Distribution of Cy5.5 between blood and lymphatic vessels at 1440 minutes after administration of Gd-Cy5.5. Photomicrographs obtained 1440 minutes after i.v. administration of Gd-Cy5.5. A and B are representatives of the urothelial region, whereas C and D are representatives of the adventitial region. Arrow's color scheme, as described in Figure 6. Quantification of the fluorescent signals by image analysis is presented in Figure 9.