El Rafei M, et al. - In this prospective study, researchers intended to determine the degree of variation of semi-quantitative and permeability parameters on DCE-MRI of normally appearing striated muscles. For this investigation, they performed dynamic contrast-enhanced MRI of the right hip in 20 women and 24 men. The intra-observer agreement was considered to be good for free-form ROI (region of interest) and moderate for elliptical ROI. On the other hand, the inter-observer agreement was considered to be bad in both cases. The data presented in this work showed a considerable variation in resting muscle perfusion parameters and this could lead to errors in the analysis of muscle DCE-MRI studies or oncologic/non oncologic studies using muscle as a referential. In most of the perfusion parameters evaluated, there was a high inter-individual variation.