The diagnosis of osteoporosis (OP) is mainly based on orthopedic imaging approaches. The percentage fat fraction (FF%) in magnetic resonance imaging (MRI) has the potential to be used to predict and diagnose OP. In both 1-H MRS and mDIXON Quant MRI, the FF% exhibited a negative correlation with BMD. Among the three groups, the OP patients had significantly higher FF% compared to healthy subjects. In addition, the FF% according to mDIXON exhibited a positive correlation with age, and BMD showed a negative linear relationship with age. Furthermore, females had a higher FF% level compared to males. Furthermore, height was correlated with BMD but not FF%. MRI investigation (especially the FF% according to the mDIXON Quant imaging system) is useful in OP assessment. Parameters including gender and age, as well as height, are important factors for OP prediction and diagnosis.