Transaxial NMR images of mice (face-down position) bearing two s.c. xenografts; left: 1411HP germ cell tumor, right: DLD-1 colon carcinoma. Images were taken without Gd-BOPTA and 10 min, 20 min and 30 min after i.v. application of Gd-BOPTA. (A): The illustration of renal pelvis was clearly enhanced directly after contrast agent injection in light grey compared to a black central area without Gd-BOPTA. The fast nephritic elimination caused a signal decrease (darker grey) already after 30 min. White arrows point at kidneys. (B): High contrast enhancement in the urinary bladder (white arrow) was identifiable as hypertense area compared to a hypotense one without contrast agent. (C): Subcutaneous xenograft tumors are visible as relative hypointense area (white arrows).