Contains carbon double bonded to an oxygen, single bonded to another oxygen, and a negative charge at the pH of the body
Contains nitrogen bonded to two hydrogen atoms
resembling an immune system response to foreign material (antigen)
Numbers of protons in the nuclei of the different elements
blood urea nitrogen (BUN)
BUN test can reveal whether the urea nitrogen levels are higher than normal, suggesting that the kidneys or liver may not be working properly
interactions between electrons of atoms that hold the atoms together in a stable group
Involuntary muscular contractions in bronchial tubes usually resulting from an immune system reaction
substance composed of two or more elements combined in definite ratios that give the substance specific properties
factors of a patients history or present status that indicate that a medical procedure should not be performed
nitrogen-containing waste products of metabolism excreted by the kidney's filtration system; high blood plasma levels indicate poor filtration by the kidney
Compound formed by bonding of two identical simpler molecules
leakage from a vessel into the tissue
Formation of flaky masses resulting from precipitation or coming out of a suspension or solution
molecular substance containing an amine group; causes bronchial constriction and a decrease in blood pressure
Common chemical group, part of the water molecule, containing one atom of hydrogen and one atom of oxygen; carries a negative charge (anion) when not a part of a molecule
atom or molecule having a negative charge (anion) or positive charge (cation)
common biochemical groups containing one carbon atom and three hydrogen atoms
stable groups of bonded atoms having specific chemical properties
simple molecules of a compound of relatively low molecular weight
measurement of the number of particles that can crowd out water molecules, causes most adverse reactions
Movement of water from an area of high concentration to an area of low concentration through a semipermeable membrane
relative acidity or basicity (alkalinity) of a solution
pharmaceutical compound that is attached to a radioisotope
inadequate blood flow within the body with resulting loss of oxygen and therefore energy
uniform mixture of two or more substances
nonuniform mixture of two or more substances
Five Radiographic Densities
-Air (gas) -Fat -Water -Mineral -Metal
Purpose of Contrast Study
To visualize anatomic structures that are not normally seen on a diagnostic medical image
Enhance subject contrast in anatomic areas where low subject contrast exists. Classified as negative or positive. Takes advantage of the photoelectric effect and high-atomic number elements
Photoelectric interactions result in the x-ray photon being totally absorbed and not striking the image receptor.
Type contrast agent that decrease attenuation of the x-ray beam and produce areas of increased density on the radiograph. Radiolucent Composed of low-atomic number elements
Type of contrast agent that increases attenuation of the x-ray beam and produce areas of decreased density on the radiograph. Radiopaque Composed of higher-atomic number elements
Specialty Contrast Agents
-ultrasound: Microbubbles -MR scanning: gadolinium; DTPA
Why is air not used more often as a contrast material?
Popular contrast choices and atomic numbers for each.
Barium sulfate (atomic # 56) Air/gas (atomic # 53) Oil-based iodine contrast agents Water-soluble iodine contrast agents (Iodine average atomic # 8)
List what makes a perfect contrast material.
Very-high contrast visualization Extremely low toxicity to patient Persistence in patient anatomy until imaging is completed Low cost Minimal or no side effects No residual effects within patient
Key Contrast Characteristics
- ability of agent to mix with body fluids -viscosity -ionic strength -persistence in the body -iodine content -osmolality -potential for toxicity
When should barium NOT be used?
When a perforation is suspected.
Differentiate between ionic and nonionic contrast agents.
Ionic -Dissociates into two ions; Anion (negative)/Cation (positive) -High osmolality -Adverse reactions are most often associated with ionic Nonionic -Does not dissociate into two ions and less toxic at cellular level -More water soluble (hydrophilic) -Increased solubility in plasma -Low osmolality -Warmed to increase viscosity -Less likely to cause patient reaction and is more tolerable by patients -High contrast effect resulting from number of iodine atoms per molecule -Reduced injection volumes
makes dehydrated patients are vulnerable to hypovolemic shock.
Water-Soluble Ionic Contrast Agents
List the categories of patient reactions and list examples of each.
Mild -Nausea, Vomiting, Cough, Warm feeling, Headache, Dizziness, shaking, Itching, Sweats, Urticaria (hives) Moderate -Tachycardia, Bradycardia, Hypertension, Hypotension -Dyspnea, Bronchospasm, Wheezing, Laryngeal edema Severe -Convulsions: Profound hypotension, Cardiac arrhythmias -Unresponsiveness -Cardiac arrest
Should be discontinued for 48 hrs before and 48 hrs after the use of iodine contrast media.
Radioactive material chemically attached to a pharmaceutical that is metabolized in the body (attached to a radioisotope). Detected by gamma camera in nuclear department and are effective for cellular physiology assessment.
Important when handling Radiopharmaceuticals
Time is of the essence. -Radioactive half life Be aware of contaminations. Contaminations can produce image artifacts. Contaminations increase exposure unnecessarily to patients and personnel. Two types of contamination: -External -Internal
Administered under the supervision of a...
licensed physician with proper qualifications
Leakage from a vessel into the tissue.