Contrast Media

RT 302 – Radiologic Contrast
CONTRAST MEDIA
 CM are diagnostic agents that are instilled into body orifice of injected into the vascular
system, joint and ducts to enhance subject contrast into anatomic areas where there is low
subject contrast.
 Is a material being injected or ingested into the body for visualization of the organ under
examination.
 Substance with either a higher or lower atomic number than the surrounding tissues in
which being used to represent organs of the body which are not visualized in a routine
plain radiograph or radiography.
 Serves are a diagnostic and therapeutic aid to physician (Radiologist in particular) to
visualize certain organs or tissues.
 Are solution or gasses introduced into the body to provide contrast on radiograph
between the organ and the surrounding tissue.
Note: Ability of the CM on subject enhancement (enhance subject contrast) depends on:
 Atomic number of CM
 Atom concentration of the element or volume of the medium.
PURPOSE:
The purpose of the contrast medium is to artificially increase subject contrast in body
tissues and areas where there is little natural subject contrast. The abdominal viscera, for
example have very little subject contrast that is, it is very difficult to identify specific organs or
distinguish one organ from another. However, if a contrast agent or material is introduced into a
particular organ such as kidney or stomach, or into a vessel such as the aorta or one of its
branches, we may more readily visualize these anatomic structures and/or evaluate physiologic
activity.
TWO KINDS OF CONTRAST MEDIA:

1. POSITIVE (Radiopaque)
 Barium sulfate
 Iodine – Iodinated (both water-based and oil based) (with side effects)
 Appears white (decreased density) on the radiograph
 Composed of elements with high atomic number
2. NEGATIVE (Radiolucent)
 Air
 Other gases (nitrogen, carbon dioxide)
 Appears black (increased density) on the radiograph
 Composed of elements with low atomic number,
FOUR PHYSICAL STATES OF CONTRAST MEDIA

1. OIL
e.g.: Pantopaque, Dionosil
 Used in Myelogram and Bronchogram studies
2. TABLETS
e.g.: Biloptin (Iopodate), Telepaque (Iopanoic Acid), Cholebrine (Iocetamic Acid),
Bilisectan (Iodoalphanoic Acid), Cistobili
 Used in Gall bladder studies
3. POWDER
e.g.: Barium Sulfate (Baryntgen)
 Used in GIT, Esophogram, Barium Enema, and Small Intestinal Series (SIS)
4. LIQUID
 All iodinated and non-ionic contrast medium
 Used in IVP, Angiography, PTC, and other forms of contrast that uses liquid form
of contrast.
Methods of Administration:
1. Direct Method
 Barium Enema and Cystography
2. Indirect Method
 Oral – introduced through mouth
 PO (by mouth), through digestive system
 Parenteral – introduced via injection
 Topical
 Subcutaneous
 Intradermal
 Intramuscular
 Intravenous
 Intrathecal
FOUR VEINS WHERE YOU CAN INJECT CONTRAST MEDIA:

1. Median cephalic vein
2. Veins in the neck
3. Veins in the scalp
4. Veins in the ankle
POSITIVE CONTRAST MEDIA

1. BASO4 (Barium Sulfate)
 For examination of the Esophagus

 For small intestine
 For Upper GI Series
BARIUM SULFATE
 Is a compound; 1 atom of barium, 1 atom of sulfur and 4 atoms of oxygen.
 The most common type of contrast used in imaging of the GI system.
 Inert powder composed of crystals (colloidal suspension) that has a tendency to
clump and out of suspension (Flocculation)
 Stabilizing agents such as sodium carbonate or sodium citrate are used to prevent
flocculation.
 Atomic number of 56
 Absorbs water
 Has a high atomic number
 It is insoluble in water
 It cannot be absorbed by Gastrointestinal Tract
 It is non-toxic and has a relative contraindication in the Gastrointestinal Tract
Types:
1. COMMERCIAL – It has flavoring and additives.
(Barodense, Baroperse, Barytgen)
2. PLAIN BaSo4 – very unpalatable taste but its advantage lies in the fact that it adheres
well on the mucosa of the organ.
 It is recommended generally that barium sulfate is mixed with COLD TAP
WATER (40 degrees – 45 degrees Fahrenheit ) to reduce irritation to the colon
and aid the patient in holding the enema (increase retention of CM) during the
examination. The cold tap water reduces spasm and cramping and reported to
have anesthetic effect on the colon.
 To maximize patient comfort room Temperature water (85 degrees – 90 degrees
Fahrenheit) is recommended by most expert to produce a more successful
examination.
 RT should never use hot water for it may scald (burn) the colon mucosal lining.
Two forms of BaSo4:
1. Powder
2. Liquid
2. IODINATED FORM
 Are used in the examinations of the GI, kidneys, gallbladder, pancreas, heart, brain,
uterus, spinal column, arteries, veins, and joints.
 Atomic number of 53
Types of Iodinated Contrast:
 Ionic Iodinated CM – contrast agents salt of electrically negatively charged acids
containing iodine that ionizes in solution and causes more patient discomfort.
 (Urovision, Urografin, Angiografin, Hypaque, Cardio-conray, Uromio, Urovist,
Telebrix)
 Non-Ionic Iodinated CM – a contrast agent that does not ionize in solution and is
safer, less painful, and better tolerated by the patient.
Trade Name – Generic Name
Ultravist – Iopromide
Iopamiro – Iopamidol
Omnipaque – Iohexol
Amipaque – Matrizamide
Isovist – Iotrolan
QUALITIES OF IODINATED CONTRAST AGENTS THAT CONTRIBUTE TO

