ch. 6 Flashcards
What does ROCM stand for?
What is it used for?
Radiopaque contrast media
high density agents used to visualize low-contrast tissues in the body
ex:
kidneys
GI tract
Biliary tree
What are the most common types of ROCM?
Iodine : atomic # 53
Barium : atomic #56
What ROCM is used for vasculature and GU tract?
Iodine
uses a lower KV (under 80) because it has a lower atomic #
What ROCM is used for GI tract?
Barium
uses high kvp (over 90) because it has a high atomic #
_____ is a direct function of iodine percentage of iodine
Radiopacity
What is the difference between parenteral vs enteral
parenteral is something that is injected
and enteral is administration rectally or orally
What is ionic vs nonionic ?
ionic =
unstable atoms, more reactive inducing in body, cheaper
nonionic
safer than ionic
more expensive
Concentration of molecules per weight of water is known as_____.
Osmolality
What are the 3 properties of iodine
- Parenteral vs enteral
- ionic vs nonionic
- High osmolarity vs low osmolarity
Movement of water across the semipermeable membrane is known as_____.
Osmosis
Define osmosis
Movement of water across the semipermeable membrane
-usually done through passive diffusion
Define Osmolality
Concentration of molecules per weight of water
Measured in milliosmoles per kg of water
Measure of solute concentration in a solution is known as _____.
Osmolarity
Measured in milliosmoles per liter of solution
Osmolality is measured in ___ of water where as Osmolarity is measured in ____ of solution
- kg
2. liter
of milliosmoles per kg of water is known as _____
Osmolality
of milliosmoles per liter of solution is known as _____
Osmolarity
_____ is highly osmotic
ROCM
What occurs when contrast is placed into the bloodstream (IV)
causes extravascular fluid to be drawn into the blood stream .
Causes:
Flushing effect
cardiac effects
renal effects
What is the concern when injecting contrast through IV
Causes:
- Osmotic shifts
- Increasing blood volume
and if kidneys and heart do not work well to eliminate the excess fluid it can cause further problems.
What are 3 types of IV contrast
- High osmolarity ionic
- Low osmolarity nonionic
- Low osmolarity ionic
What is the only low osmolarity ionic contrast
Hexabrix
What occurs in the body when High osmolarity ionic ROCM is injected
- contains 3 iodine atoms per molecue
- Those atoms break down into 1 of 2
—- Radiopaque anion (- charge)
: this will absorb the x-ray)
or:
—- Once cation ( + charge)
What type of IV contrast is most
- dangerous
- and safest overall?
- High osmolarity ionic ROCM
2. Low osmolarity non ionic
____ does not dissociate ( break down) in solution
Low osmolarity non ionic
- 1 osmotically active particle for every 3 iodine atoms
____ has 6 iodine atoms and 2 dissociated particles per molecule
Low osmolarity ionic ROCM
=Hexabrix
Intravascular ROCM has poor _____
lipid solubility
therefore they do not cross cellular membrane and stay primarily in the bloodstream
Intravascular ROCM provide immediate visibility of:
- ___
- ___
- __
- Veins & arteries after rapid injection
2, Heart & major thoracic vessels
- Urinary tract
* 15 min= rapid infustion
* 30 minutes =Slow infusion
____ mostly stops ROCM from entering CNS
Blood brain barrier
When is the only time you will see contrast in the brain
when there are brain tumors because they have vascular supply
- takes 40 minuets
Kidneys become opaque in which steps : Kidney opacification
- Renal parenchyma
- Tubular structures, renal calyces a& renal eplvis
- Ureters
- Bladder
In normal renal function , ____% of IV contrast will be excreted within ____ hrs.
- 100%
2. 24 hrs.
Where does the ureter meet the bladder
UVJ
uretovesical junction
What blood work is used to check for kidney function
BUN/Creatine
____ ROCM is used just for cholangiography
*how is it eliminated?
Iodamide Meglumine
excreted primarily by the hepatic biliary system
- has been replaced with US & CT
____ ROCM is used for GI system
Enteral
What are the 3 types of enteral ROCM
- Aqueous solution
- Suspensions
- Tablets
____ is used when barium is contraindicated
Aqueous solution
ex: Gastrogafin
Describe aqueous solutions:
- Used when Ba is contraindicated
- Oral & rectal use
- Not absorbed through GI tract & stays in the lumen
- High osmolarity
____ is a typical suspension used
Barium
Describe Suspension
- ex- Barium
- excreted through feces
- Preferred for GI exams
Describe enteral tablets
- Ex: Iocetamic acid
- excreted through urine
- Used for Gallbladder
Paramagnetic contrast agents are used for:
name an example
MRI ex: Gadolinium Iron manganese * high osmolarity
What is the difference between contrast and gadolinium
Contrast does not cross the brain barrier and does not leave the vessel
Gadolinium does
____ are useful in identifying hepatic lesions and lymphatic tissue lesions
Iron compounds
( paramagnetic contrast agents )
- low osmolality
____ are used to identify cancers that have hepatocyte’s
Manganese compounds
paramagnetic compounds
Contrast used in ultrasounds is known as_____
ultrasound Microbubble agents
