Contrast Agents

Question 1

gas or radiopaque substances that is injected into the body, introduced via catheter, or swallowed in order to facilitate radiographic imaging of internal structures that otherwis are difficutl to visuliaze radiographically

Answer 1

contrast

Question 2

most organs and blood vessels have xray absorption to similar surrounding tissues.
used to enhance radiographic contrast pf soft tissue

Answer 2

contrast media

Question 3

an inert inorganic metallic salt of the chemical element barium
used exclusivley for radiography of the GI tract and is administered either orally or rectally

Answer 3

barium sulfate

Question 4

most palatable when cold and offered with a straw which helps it from coating the mouth

Answer 4

oral administration

Question 5

disposable eneam kits are available that include a plastic bag, enema tubing, and a rectal catheter. A liquid barium suspension may be poured inot a disposal enema bag and diluted if required, tepid water

Answer 5

rectal administration

Question 6

the principle problem with bariym complicationg the used of barium is its

Answer 6

hygroscopic nature

Question 7

most organs and blood vessels have similar xray absorption characteristic. This causes radiographic images to be only faintly distinguishable

Answer 7

iodinated media

Question 8

special water-soluble iodine compounds
most frequently used contrast agents other than barium
used when barium sulfate may be contradicted

Answer 8

water soluble (aqueous)

Question 9

unlike barium, compounds absorb into bloodstream

may be used when high risk of barium impaction is suspected

Answer 9

advantage of water soluble

Question 10

more expensive and generally produce less radiographic contrast
contraindicated for exams of esophagus or a fistula connecting esphagus to trachea
concentration of iodine determines the degree of attenuation
concentration depends largely upon the degree it will be diluted by body fluids

Answer 10

disadvanted of water soluble

Question 11

referes to the number of particles in solution per kilogram of water

Answer 11

osmolality

Question 12

human blood is about

Answer 12

300 mOsm/kg

Question 13

water soluble contrast media ranges from

Answer 13

300 mOsm/kg to more than 1000 mOsm/kg

Question 14

some contrast media molecules dissociate into two charged particles when placed in solution resulting in higher osmolality

Answer 14

ionization

Question 15

specialized contrast agents that were developed for studies in which absorption of contrast into surrounding tissues or mixing of contrast with body fluids is not desired
used ofr lymphography

Answer 15

ethiodized oils

Question 16

most commonly used oil is

Answer 16

ethiodol

Question 17

barium and iodine compounds provide positive contrast meaning they absorb more radiation than surrounding tissues and make a white or light shadow on the image

Answer 17

air contrast

Question 18

absorb less radiation and produce negative contrast or dark shadows

Answer 18

air and gases

Question 19

ordinalry used to treat hypoglycemia
causes relaxation of the smooth muscles of the GI tract
useful as a diagnostic aid in exams of GI tract beacuase it slows peristalsis and prevents cramping

Answer 19

glucagon

Question 20

most occur immediately within 30 minutes
warm feeling during injection
feel flush 1-3 minutes
metallic taste in mouth

Answer 20

mild reaction

Question 21

erythema (reddining), uritcaria (hives), bronchospasm, vasovaga

Answer 21

intermediate reaction

Question 22

anaphylactic shock 
respiratory or cardiac arrest 
seizures 
hypotension 
may be fatal

Answer 22

severe reaction

Question 23

most frequently used antihistamine
produces anticholinergic (drying) side affect
can be given orally before injection of iodinated contrast media to patients who are at risk of having an allergic reaction, IM, or IV if the patient has an allergic reaction

Answer 23

Diphenhydramine (Benadryl)

Question 24

25-50 mg orally, 10-50 mg IV and IM may be increased to 100 mg

Answer 24

adults

Question 25

12.5 - 25 mg orally

Answer 25

children over 20 lbs

Question 26

maximum safe dose in a 24 hr is

Answer 26

400 mg IM or IV

Question 27

are anti-inflammatory medications, may be prescribed before injection of contrast media

Answer 27

short acting cortichosteroids

Question 28

administered subcautanously IM or IV

stimulates the heart and sympathetic nervous system

Answer 28

epinephrine (adreneline)

Question 29

minimizes possiblity of cardiac arrest
may be administered (IV)
long acting corticosteriod
acs as anti-inflammatory agent; prevents/reduces edma of tracheobronchial tree

Answer 29

methylprednisolone (solumedrol)

Question 30

a problem imaging department encounter is

Answer 30

schdueling