DISCOMFORT, SIDE EFFECTS, AND REACTIONS
 VISCOSITY – more viscid (thick, sticky) agents are more difficult to inject and produce
more heat and vessel irritation; the higher the concentration; the greater the viscosity;
viscosity also increases as room temperature decreases.
 TOXICITY – potential toxicity is greater with higher concentration agents and ionic
agents.
 MISCIBILITY – contrast agents should be readily miscible (able to mix) to blood.
 OSMOLALITY – Low- osmolality agents have fewer particles in a given amount of
solution and are less likely to provoke an allergic reaction.
NEGATIVE CONTRAST MEDIA

 Are substance having lower atomic number than the surrounding tissues.
 It appears black in the radiograph
Examples:
1. Air
2. Carbon Dioxide
3. Oxygen
IMPORTANT FACTORS IN SELECTING CONTRAST MEDIUM

 It must be non-toxic and must be non-toxic and must be safe both locally where
administered.
 It must produce adequate contrast

 It must have a suitable viscosity
 It must have a suitable persistence
 It must have miscibility or immiscibility as appropriate
PHYSIOCHEMICAL PROPERTIES
 Water Solubility – in vascular application an immediate dilution with blood.
 Viscosity – is a measure of the fluidity of solution.
 Measure in millipascals (mPa) per second
 The higher the viscosity of the solution, the longer it will take for the contrast
medium to be diluted by blood.
 Osmolality – Adverse reaction to CM have been related to osmolality
- a measure of the total number of particles in a solution/kg of water.
 Antihistamine – injected to patient for allergic reaction to contrast medium.
SENSITIVY TEST
 Test done to check patient tolerance to contrast medium
 To serve as test dose
 1 cc of contrast medium
SENSITIVITY TEST METHOD

1. Scleral Method – one drop of contrast is put into the sclera (white part of the eyeball)
2. Sublingual Method – one drop of contrast medium is deposited into the inferior base of
the tongue.
3. Intradermal Method – one cc (1cc) of contrast medium is just beneath the skin.
4. Intravenous Method - one cc of contrast medium is injected in the vein.
REACTION OF CONTRAST MEDIA:

1. Minor Reaction
2. Major Reaction
 Minor Reaction Includes:

1. Urticaria
2. Sneezing
3. Flushing
4. Nausea
5. Vomiting (usually no treatment is needed but reassurance and provision of a vomit

bowl.
 Major Reaction Includes:

1. Bronchospasm causing wheezing
2. Laryngeal Angioneurotic edema causing choking.
3. Vascular collapse, patient is place to pale and sweating Trudy pulse and may lose
consciousness.
4. Respiratory failure when the patient become cyanosed and may stop breathing.
5. Convulsion
6. Coma
 All these major reactions require prompt and efficient treatment to be able the
patient to survive.
3. GENERAL TYPES OF CONTRAST MEDIA

1. IODINE-BASED CONTRAST MEDIA
 Are placed in organs and blood vessels to provide contrast between the
structures and their surrounding tissues.
 It is relatively high atomic number, that is why x-ray do not pass through it.
 They can be non-absorbable oil
 It provides good radio opacity.
2. BARIUM-BASED CONTRAST MEDIA
 Are being used in Gastrointestinal Studies.
 Are heavy metallic salts and had approximately the same contrast quality as
iodine.
 It is inert dense and cannot be absorbed by the body.
 It is mixed with water and given by mouth or rectum to outline the said tract
to be studied.
 Thin or thick mixtures are used.
 Both Barium and Iodine are used as positive contrast media.
3. AIR or GAS MEDIA
 Is used as negative contrast media that is widely penetrated by x-ray.
 It provides contrast between the lung tissue, vessels masking and their air
sacks themselves.
 It is radiolucent substance that is absorbed rapidly and leave no residue.
 It may also used with barium contrast, as in air contrast for colon studies.

Contrast Media

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RT 302 – Radiologic Contrast

TWO KINDS OF CONTRAST MEDIA:

FOUR PHYSICAL STATES OF CONTRAST MEDIA

FOUR VEINS WHERE YOU CAN INJECT CONTRAST MEDIA:

POSITIVE CONTRAST MEDIA

 For examination of the Esophagus

QUALITIES OF IODINATED CONTRAST AGENTS THAT CONTRIBUTE TO

NEGATIVE CONTRAST MEDIA

IMPORTANT FACTORS IN SELECTING CONTRAST MEDIUM

 It must produce adequate contrast

SENSITIVITY TEST METHOD

REACTION OF CONTRAST MEDIA:

 Minor Reaction Includes:

5. Vomiting (usually no treatment is needed but reassurance and provision of a vomit

 Major Reaction Includes:

3. GENERAL TYPES OF CONTRAST MEDIA

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