RT302 - Lesson 1: Contrast Media

Radiographic Contrast Media

Refers to substance administered to a patient to artificially increase the attenuation of the x-ray beam, creating a clear visual difference on the image where tissues would otherwise look similar.

Contrast Media

Provides additional contrast for visualization of atomic details, used as an aid for imaging internal organs. It defines subtle difference in subject contrast and is high in atomic number.

Radiopaque and Radiolucent

What are the two types of contrast media?

Ingested

Retrograde

Antegrade

Intrathecal

Parenteral

What are the 5 methods in administering contrast media?

Ingested

This administration method is taken orally.

Retrograde

This administration method means to go against the flow.

Antegrade

This administration method means to go towards the flow.

Intrathecal

This administration method is through the spinal canal.

Parenteral

This administration method is through IV or intrathecal, injected into the blood stream. Refers to any administration route that bypasses the digestive system.

Air

Oxygen

Carbon Dioxide

Nitrousoxide

What are some examples of negative contrast?

Barium (Ba - 56)

Iodine (I - 53)

Bromine (Br - 35)

What are some examples of positive contrast agents?

Barium Contrast or Barium Sulphate

This contrast agent has an atomic number of 56, is non-water soluble, and is used in the alimentary track or GI only.

Barium Enema

Used as large bowel investigation.

Barium Swallow

Barium used in esophageal investigation.

Barium Meal

Barium is used in stomach investigation.

Barium Follow Through

Barium is used in stomach and small bowel investigation.

Barium

Suspension may cause allergy, after exam may solidify & difficult to evacuate.

Patient should increase fluid intake and mild laxatives

What should the patient do before a barium examination?

Extravasation of contrast into peritoneum

What complications can barium examination have?

Iodinated Contrast or Iodine

This contrast agent has an atomic number of 53, is water soluble, liquid/powder, is used in GI track (oral or rectal), IV, and Intrathecal administration, is also oil based.

Angiography

Venography

VSUG (Voiding Cystourethrography)

HSG (Hysterosalpingogram)

IVU/IVP (Intravenous Urography/Pyelography)

RGP (Retrograde Pyelography

Iodine contrast agents are used for the following:

Water Based and Oil Based

What are the two types of iodinated contrast?

Water Based Iodine Contrast

This type of iodine contrast is injected, used in vessels/ducts, ingested, and used for organ function flow.

Oil Based Iodinated Contrast

This type of iodine contrast is injected, never used for vessels, only ducts, and is not ingested.

Ionic Iodinated Contrast and Non-Ionic Iodinated Contrast

What are the two types of water based/soluble contrast media?

Ionic Iodinated Contrast

This water based/soluble contrast media is used in early development for contrast, cause more patient allergic reaction, has high osmolality (high presence of cation & anion).

Non-Ionic Iodinated Contrast

This water based/soluble contrast media causes less patient allergic reactions and has low osmolality.

Water Based/Soluble Contrast Media

Is primarily used to visualize vessels, and changes in tissues on radiography and CT, but can also be used for tests: Urinary Tract, Uterus, and Fallopian Tubes.

Cost and Allergic Reaction of Patients

What is the main difference between the two types of water based/soluble contrast medias?

Iodine Contrast Agents

They are relatively nontoxic in most cases, but certain patient may exhibit reactions of varying severity, especially to agents containing iodine.

Diatrizoate Sodium (Hypaque)

Iothalamate Meglumine (Conray)

What are some examples of ionic iodinated contrast agents?

Gadodiamide (Omniscan)

Iodixanol (Visipaque)

Iopamidol (Isovue)

Iopromide (Ultravist)

Ioversol (Optiray)

What are some examples of non-ionic iodinated contrast media?

Non-Ionic Contrast Media

This contrast produces fewer adverse drug reactions, the ionic compounds have a greater tendency to pass the barriers of tissues w/c leads to less side effects. One drawback is their cost.

1975

When did the first non-ionic contrast medium, metrizamide become available?

1980s

When was non-ionic contrast media succeeded by a second generation?

Selective Localization

Is the property of organic iodine w/c means that a contrast media introduced to the body will collect at a certain point in the body.

Urinary System

Where are positive contrast agents mostly eliminated or removed from the body?

Viscosity

Chemotoxicity

Iodine Contents

Miscibility

Persistences

What are the important physical character Of contrast agents?

Viscosity

The quality of fluid caused by the adhesion of the molecules which it resists.

Chemotoxicity

The effects that causes adverse reaction or death.

Iodine Content

Pertains to the type of iodine used, ionic or non-ionic.

Miscibility

Ability of substance to mix with other substance.

Persistences

Ability of a contrast agent to remain in the body long enough to be recorded on the film and expelled from the body rapidly.

Hyperosmolality

What is the main root of major reactions that occur during ionic organic iodine contrast radiographic procedures?

Nephrotixicity

Refers to toxicity to the kidneys, a major consideration for clinicians when requesting tests which use an iodine-based contrast media.

Mild Allergic Reaction (No Treatment Necessary)

Reaction symptoms include:

Warm Flush

Metallic Taste

Vomiting

Pruritus (Itching)

Diaporesis (Sweating)

Moderate Allergic Reaction (Treatment is necessary, but no intensive care)

Reaction symptoms include:

Facial Edema (Facial Swelling)

Severe Urticaria (Hives)

Slight Wheezing (Dyspnea)

Bronchospasm

Severe Allergic Reaction (Life-Threatening, intensive care necessary)

Reaction symptoms include:

Respiratory Arrest

Cardiac Arrest

Pulmonary Edema

Lost of Consciousness

Convulsion

Severe Laryngeal and Bronchospasm

Hypotensive Shock