Steatosis and steatohepatitis (NASH) may be attenuated by calorie restriction and/or exercise if intervention is early enough. However, steatosis/NASH is generally asymptomatic, and when clinical signs are observed, simple lifestyle interventions are no longer effective. Thus, there is a real clinical need to detect steatosis/NASH early but also to monitor putative therapies. A methionine-choline-deficient diet leads to NASH in rats, that is readily reversible when rats are placed back on a methionine-choline replete diet. This model will be used to assess the ability of MRI to detect the induction of, and reversal of steatosis, in vivo.