In vivo relaxation behavior of liver compounds at 7 tesla, measured by single‐voxel proton MR spectroscopy

Abstract

An accurate knowledge of in vivo relaxation and J-coupling behavior will significantly improve the quantification of an extended number of resolved liver metabolites at 7 T.

In vivo proton magnetic resonance spectroscopy of liver metabolites in non-alcoholic fatty liver disease in rats: T2 relaxation times in methylene protons

“…The effects of scalar coupling in lipid resonances have been acknowledged in previous studies that calculated T2 relaxation time using STEAM sequence (Hamilton et al, 2009;Gajdošík et al, 2014) and standard-and narrow-bandwidth PRESS sequences (Yahya and Fallone, 2010;Yahya et al, 2011) with short multi-TEs. As in a previously published report (Yahya and Fallone, 2010; Yahya et al, 2011), we used a standard-bandwidth PRESS sequence for a high SNR and a high spectral resolution.…”

“…For minimizing signal loss, localized point-resolved spectroscopy (PRESS) and short echo time (TE) produce better SNR of metabolite peaks and their T2 relaxation times rather than stimulated echo acquisition mode (STEAM) sequence with long TE (Yahya and Fallone, 2010). Singlevoxel 1 H MRS spectra can also confirm changes in lipid composition, including signals of methyl and methylene group resonances, with more accurate clinical results (Gajdošík et al, 2014). This requires precise, high spectral resolution for measurement of bulk lipid fractions, with a relaxation time dependent on J-coupling (also known as scalar coupling or indirect dipole-dipole coupling) (Gajdošík et al, 2014).…”

“…Singlevoxel 1 H MRS spectra can also confirm changes in lipid composition, including signals of methyl and methylene group resonances, with more accurate clinical results (Gajdošík et al, 2014). This requires precise, high spectral resolution for measurement of bulk lipid fractions, with a relaxation time dependent on J-coupling (also known as scalar coupling or indirect dipole-dipole coupling) (Gajdošík et al, 2014).…”

“…Typically, spectra obtained from in vivo 1 H MRS of liver tissue show various lipid peaks as well as choline-containing compounds from the range of 0.9-5.3 ppm (Cheung et al, 2011;Ramamonjisoa et al, 2013). It has been suggested that these possess the characteristics and can be associated with specific lipid resonances (CH 3, 0.9 ppm; (CH 2 ) n, 1.3 ppm; CH 2 C¼CCH 2 , 2.1 ppm; ¼CCH 2 C¼, 2.8 ppm;CH¼CH, 5.3 ppm) (Lim et al, 2003;Gentile and Pagliassotti, 2008;Corbin et al, 2009;Cheung et al, 2011;Yahya et al, 2011;Gajdošík et al, 2014).…”

“…A recent study investigated the effect of J-coupling on the determination of lipid composition with T2 relaxation times using localized 1 H MRS (Yahya and Fallone, 2010;Yahya et al, 2011). T2 relaxation times were assessed using a standard PRESS sequence and narrowbandwidth PRESS sequence (Yahya et al, 2011;Gajdošík et al, 2014). The results were compared at resonances of 2.1, 2.3, and 2.8 ppm at multiple TEs (Yahya et al, 2011).…”