N,N'-Bis(2,3-dihydroxypropyl)-2,4,6-triiodo-5-[(methoxyacetyl)amino]-N-methylbenzene-1,3-dicarboxamide ; N,N'-Bis(2,3-Dihydroxypropyl)-2,4,6-triiodo-5-[(methoxyacetyl)amino]-N-methyl-1,3-benzenedicarboxamide;