Reproducibility of hepatic triglyceride content assessment in normals using localized magnetic resonance spectroscopy

Aim: To investigate the reproducibility of measurements of hepatic triglyceride content (HTGC) in subjects with normal HTGC using localized 1H-magnetic resonance spectroscopy (1H-MRS) and a clinical 1.5T scanner. Methods: The 1H-MRS acquisition was performed with a common protocol using the whole-body coil and no respiratory triggering. An upper limit of normal HTGC of 5.56% was used. Duplicate measurements, including subject repositioning, were acquired from 23 subjects, 19 of whom had a normal HTGC. Results: The mean coefficient of variation (CV) from the duplicate measurements was 14.8% (20.5% before exclusion of a subject who was considered to be an outlier). Mean CVs of subgroups below and above the 1% HTGC limit were 19.8 and 7.0 respectively. Conclusions: The mean CV calculated in subjects with HTGC in the normal range was found to be higher than CVs of wide range HTGC groups reported in the literature. It is concluded that the reproducibility of HTGC measurements using 1H-MRS depends on the HTGC range. These findings are of importance in reproducibility studies and in estimations of required study group sizes.