Fig. 4

In vivo PAI and MRI of HepG2 tumors. a, b In vivo PAI of HepG2 tumors at various timepoints post-injection of FePt nanoprobes (scale bar: 1 mm) (a), and the corresponding relative photoacoustic intensities in the tumor area (b). (c, d) In vivo T1WI of HepG2 tumors at various timepoints after intravenous injection of FePt nanoprobes (scale bar: 1 cm) (c), and the corresponding T1 SBRs of the tumor area (d). e, f In vivo T2WI of HepG2 tumors at various timepoints after intravenous injection of FePt nanoprobes (scale bar: 1 cm) (e), and the corresponding T2 SBRs of the tumor areas (f). g) Ratios of T1 SBR to T2 SBR. (*P < 0.05, **P < 0.01)