Colgan TJ, et al. - Researchers conducted this prospective study involving 11 healthy subjects and 9 patients with observed hepatic steatosis to evaluate the impact of diurnal variation on proton density fat fraction (PDFF) using chemical shift-encoded MRI (CSE-MRI), including the effect of time of day, the effect of meals and hydration status, as well as the day to day variability. For MRI-PDFF or MRS-PDFF visits, no statistically important linear trend was noted. In all six visits, repeatability was evaluated at 0.86% for MRI-PDFF and 1.1% for MRS-PDFF. The findings may show that when measuring PDFF using CSE-MRI, it is not essential to regulate the patient's time of day or fasting/fed state.