Contrast Media Flashcards
What are the two types of contrast media?
- Radiolucent (negative)
- Radiopaque (positive)
How many types of contrast media is there?
2
what type of contrast media is radiolucent?
Negative
What type of contrast media is radiopaque?
Positive
What is the purpose of contrast media?
- Visualize anatomic detail
- Distinguish between radiographic densities in anatomic tissues
What is contrast media?
Diagnostic agents that are instilled into body orifices or injected into the vascular system, joints, and ducts to enhance subjected contrast in anatomic areas where low subjects contrast exists
How many routes of administration are there for contrast media?
4
What are the routes of contrast administration?
- Oral
- Rectal
- Retrograde
- Parenteral (Intravenous, Intra-arterial, Intrathecal)
Where is the oral route taken?
Ingested by mouth
Where is the rectal route taken?
Administered rectally
Where is the retrograde route taken?
Administered against the normal flow
Where is the parenteral route taken? What are the routes?
- Administered by injection using a needle
- Intravenous (Administered into a vein)
- Intra-arterial (Administered into an artery)
- Intrathecal (Administered into a sheath)
What are some exams that are taken retrograde?
- Cystogram
- VCUG
- Barium enema
What are some exams that are taken rectal?
Barium enema
What are some exams that are taken oral?
- Upper GI
- Esophagram
- Rehab swallow study
What are some exams that are taken Intravenous (parenteral)?
IVU
What are some exams that are taken Intra-arterial (parenteral)?
Arteriogram
What are some exams that are taken Intrathecal (parenteral)?
Myelogram
What are some examples of negative contrast media?
- Gas (Air)
- Gas-producing tablets
- Air-producing crystals
- Carbon dioxide
What does negative contrast media look like on radiographs?
Dark
What is negative contrast media composed of?
Elements with low anatomic numbers
In negative contrast media x-ray photons are _______ through _______ contrast media
- Easily transmitted or scattered
- Radiolucent
What are examples of positive contrast media?
- Barium sulfate (aka Barium)
- Water-soluble iodinated contrast
- Oil-based iodinated contrast
What does positive contrast media look like on radiographs?
Light
What is positive contrast media composed of?
Elements with high anatomic numbers
In positive contrast media x-ray photons are _______ by _______ contrast media
- Absorbed
- Radiopaque
Is barium radiolucent or radiopaque?
Radiopaque
What is the atomic number of barium?
56
What is the chemical formula for barium?
BaSO4
(1 atom of barium + 1 atom of sulfur + 4 atoms of oxygen)
What is barium sulfate?
A compound
Does barium sulfate dissolve in water?
No
Barium sulfate is ________ because its ______ in water
- Relatively inert
- Insoluble
Colloidal suspension is not a ______
Solution
What does barium sulfate mixed with create?
Colloidal suspension
What is used to create a colloidal suspension?
Barium sulfate and water
What is used to increase palatability in barium sulfate?
Flavorings and sweeteners
What will happen in a colloidal suspension when particles are left to sit for too long?
The particles suspended in water will settle out
How do you make thin barium?
1 part barium sulfate to 1 part water
What is the consistency of thin barium?
Thin milkshake
What happens when the thin barium mixture is cold?
The chalky taste is reduced
What does the flow of thin barium through the GI tract depend on?
- Suspending medium & additives
- Temperature
- Consistency
- Patient condition & GI tract
What does w/v mean?
Weight to volume
What is the w/v ratio of barium sulfate to water (thin barium)
30-50%
How is thick barium created?
3-4 parts of barium sulfate to 1 part water
What is the consistency of thick barium?
Cooked cereal
What is the w/v ratio of barium sulfate to water (thick barium)?
up to 250%
Which kind of barium is difficult to swallow?
Thick barium
Thick barium is more ______ than thin barium
Difficult to swallow
What kind of barium is better suited for the esophagus?
Thick barium
Thick barium is well suited for the _____
Esophagus
Why is thick barium better suited for the esophagus?
It descends slowly and coats the mucosal lining
Which kind of contrast descends slowly and coats the mucosal lining?
Thick barium
What are other forms of barium?
- Barium paste
- Barium pills
What are barium pills used to evaluate for?
Strictures in the esophagus
How are barium pills taken?
