Figure 17. Identification of benign and malignant nodes using ultra small iron oxide particles (USPIO). Axial T₂* weighted images, before and after administration of USPIO, demonstrates three lymph nodes, that are of high-signal intensity before administration of USPIO. Following administration of USPIO normal lymph nodes darken (white arrows) and malignant lymph nodes which do not take up USPIO remain high signal (black arrow) corresponding to histopathology haematoxylin and eosin stained sections demonstrating fully replaced malignant node.