(a) T2-weighted MR images (TR/TE of 4200 ms/102 ms) taken after 0 and 3.5 h of injection of 14.7 mg Fe/kg in PBS of Cy5.5 TCL-SPION at the level of tumor (320 mm3). The allograft tumor region is dashed with red circle. (b) Fluorescence images of the same mouse under same condition. An exposure time of 1 s and a Cy5.5 filter channel were used. The scale on the right indicates the relative fluorescence intensity, reprinted with permission from [56]. Copyright 2007, American Chemical Society.