Orally
Which ways can barium paste be taken?
Orally & rectally
What can barium paste be used to evaluate for orally?
The function of the esophagus
What can barium paste be used to evaluate for rectally?
The function of the rectum
What exam is used to evaluate rectum function?
Defecography
How many contraindictions are there for barium?
11
What are the contraindictions for barium?
- Suspected colon obstruction
- Gastrointestinal perforation
- Transesophageal fistula
- Obstructing lesion of the small intestine
- Inflammation or neoplastic lesions of the rectum
- Pyloric stenosis
- Paralytic ileus
- Gastrointestinal hemorrhage
- Toxic megacolon
- Recent gastrointestinal biopsy or surgery (within 3-5 days)
- Pre-op or pre-endoscopy
In what cases should water-soluble iodinated contrast media be used?
If theres any chance that contrast will escape into the peritoneal cavity
What kind of contrast should be used if theres any chance that contrast will escape into the peritoneal cavity?
Water-soluble iodinated contrast media
What are some examples of Water-soluble iodinated contrast media?
- Gastrografin
- Gastroview
What kind of contrast media is gastrografin or gastroview?
Water-soluble iodinated contrast media
What is the most common complication of barium administration?
Constipation
What are some complications of barium administration?
- Constipation
- Perforation (extravasation into the abdominal cavity)
- Vaginal rupture by incorrect placement of the catheter for lower GI exams (very rare)
- Fluid overload resulting from water absorption from the colon
- Aspiration into the lungs (Can result in barium pneumonia)
- Allergic reactions
What can constipation due to barium administration lead to?
Obstruction
What should you do after the patient recieves barium to avoid complications?
To drink plenty of fluids
What can barium aspiration into the lungs result in?
Barium pneumonia
Should a water-soluble iodinated contrast be used if a patient is sensitive to iodine?
No
What is a water-soluble iodinated contrast used for?
To opacify the GI tract
Which contrast is used to opacify the GI tract?
Water-soluble iodinated contrast
Which way can water-soluble iodinated contrast be taken?
Orally or rectally
What are some examples of water-soluble iodinated contrast?
- Gastrografin
- Gastroview
What is the atomic number of iodine?
53
What does water-soluble iodinated contrast contain?
Iodine
What will happen if water-soluble iodinated contrast leaks into the peritoneal cavity?
The body will absorb it
Can barium sulfate be absorbed by the body?
No
What kind of taste does water-soluble iodinated contrast have?
Bitter
Water-soluble iodinated contrast can be ______ or _____
- Used as is
- Diluted with water
What contrast moves faster through the GI tract?
Water-soluble iodinated contrast
How fast does water soluble iodinated contrast clear the stomach?
1-2 hours
How fast does water soluble iodinated contrast outline the colon?
4 hours
In what case should water-soluble iodinated contrast not be used?
If patient is sensitive to iodine
What are some technologist responsibilities when it comes to giving the patient contrast?
- Take patient history
- Check lab values to assist kidney function
- Room set up
- Assist radiologist
- Obtain requested radiographs
- Present images to radiologist before letting the patient leave
- Give post-procedural instruction to the patient
- Clean up room
What does BUN stand for?
Blood urea nitrogen
What is the normal BUN range for males?
8-24 mg/dL
What is the normal BUN range for females?
6-21 mg/dL
What is the normal range for creatinine levels?
0.6-1.2 mg/dL
Many facilities will not inject patients with a creatinine level of ________
1.5
What does GFR stand for?
Glomerular filtration rate
What is the normal GFR range for normal kidney function?
90-130
What is the normal GFR range for moderate kidney damage?
30-60
What is the normal GFR range for severe kidney damage?
15-30
What is the normal GFR range for kidney failure?
0-15
What is needed to increase penetrability?
Higher kVp
Higher kVp is needed to ________
Increase penetrability
________ is determined by the atomic number of the elements used in contrast media?
X-ray attenuation
X-ray attenuation is determined by the ____________ used in contrast
atomic number of the elements used in contrast media
What kVP is used in single-contrast barium studies?
110-120 kVp
What kVP is used in double-contrast barium studies?
90 kVp
What kVP is used in injected iodinated-contrast studies?
