Figure 2: CT image of a mouse before administration (a) and 2 minutes after administration of gold nanoparticles (b) and commercial iodinated contrast agent Omnipaque. It is readily apparent that the gold nanoparticles allow clear visualization of the vasculature structure revealing increased vascularization in the left leg (arrow) indicative of a tumour. Scale bar = 5mm. (From: Gold nanoparticles a new X-ray contrast agent - Hainfeld JF - The British Journal of Radiology 2006) [76].