Contrast media 3

Contrast Media in Imaging

1. IN THE NAME Of GOD Amir al- Muminin , peace be upon him, said: There is no wealth like wisdom, no destitution like ignorance, no inheritance like refinement and no support like consultation. اميرالمومنين (ع) فرمودند: هيچ بي‌نيازي چون عقل، و هيچ فقري چون ناداني نيست، هيچ ارثي چون ادب، و هيچ پشتيباني چون مشورت نيست .

2. Contrast Media Lecture 3 : C ontrast M edia iodine agent September , 2014 Prepared by: Behzad Ommani Bachelor of Radiology Master of Medical Engineering Instructor Radiology Group

3. Iodinated Contrast Agents

4. Chemical Structure Iodinated contrast media : Inorganic iodine compounds Organic iodine compounds Iodized oils Whole-body angiogram of human fetus

5. Iodized oils

6. Iodized oils Lipiodol , the first of these uses was as a contrast media used in medical radiology. The origin of this use is attributed to Jean- Athanase Sicard and Jacques Forestier . Be presented in 1922. Lipiodol is a Poppyseed oil . Current Examination Lymphangiography Hysterosalpingography Bronchography Myelography sialography

7. Lipiodol type High viscosity Descending lipiodol 40% I , high viscid than C.S.F Low viscosity Ascending lipiodol 10% I , low viscid than C.S.F

8. Disadvantages Toxicity Infection Excitation High concentration Non adherence to canal Problem in drive out after use Non absorption or slow absorption (1 ml in year)

9. substitute Ethiodil , (Ultra fluid lipiodol ) Iodipin Iodocholral Dionosil oily Myodil ( Panopaque or Ethiodan )

10. Just free Study INDICATIONS: Lymphography Diagnosis of liver lesions Embolization in association with surgical glues during vascular embolizations Prevention of iodine deficiency disorders Lymphography : 5 to 7 ml by intralymphatic injection only for opacification of a limb (the dose being adapted to the height of the patient), i.e. 10 to 14 ml for bilateral pedal lymphography .

11. Just free Study Diagnosis of liver lesions: The standard dose depends on lesion size and can vary from 2 to 10 ml per patient. LIPIODOL® ULTRA-FLUIDE is sometimes mixed with small amounts of water-soluble iodinated contrast agents. The CT scan should be performed 7 to 15 days after the selective injection to allow the LIPIODOL® ULTRA-FLUIDE to be eliminated from the non- tumoral liver tissue.

12. Organic iodine compounds

13. History As early as 1886 the first Arteriography was performed in an amputated hand . A contrast medium consisting of a suspension of chalk in water was injected into the arteries. The first water soluble iodine contrast medium was used in 1920 and was discovered because patients with syphilis in those days were treated with sodium iodide . The sodium iodide was observed in an image of the abdomen as an "increased density" of the kidneys . One especially interesting image is the photograph of the hand of a corpse, taken by means of the Roentgen rays, by Mr. Haschek and Dr. Lindenthal , in Professor Franz Exner's physicochemical institute in Vienna.

14. Applications & Type A major development occurred in the beginning of the 1950s when it was found that contrast media with three iodine atoms bound to a benzene ring had low toxicity. Water soluble iodinated contrast agents which diffuse throughout the extracellular space are principally used for angiography , during computed tomography (CT) and conventional radiography They can also be administered directly into the body cavities , for example the gastrointestinal tract and urinary tract. Iodonated contrast Non Ionic Ionic

15. Chemical Structure Iodinated contrast media compose: I Carrier molecule Benzen Ring C 6 H 6

16. Chemical Structure COOH COOH I I I Benzoic Acid Benzen Ring Tri-iodinated Benzoic Acid COOH I I I R 1 R 2

17. Chemical Structure COOH Solve ability in water Siding Chain Toxicity & Solve ability in water Note : Every change in Siding chain = change in P hysico - chemistry properties Physiologic Absorption & Excitation Iodinated contrast media can be divided into two groups , ionic and nonionic based on their water solubility

18. Ionic & Non Ionic Structure R 1 COOH R 2 R 2 R 1 R 3 / = I C=O- + R3

19. Ionic Ionic contrast media  chemically are salts of weak organic acids containing iodine. Like most salts they will split into two particles, called an anion and a cation , when dissolved in water. The anions are iodinated benzene rings, where one of the side chains is a weak organic acid (benzoic acid). They are either single benzoic rings ( monomeric contrast media) like diatrizoate , metrizoate or iothalamate , or as two linked rings ( dimeric contrast media) like iocarmate or ioxaglate . The cations are either metals like Na+ (sodium), Ca++ (calcium) or Mg++ (magnesium) or organic cations like meglumine ( methylglucosamine ).

