Contrast media in radiology

The role of contrast media in radiology as the x-ray passes through the patient today will be one of three events it will happen either it will be scattered attenuated or it will pass through the patient depending on the thickness and intensity of the particular part of the patient being imaged so the beam will change from a uniform beam before that enters the patient into a beam that carries information after it enters after it exists of the patient and this information should be will be recorded on an x-ray film or whatever and in media of recording and then we read it and read that information so the different tissues if the body will attenuate the beam of x-ray to different degrees.

Radiological contrast medium so everything issues are of similar densities or they have the same or close average atomic number they will not be able to be distinguished on a radiograph so how can we see them if we cannot differentiate between them because of their close densities so we can after two factors two things can be changed in order to make them more obvious to make this little more obvious first of all as a density of organ for we can reduce it

for example by filling a hollow organ with air like the column for example and double-contrast barium enema we push air to decrease the atomic density of the organ and we can also change the average atomic number by following the organ with a liquid that is that has a higher atomic number which is usually iodine and interesting information to know is that a single dose of an x-ray contrast medium contrast that LD paste contains more than two thousand times the amount of LD in the total physiological body content so we are pushing a huge amount of iodine in order to increase the density of the atomic number of the anatomical structure.

what is a contrast medium that is any substance introduced into the body in order to make an organ or the surface of an organ or materials within the lumen of an organ visible on imaging okay so anything that we push to change the appearance of the organ is chemically called a contrast medium, for example, you can see here in this double-contrast barium enema we can see areas of increased density here which is due to the barium that we pushed to increase the atomic number of an average atom of the core and you can see an area of lucency here which is due to the air that we pushed in order to decrease the atomic number of the average atomic number of the coal so what is the use of contrast medium and there is a lot of uses for contrast medium the most important and the most frequent ones are clothing and geography.

Classification of contrast medium

 Contrast media are classified into mainly two different categories either water-insoluble like barium sulfate and water-soluble the water-soluble are also classified into two different categories ionic and non-ionic like for example gasoline and nonionic or we can classify it into law osmolarity contrast medium and high osmolarity contrast medium hokum locum and Holcomb keep in mind that the only contrast medium treating big gastrografin are very old they are not used now and very very infrequently used now while most of the contrast behaved at our width that we use and also the hokum the highest water contrast media are also very infrequently used now most of the time we use the lower smaller contrast medium so establish some historic overview of the contrast medium firstly for the first support of pacification.

water-soluble contrast medium or high or smaller contrast media are hypertonic with osmolarity of more than one hundred thousand two hundred up to two thousand million more per kg of water that's four to seven times the osmolarity of the blood and that's bad because the higher dose polarity of the contrast medium the more likely it will cause side effects so that's why we try not to use the high postmodern contrast medium and we ship to lower smaller contrast medium so all the attempts in the development of the different types of contrast, medium are being directed toward decreasing the toxicity by decreasing their osmolarity and now commission of contrast medium half or ratio of three iodine atoms per molecule or to two particles the solutions that are three to two or one points five in

1972 a new agent named dimer X appeared with a ratio of two that is less hyperosmolar to the blood so it should be less cause fewer side effects upon  further development two separate paths took place, first of all, is to combine three try an idealities benzene rings to produce an anion with a 618 atoms one cation is necessary for each molecule so we have three iodine atoms for two cations four for every one of these two currents to pro the second path is to produce a compound that does not ionized in solution and does not provide regular radiological use these cations we don't like them because they are nothing to the image but they increase the osmolarity and might cause side effects so the result of these two pathways was several non-ionic contrast medium like me paid me back ionic soul which is omnipeek and IO provides that's the ultra vest for both types of contrast media the ratio was two to better so it was a three to one in comparison with the conventional hokum that's the hyperosmolar contrast medium the new local law smaller contrast media show theoretical housing of osmolarity but because of the aggregation of the molecules in solutions the measured reduction is about one third so it should be about half but because of the aggregation in the solution is one third so the locum is one third less dense or less hyperosmolar than the hokum okay so now our attention shifted to the locum and to their use and to their development so further development of locals locum have been the nonionic dimers was called iso vest and visible these have six energy atoms per molecule with the iodine concentration can now be obtained at osmolarity and so that's good there should be either small or no okay it's one-to-one but the problem is that this contrast medium is high visitors have high viscosity at a room temperature they are thick their gel light so they need to be warmed up and to a certain temperature and then injected into the patient in addition they are a little a bit more expensive so adding the warming up problem plus the expense and higher the price they did not found a very big use in the commercial or in the everyday use of contrast medium.

contrast medium while all the rest are not ionic the clinical difference between the two is that the ionic contrast media cannot be used in some arachnoid space so you cannot you are not allowed to inject Higgs breaks as introduced intradural contrast media and you cannot make for example a myelogram using hex a breaks okay so to summarize been said all REO are soluble.

organic compounds and consider them contrast media all of them are soluble organic compounds and contains they are either ionic mono words like hokum they're hypertonic or hyperosmolar non-ionic monomers are expensive and they need to be walled up because they are very high viscosity at room temperature ionic diamonds have high protein binding with high viscosity and the non-ionic diamonds also have higher viscosity.

Purposes so what are the indications of your smaller contrast media that what is that they provide our more comfortable trio grabs at IV injections they are less toxic with a reduction in the adverse reactions keep in mind usually the intra-arterial injection lowers.

Vulcan transmitted cause fewer side effects than intravenous injection and till now no one knows why the

the intra-arterial injection is less dangerous than intravenous injections regarding the chemical reactions of the nose molar contrast medium some of them are expensive we have some risk groups.