Figure 2.

Relationships between hyperpolarized ¹³C-pyruvate MRI parameters as well as between HP-¹³C-MRI and proton MRI parameters. (a) The median lactate-to-pyruvate ratio was strongly correlated to the median k_PL. The volume of the tumors, represented by the area of the points on the plot, ranged from 53 to 1350 cm³ (53–908 cm³ for ccRCC). There was no correlation between ccRCC volume and lactate-to pyruvate ratio and k_PL. (b) The median lactate-to-pyruvate ratio was negatively correlated with the median diffusivity. Correlation coefficients calculated for ccRCC only. (c) Association of the median perfusion fraction from IVIM-type DWI with the median k_PL from ¹³C-MRI.