1. A process for preparing a composition for X-ray examination, comprising a radiopaque agent in a carrier comprising the steps of: 1) adjusting pH of the carrier containing a radiopaque agent to 2.0-4.5, 2) heating the composition to the adjusted pH of step (1) to 60-200 ° C, 3) cooling the formulation from step (2) to 40-60 ° C 4) adjusting the pH of the heated composition of step (3) to 7,0-8,0.2. A method according to claim 1, wherein the amount of free iodine in the resulting composition is below 30 mg I / ml.3. The method of claim 1 wherein the radiopaque agent is an iodinated non-ionic monomer, dimer or trimer.4. The method of claim 1 wherein the radiopaque agent is a compound of formula (II) and its salts or optically active isomers thereof, wherein X is a straight or branched C-Calkilenovuyu moiety, wherein possibly one or two groups CHzameneny oxygen atoms, sulfur atoms or groups NR and where the alkylene group may be substituted with groups -ORv amount of up to six is hydrogen atom or a straight or branched C-Calkilnuyu group r and is hydrogen atom or an acyl functional group ikazhdy R is independently the same or different and mean triyodirovannuyu phenyl group, preferably a 2,4,6-triyodirovannuyu phenyl group, further substituted by two groups R, wherein each Ryavlyaetsya same or different and are a hydrogen atom or a nonionic hydrophilic moiety, with the proviso that at least one group R b the compound of formula (II) is a hydrophilic gruppirovku.5. A method according to claim 4, wherein X in the contrast agent, means a straight propylene, butylene or1. Способ получения композиции для рентгеновского исследования, содержащей рентгеноконтрастный агент в носителе, включающий следующие стадии:1) корректировка рН носителя, содержащего рентгеноконтрастный агент, до 2,0-4,52) нагревание композиции с откорректированным рН со стадии (1) до 60-200°С3) охлаждение композиции со стадии (2) до 40-60°С4) корректировка рН подогретой композиции со стадии (3) до 7,0-8,0
