Fig. 7. (A) T₁-Weighted axial MR images of tumour-bearing Balb/c nude mice before (pre) and 20 min, 1 h, 3 h, 6 h and 24 h after intratumoral injection of MnO₂–Pt(iv) NPs, using a 9.4 T MR scanner. White circles highlight tumour sites. (B) Corresponding T₁ signal tumour/muscle ratio obtained using a FLASH sequence and (C) Local T₁ values of tumour and muscle tissues of mice treated with MnO₂–Pt(iv) NPs (n = 5), MnCl₂ (n = 6) and saline (n = 1), obtained using a T₁ mapping sequence on the 9.4 T MR scanner, showing mean and errors (SEM), *p < 0.045.