Cascade polymer complexes with at least 16 ions of an element of atomic numbers 20 to 29, 39, 42, 44 or 57-83, useful NMR or x-ray lymphography imaging.
This application is a divisional of Ser. No. 09/620,989, filed Jul. 20, 2000, now U.S. Pat. No. 6,426,059; which is a divisional of Ser. No. 09/044,254, filed Mar. 19, 1998, now U.S. Pat. No. 6,177,060; which is a divisional of Ser. No. 08/674,844, filed Jul. 3, 1996, now U.S. Pat. No. 5,820,849.
