca J.; Lott, Donovan J.; DeVos, Soren; Pollaro, Jim; Rooney, William D.; Sweeney, H. Lee; Bönnemann, Carsten G.; Wang, Dah‐Jyuu; Vandenborne, Krista; Walter, Glenn A.
• Is Part Of: Magnetic resonance in medicine. Volume 72:Issue 1(2014:Jul.)
• Page Start: 8
• Page End: 19
• Publication Date: 2013-09-04
• Subjects: Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.24917
• Languages: English
• ISSNs: 0740-3194

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mrm24917-sec-0001" sec-type="section"> <title>Purpose</title> <p>The relationship between fat fractions (FFs) determined based on multiple TE, unipolar gradient echo images and <sup>1</sup>H magnetic resonance spectroscopy (MRS) was evaluated using different models for fat‐water decomposition, signal‐to‐noise ratios, and excitation flip angles.</p> </sec> <sec id="mrm24917-sec-0002" sec-type="section"> <title>Methods</title> <p>A combination of single‐voxel proton spectroscopy (<sup>1</sup>H‐MRS) and gradient echo imaging was used to determine muscle FFs in both normal and dystrophic muscles. In order to cover a large range of FFs, the soleus and vastus lateralis muscles of 22 unaffected control subjects, 16 subjects with collagen VI deficiency (COL6), and 71 subjects with Duchenne muscular dystrophy (DMD) were studied. <sup>1</sup>H‐MRS–based FF were corrected for the increased muscle <sup>1</sup>H<sub>2</sub>O T<sub>1</sub> and T<sub>2</sub> values observed in dystrophic muscles.</p> </sec> <sec id="mrm24917-sec-0003" sec-type="section"> <title>Results</title> <p>Excellent agreement was found between coregistered FFs derived from gradient echo images fit to a multipeak model with noise bias correction and the relaxation‐corrected <sup>1</sup>H‐MRS FFs (y = 0.93x + 0.003; R<sup>2</sup> = 0.96) across the full range of FFs. Relaxation‐corrected <sup>1</sup>H‐MRS FFs and imaging‐based FFs were significantly elevated (<italic>P</italic> < 0.01) in the muscles of COL6 and DMD subjects.</p> </sec> <sec id="mrm24917-sec-0004" sec-type="section"> <title>Conclusion</title> <p>FFs, T<sub>2</sub>, and T<sub>1</sub> were all sensitive to muscle involvement in dystrophic muscle. MRI offered an additional advantage over single‐voxel spectroscopy in that the tissue heterogeneity in FFs could be readily determined. Magn Reson Med 72:8–19, 2014. © 2013 Wiley Periodicals, Inc.</p> </sec> </abstract>