CONTRAST MEDIA Positive CM Negative CM Ba.sulfate Iodine compound Air (O2, CO2) Water soluble CM Solid CM Oily CM Ionic CM Non-ionic CM Tablets or capsules powder

Water soluble contrast media Water soluble contrast media for IV injection Urographin (most popular). Isovist Telebrex Water soluble contrast media for oral use Gastrographin. Water soluble CM for intra thecal injection (Myelographic contrast). Iohexol (Omnipaque). UNIT VII

Water soluble CM for IV injection Intravenous Urography. All CT examination using contrast material. - CT chest (while fasting). - CT abdomen and pelvis. - CT angiography of any vessel. Carotid Pulmonary Aorta Lower limb vessels Coronary vessels. UNIT VII

Water soluble contrast media for intra- thecal injection Cervical myelography. Dorsal myelography. Lumber myelography. N.B. The usage of myelography is so limited because the great advances of MRI UNIT VII

Water soluble contrast media used for any canal or duct opacification Evaluation of the salivary gland (Sialography). Evaluation of the Urethera and Urinary bladder (Cysto urethrography). Evaluation of the uterus and tubes (Hystero salpingiography). Injection of any external opening in the skin (Fistulography). H.S.G UNIT VII

Vascular And Urographic C.M. They are organic iodine compounds. Iodine has an atomic number of 53 * They form the major positive contrast media used in diagnostic imaging * They are categorized as: (a) high osmolality, (b) low osmolality contrast media

What is Osmolality? Osmolality is a variation of molality that only takes into account solutes that contribute to a solution's osmotic pressure. In chemistry, the molality, of a solution is defined as the amount of substance (in mol) of solute, , divided by the mass (in kg) of the solvent, (not the mass of the solution). It is measured in osmoles of the solute per kilogram of water. UNIT VII

The high osmolality contrast media - (HOCM) have very high osmolalities e.g., of 1200-2000 mosmo /kg (about 4-7 times the osmolality of cell and tissue fluid )and are hypertonic. -They are solution of the sodium and /or meglumine salts of monomeric tri- iodinated substituted benzoic acids e.g., Diacetrizoic, iothalmic, or metrizoic acids

-These salts are dissociate, completely in solution, each molecule providing one cation and a large organic iodine containing anion. Hence another name for these HOCM is “Ionic contrast media”. Both anion and cation have equal osmolar effects but only the anion is radiopaque -Many of the adverse effects of contrast media are the result of high osmolality.

The Low Osmolality Contrast Media The low osmolality contrast media (LOCM) have an osmolality ranging from 291-702 mosm /kg. These are non- ionic dimmers which have a ratio of six iodine atoms for each molecule in the solution. The terms low osmolar and non-osmolar are not synonymous. The major difference between the two groups is that ionic contrast media cannot be used in the sub-arachnoids space.

The osmolality was eliminated or reduced by reducing the number of the cation in these contrast media which does not contribute to the radiopacity, but is responsible for up to 50% of the osmotic effect (Toxicity of C.M.). The ratio of iodine atom in the molecule to the number of particles in solution is 3:2 for HOCM compared to 3:1 in LOCM. The LOCM include iohexol (Omnipaque), iopamidol (isovue), iopromide, and ioversol.

Ionic and Non Ionic water soluble CM for IV injection XENETIX®300 Xenetix® (lobitridol) is a non-ionic, low osmolality iodinated contrast agent indicated for whole-body imaging in adults and children. It is also indicated for conventional intravascular and cardiac imaging. يستخدم عندما يكون هناك حساسية لدى المريض من اليود المؤين هنا يكون اليود مركب وليس أيون حر TELEBRIX® Telebrix® (loxitalamate) is an ionic, high osmolality iodinated contrast agent, which is available over a broad range of concentrations with vascular and non-vascular indications.

Intravenous Urography Renal colic Renal pain Renal mass Hematuria Normal IVU The collecting systems ureter and bladder UNIT VII

Urographic pathology Horseshoe kidney UNIT VII

Delayed contrast excretion due to ureteric stone Renal stone Renal cell carcinoma UNIT VII

CT Renal angiography Cystogram Evaluation of the bladder Before micturation UNIT VII

Cytogram before and after voiding UNIT VII

Factors Influencing The choice of Contrast Media 1. Appropriateness: The C. M. chosen should be appropriate for the necessary examination or investigation e.g. - Barium-sulphate for Barium meal, - Omnipaque for myelogram 2.Acheivable radio-opacity: The contrast medium should provide the desirable degree of radio- opacity.

Barium meal myelogram

myelogram

3.Toxicity and /or side effects: The contrast medium must be safe and non-toxic both locally where it is administered and elsewhere in the body that it may reach. i.e. it should not produce any unwanted effect on the body in general. 4. Viscosity: For some examinations such angiocardiography a relatively low viscosity is desirable to enable rapid injection of a large volume of contrast medium .

side effects Toxicity Viscosity angiocardiography

For examinations where the contrast medium is injected and stays in the organ or dissipates slowly from it (e.g. H.S.G.) , a more viscous contrast medium can be used. 5. Cost: The c. m. should be reasonably priced and affordable. 6. Persistence: Some contrast may remain in the body for several years and are thus of use in assessing progress by continuing to show any change in the size of the contrast filled lesion without further injection.

7. Miscibility: For some examinations like cyst puncture, the contrast should mix with the fluid into which it is injected. In other words it should mix with the body fluid e.g. CSF and urine ).

Reactions to contrast media Flushing (1) Minor reaction:- Nausea Urticaria. Sneezing. Flushing. Nausea. Vomiting. Sneezing No, treatment is usually required.

(2)Major reaction:- Requires treatment. They are life-threatening, severe reactions which cause real danger and for which swift treatment is so important. Most such reactions occur within five minutes of the injection and the great majority within thirty minutes so that a doctor should be at hand for this period whenever an injection of contrast media has been given.

Major reactions include:- (a) Bronchospasm-wheezing. (b) Laryngealالحنجرة angioneurotic oedema تضخم. (c ) Vascular collapse and lose of consciousness (d) Cardiac arrest. (e) Respiratory failure. Treatment of major reaction dependent on immediate availabity of the following:- *The necessary expertise.

The role of the Radiological Technologist in case of emergency 1) Know how to call for help without leaving the patient and the room. 2) Know where the nearest supply of oxygen and how to administer it. 3) Know how to call the “crash team” and to communicate with the radiologist. 4) Know where the emergency drugs and the key to the drug cupboard/trolley.

BASIC & Advanced life supports and emergency equipment. Basic life support (CPR i.e. cardio-pulmonary Resuscitation. Advance life support (Endotracial and Defibrillator). Emergency equipment:- 1) Oxygen and equipment for artificial ventilation. 2) Drugs. 3) Equipment.