20. Compare meglumine and sodium salts Sodium Higher water solubility than meglumin Higher iodine than meglumin Lower viscosity than megumin Meglumin Lower crick and pain than sodium Lower huart to intima

21. Non-ionic Non-ionic contrast media are contrast media that do not dissociate when solved in water. In this group, sides chain (that do not dissociate ) put instead COOH. First non ionic contrast media is Amipaque. It was a revolution in compose contrast media. But it has some disadvantages such as Cost sterilize and Non stable in solution form. Today, it has been applied in myelography

22. AMIPAQUE Discoverer Nycomed develops the world's first non-ionic X-ray contrast medium, Amipaque™ (first registration 1974), in collaboration with Professor Torsten Almén of Lund University, Sweden. This product introduced a new era in diagnostic imaging, providing excellent images with far greater safety and comfort for the patients and at the same time commanding a premium price .

23. Iodinated Contrast Media Characteristics Favorite contrast media should be have : Water solubility Osmolality Viscosity Charge

24. Water solubility Water is the most common molecule in the human body, both inside and outside the cells. In order to enable a high contrast medium concentration in extracellular water , high water solubility is necessary for contrast media in urography , angiography , etc . This water solubility is achieved in different ways by ionic and by non-ionic contrast media. Water is a polar solvent ; the water molecules are electrically neutral (equal numbers of positive and negative unit charges within the water molecule), but the positive and negative charges are distributed so that there is a surplus of positive charges (lack of electrons) at the site of the hydrogen atoms (which form positive poles) and a surplus of negative charges (excess of electrons) around the oxygen atom (which forms a negative pole).

25. Water solubility Ionic contrast media dissociate in water into electrically charged particles named ions. The positively charged ion may be a sodium ion or a meglumine ion. The negatively charged ion is the benzene derivative with three iodine atoms and a negatively charged carboxyl group. The ionic contrast media are water soluble because the positive and negative ions are attracted to the negative and positive poles of the water molecules .

26. Water solubility Non-ionic contrast media are electrically neutral like the water molecules. The nonionic contrast media are water soluble because they contain polar groups (OH-groups, hydroxyl groups) which have an uneven distribution of electrical charges with excess electrons around the oxygen atoms (forming negative poles) and a deficit of electrons around the hydrogen atoms (forming positive poles). The electrical poles in the OH-groups of the contrast media are attracted to the electrical poles in the water molecules - thus achieving water solubility.

27. Osmolality A measure of total number of particles dissolved in a fluid , usually in water . Particles can be small or large, have an electrical charge (ions from salts, acids or bases) or be electrically neutral (sugars, proteins). ( mosm /kg) Ionic contrast media are salts and split into an anion and a cation when dissolved, while non-ionic contrast media result in a solution of solution of intact molecules. This means that ionic contrast media will have 2 particles per 3 iodine atoms ("ratio 1.5 ") while non-ionic monomeric contrast media will have only particle per 3 iodine atoms ("ratio 3"), i.e. more iodine per unit.

28. Osmolality Ionic monomeric contrast media will have an osmolality of more them 7 times the osmolality of blood at the highest clinically used concentrations. Ionic dimeric contrast media have a lower osmolality but unfortunately at the cost of increased chemotoxicity . Ionic monomeric contrast media are also called high osmolar contrast media, (HOCM).+ Non-ionic monomeric contrast media consist of one benzene ring with 3 iodine atoms ("Ratio 3 "). Their osmolalities are about half that of ionic monomeric contrast media, or 2.5-3 times the osmolality of blood at the highest available concentrations. Non-ionic dimeric contrast media have two linked iodinated benzene rings. These molecules have 6 iodine atoms per particle ("Ratio 6 "). Non-ionic contrast media are more physiological than the older, ionic ones, resulting in examinations hampered by fewer and milder adverse reactions and discomfort.

29. Osmolality Ionic dimeric contrast media behave like " ratio 3 " contrast media or low-osmolar contrast media. Dimeric non ionic contrast media have 6 iodine atoms per particle (" ratio 6 "), and are isosmolar with blood and body fluids at all available concentrations .

30. Osmolality

31. Viscosity Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. Cp ( centipoise ) or mpa /sec ( mega pascal /sec ) Viscosity is measured with various types of viscometers and rheometers . For some fluids, viscosity is a constant over a wide range of shear rates ( Newtonian fluids ). The fluids without a constant viscosity ( non-Newtonian fluids ) cannot be described by a single number.

32. Viscosity depends on this factors: Liquid concentration Temperature Molecular size T ----- move ability ----- flow M.S ----- Viscosity ----- Dispose C ----- number of particle solve ----- flow Viscosity

33. Charge Protein bonding Enzyme blocking function Heart muscle Nervous system Electrolyte balance

34. Compare ionic and non ionic lower toxicity Myelography Chemical toxicity Lower allergic reactions