Certain 1-(3,5-disubstituted-2,4,6-triiodophenyl)-3-(polyhydroxy-alkyl)urea compounds are useful as x-ray contrast agents. Representative of this class of compounds is the compound 3-[3-(N,N-dimethylcarbamyl)-2,4,6-triiodo-5-(N-methylcarbamyl)phenyl]-1-me thyl-1-(D-gluco-2,3,4,5,6-pentahydroxyhexyl)urea.
Certain polyhydroxy-alkyl-3,5-disubstituted-2,4,6-triiodocarbanilates are useful as x-ray contrast agents. Representative of this class of compounds is the compound 1-[N-(2,4,6-triiodo-3-N,N-dimethylcarbamyl-5-N-methylcarbamyl)carbanilyl]- L-sorbose.