Quantitative ultrashort TE imaging of the short‐T2 components in skeletal muscle using an extended echo‐subtraction method. Issue 3 (3rd October 2016)

• Record Type: Journal Article
• Authors: C. A. Araujo, Ericky; Azzabou, N.; Vignaud, A.; Guillot, G.; Carlier, P.G.
• Is Part Of: Magnetic resonance in medicine. Volume 78:Issue 3(2017)
• Page Start: 997
• Page End: 1008
• Publication Date: 2016-10-03
• Subjects: ultrashort TE -- short‐T2 imaging -- skeletal muscle fibrosis -- quantitative imaging -- long‐T2 suppression; Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.26489
• Languages: English
• ISSNs: 0740-3194

Abstract

Abstract : Purpose: To introduce an ultrashort echo time (UTE) based method for quantitative mapping of short‐T2 signals in skeletal muscle (SKM) in the presence of fat, with the aim of monitoring SKM fibrosis. Methods: From a set of at least five UTE images of the same slice, a long‐ T 2 * map, a fat‐fraction map, and a map of short‐T2 ‐signal fraction are extracted. The method was validated by numerical simulations and in vitro studies on collagen solutions. Finaly, the method was applied to image the short‐T2 signals in the leg of eight healthy volunteers. Results: The imaged short‐T2 ‐signal fractions in the collagen solutions correlated with their respective collagen concentrations ( R = 0.999, P = 0.009 ). Short‐T2 tissues such as cortical bone and fasciae were highlighted in the resulting short‐T2 fraction maps. A significant fraction of short‐T2 signal was systematically observed in the skeletal muscle of all of the subjects ( 4.5 ± 1.2 % ) . Conclusion: The proposed method allows the quantitative imaging of short‐T2 components in tissues containing fat. By also having the fat‐fraction and T 2 * maps as outcomes, long‐T2 suppression is accomplished without requiring modifications to the basic UTE sequence. Although the hypersignal observed in the fasciae suggests that the short‐T2 signal observed in SKM might arise from interstitial connective tissue, further investigation is necessary to confirm this statement. Magn Reson Med 78:997–1008, 2017. © 2016 International Society for Magnetic Resonance in Medicine.