Contrast Agents

contrast media

a diagnostic agent that can be injected using several different routes into the vascular system, joints, ducts & organs to enhance subject contrast in anatomic areas where low subject contrast exists

licensed practitioner

who can administer contrast agents w/in the ASRT scope of practice?

ingested/oral

contrast will be swallowed or given via gastrointestinal tube

by mouth

what does PO mean?

safest, most economical & convenient way of giving medication

what are the advantages of oral route?

rectal

reasonably convenient & safe when oral routes cannot by used

unpredictable retention of drug

absorption is erratic

what is the disadvantage of rectal route?

parenteral

administered by injection or by a route other than the GI tract

anything done by injection

usually syringe & needle or catheter & container

drugs must be sterile, absorbable & nonirritating

90

what is the degree of the intramuscular parentral route?

45

what is the degree of the subcutaneous parentral route?

15-30

what is the degree of the intravenous parentral route?

5-15

what is the degree of the intrafermal parentral route?

intravenous

directly into bloodstream

through a vein, allows pt to respond rapidly to medications

used for delivering emergency meds when rapid response is necessary

hypodermic needle

butterfly set

IV catheter

what can venipuncture be done w/?

intra-thecal

parentral route

into spinal subarachnoid space

myelogram

what is an example of a intra-thecal parenteral route?

intra-articular

parenteral route

into joint space

can inject steroids into space or contrast

arthrogram

what is an example of a parenteral intra-articular route?

intra- arterial

parentral route

into artery

arteriogram or angiography

what is an example of a intra-arterial parentral route?

extravastion

leakage of the contrast (vesicant) into the surrounding tissues

remove the needle, apply pressure & COLD compress to reileve discomfort

what do you do if extravastion happens?

enteral

what type of route is ingested (oral) & rectal (retrograde)?

paraentral

what type of route are intravenous, intrathecal, intra-articular & intra-arterial?

medication

dose

pt

time

route

documentation

what are the 6 rights of drug administration?

3

how many times do you read the label before adminstration medication?

check dosage

spelling

expiration dates

what are the main things you should look at when grabbing medication?

contrast/medication name

strength

amount/quantity

expiration date & time

when transferring medication into another container or syrgine, what must be read out loud?

ask pharmacist or colleague to double check calculation of dose

when giving the dosage of medication/contrast to pt, what is a safety percaution you can do?

ID bracelet

name

DOB

how do you identify a pt before giving medication/contrast?

each time a medication is given

when do you verify pt’s identification?

physician/practitioner

who is reponsible for ordering drug & determining time of administration?

do not leave pt unattended

once a medication/contrast is given, what must you do?

physician

who tells you the specific route of the medication/contrast?

name & dose of medication

route of administration

date & time

if the pt refuses

adverse effects or errors

what must be document when giving medications/contrast?

circulates through the heart & passes into the arteries

through capillaries, then into veins & back to the heart

kidneys & liver eliminate the contrast from the blood

where dose contrast go?

absorption cahracteristic of the tissues

technical factors used

characteristics of the image receptor

automatic image processing

contrast media agents used

what are factors that affect the radiographic densities?

atomic numbers

the body absorbs x-ray phtons dependent on the various tissues

tissues w/ higher atomic numbers absorb more x-ray photons then tissues w/ the low atomic numbers

contrast studies

diagnostic agents are administered into body orifices or injected into vascular system, joints, or ducts to enhance subject contrast in areas where it is low

radiolucent

what is negative contrast?

radiopaque

what is positive contrast?

negative contrast agent

decrease attenuation

low atomic #’s

appear dark - increase radiographic density = black

radiolucent media

gas-filled microbubbles (U/S)

gas-producing tablets

soda water (EZ gas)

carbon dioxide crystals

what are some types of gaseous compounds?

air can cause an emboli

lodge in blood vessels, pain & loss of O2 to the area

what are some complications w/ negative contrast agents?

positive contrast agent

increase attenuation

hight atomic #’s

appear light (decrease radiographic density = white)

radiopaque media

metallic salts

barium sulfate & gadolinium compounds

organic iodides

ionic contrast agents & nonionic contrast agents compounds

radiation quality (kVp)

image contrast

radiographic object (pt)

what is contrast influenced by?

6.46

what is the atomic # of fat?

7.51

what is the atomic # of water?

7.64

what is the atomic # of muscle?

12.31

what is the atomic # of bone?

high atomic #

nontoxic

cheap & plentiful

excreted

what are ideals for contrast agents?

barium sulfate

inert powder composed of crystals

used for examining digestive system

nonabsorption

suspension

56

what is the atomic # of barium sulfate?

cause constipation or obstruction

increase H2O absorption by the colon = excessive fluid = hypervolemia (fluid overload), pulmonary edema (fluid in lungs

allergic reactions

vaginal rupture

what are some barium adverse reactions?

peritonitis

colon perforation

extravasation into abdominal cavity

due to incorrect placement of catheter prior to lower GI exam

how does barium study cause a vaginal rupture?

risk of constipation = pt are informed to drink plenty of fluids

what are some barium post study info for pts?

weight/weight

weight/volume

what are the barium concentration do we use?

weight/weight

indicates the # of grams of active ingredient in 100g of product

used for powered barium

weight/volume

indicates the # of grams of active ingreident found in a volume of 100mL

used for liquid barium

weight of Ba compared to the total volume of bA mixutre

increased weight = more dense (thick)

the degree & exten of contrast required in the area under examination

what is barium concentration dependent on?

air

what radiolucent media is commonly used?

iodinated contrast media

additives to prevent iodine atoms from being removed from contrast molecules - citrate & calcium disodium edetate

53

what is the atomic # of iodine?

oil & water soluble

what are the types of iodine?

oil iodine

injected in ducts, never vessels

not ingested

water soluble iodine

injected in vessels &/or ducts

ingested

shows organ flow/function

barium

what radiopaque media commonly used?

iodine oil-based media

made from fatty acids commonly found in plants & animals

viscous - friction - thicker

brochography

bronchi

lymphography

lymphatic system

dacrocystohgraphy

tear ducts

myelograms

spinal canal

siaolgram

salivary glands

osmolality

measure of total # of dissolved particles in a solution per kg of water

determines osmotic pressure, which controls the movement of water in the body

higher media = larger # of particles in a solution = pulls water towards them

90-120

what is the kVp range for barium?

90 or below

what is the kVp range for iodine studies?

homeostasis

any self-regulating process by which biological systems tend to maintin stability while adjusting to conidtions that are optimal for survival

more absorption

higher atomic # = what?

ionic contrast

in water or blood plasma, it dissociates into 2 molecular particles upon injection

1 particle = negative charge

1 particle = postive charge

anion

negatively charged ion

radiopaque part - containing organic molecule

diatrizonate

iothalamate

what are examples of anion particle?