CONTRAST AGENTS

PCT No. PCT/GB94/00375 Sec. 371 Date Sep. 18, 1995 Sec. 102(e) Date Sep. 18, 1995 PCT Filed Feb. 25, 1994 PCT Pub. No. WO94/19025 PCT Pub. Date Sep. 1, 1994The invention relates to compounds of formula (I): (I) wherein R1, R2 and R3 are independently selected from: (i) saturated or unsaturated fatty acyl groups, preferably having from 14 to 24 carbon atoms, more preferably of a type found in nature; or (ii) groups of formula (II): y selected from hydrogen atoms, C1-4alkyl groups and aryl groups, preferably C6-10aryl groups; n represents the integers 0 or 1; A represents either a chemical bond or a straight or branched C1-6alkylene chain and R6 is a triiodinated phenyl group which may also carry other substituents. The invention also relates to X-ray contrast media containing these compounds, as well as methods of enhancing X-ray images of a human subject wherein the contrast media are administered to the subject prior to imaging.