Figure 1. X-ray images mouse hind legsin vivo. (a) Before injection; (b) 2 min post tail vein injection of gold nanoparticles; (c) 2 min after equal weight of iodine contrast agent (Omnipaque®). Arrow points to leg with tumour and increased vascularity. Arrowhead points to 100 µm diameter vessel. Bar = 5 mm. (Figures 1a and 1b are reproduced with permission from Phys Med Biol [12]).