Fig. 4. (A) MR imaging of A2780 cell pellets at 7 T. IC₅₀ concentrations of GP1 and GP2 significantly enhanced the intracellular contrast of A2780 cells (increase in R₁) compared to the untreated control cells while 1 and cisplatin had a minimal effect. (B) MR imaging of HeLa cell pellets at 7 T. IC₅₀ concentrations of GP1 and GP2 significantly enhanced the intracellular contrast of HeLa cells compared to the untreated control cells while 1 and cisplatin had a minimal effect.