Abstract: Compounds having the structure: ##STR1## wherein Q is ##STR2## n is an integer from 0 to 20; R.sup.1 is H, alkyl, fluoroalkyl, cycloalkyl, aryl, aralkyl, alkoxyalkyl or acetamidoalkyl;R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are independently H, alkyl, fluoroalkyl, halogen, hydroxy, acylamino, acetamidoalkyl, cyano, sulfonyl, carboxamido or sulfonamido;R.sup.6 is alkyl, cycloalkyl, aryl, or aralkyl; andR.sup.7 is H or --COR.sup.6 are useful as contrast agents in medical diagnostic x-ray imaging compositions and methods.

Abstract: The invention provides a novel compound having the structure ##STR1## wherein R is alkyl and R1, R2, R3 and R4 are each independently OCH3, H or I and n is 0 or 1 and m is 0 or 1.The compound is useful in a method of treating mammals either therapeutically or imaging mammals for diagnostic purposes. Useful therapeutic areas are in treating lymph nodes and tumors and diagnostic treatment is applicable to lymph nodes, tumors and in blood pool imaging. It is particularly advantageous to link an insoluble carrier molecule with a therapeutic or imaging agent to form the structure above. This makes the conjugate insoluble and thus amenable to forming nanoparticles.