80-85 kVp
What kind of contrast is rarely used?
Oil-based iodinated contrast media
What has oil based contrast been replaced with?
Non-ionic iodinated contrast media
What is oil based contrast made from?
Fatty acids found in plants and animals
Oil based contrast is _____ in water and doesnt _______
- Insoluble
- Flow easily
Oil based contrast decomposes when exposed to?
Light, heat or air
What happen when oil based contrast is exposed to light, heat or air?
Decomposes
What can oil based contrast be used for?
- Lymphangiography (lymphatic system)
- Bronchography (bronchial tree of lungs)
- Sialography (salivary glands)
- Dacrocystography (tear ducts)
- Hysterosalpingography (female reproductive system)
- Myelography (spinal cord)
What are the common side effects for injectable iodinated contrast?
- Temporary hot flash
- Metalic taste in mouth
What is extravasation?
The discharge of escape of fluid from a vessel into the surrounding tissue
What is the discharge of escape of fluid from a vessel into the surrounding tissue called?
Extravasation
What can occur with injected iodinated contrast?
Extravasation
What can occur due to extravasation?
Acute, local inflammation
What can extravasation lead to?
Ulceration and tissue necrosis
how do you treat extrvasation?
With a cold compress followed by a warm compress to relieve pain and promote reabsorption of extravasated contrast media
Isomolal results in a _________ solution
Isotonic
Isomolal contains the _____________
Same number of particles as blood plasma
Does non-ionic isomolal contrast cause fewer adverse reactions?
Yes, theoretically
How many atoms of iodine does non-ionic isomolal contrast have?
6 atoms per two particles
Non-ionic isomolal contrast has ______ the iodine concentration
Twice
How is non-ionic isomolal contrast different from others?
Half the dose is needed compared to others
What is an example of non-ionic isomolal contrast?
Visipaque
What are some examples of lower-osmolality contrast?
-Omnipaque
- Isovue
- Amipaque
- Optiray
What kind of contrast do radiology departments exclusively use?
Non-ionic iodinated contrast
Lower osmolality contrast remains _____ when introduced ______
- Intact
- Into the blood or other body cavities
How long will it take for water-soluble contrast to outline the colon?
4 hours
What does double contrast studies employ?
- Both radiopaque and radiolucent contrast media
- Barium sulfate + Air or carbon dioxide
How do you introduce air into the body while patient is drinking barium?
Small pinholes are place in the straw
What is introduce into the body when the patient swallows gas-producing crystals?
Carbon dioxide gas
Carbon dioxide gas is introduced by ________
ingesting gas-producing crystals
What are some examples of gas-producing cyrstals?
- Calcium
- Magnesium citrate
What does the double contrast technique improve visualization of?
Stomach mucosal folds (rugae)
What contrast technique improves the visualization of stomach mucosal folds?
Double contrast
What can also be demonstrated with the double contrast technique?
- Potential polyps
- Diverticula
- Ulcers
What are the two types of injectable iodinated contrast media?
- Ionic
- Non-ionic
What does injectable contrast media contain?
Iodine
What is osmollity?
A measure of the total number of particles in a solution per kilogram of water
What is a measure of the total number of particles in a solution per kilogram of water?
Osmolality
Whats viscosity?
Resistance of fluid to movement; measured by the amount of force required to move liquid under specific condition
What is the resistance of fluid to movement; measured by the amount of force required to move liquid under specific condition called?
Viscosity
_____ the temperature of a fluid ______ its viscosity
- Increasing
- Decreases
What is a tri-iodinated molecule?
Contains 3 atoms of iodine and a cation and anion
Is a cation positively charged or negatively?
Positively
Is a anion positively charged or negatively?
Negatively
What are some examples of higher osmolality contrast?
-Hypaque
- Conray
- Renografin
What is higher-osmolality contrast?
Contrast with an increased number of particles in a solution (such as blood plasma)
Higher-osmolality contrast is associated with ________
greater chance of adverse reactions
Why is higher-osmolality contrast assosciated with an increase reaction rate?
Due to the disruption of homeostasis
Why do higher-osmolality contrast have an increased number of particles?
The cation separated from the molecule resulting in two separate ions in the blood
What kind of contrast contains no cations?
Non-ionic iodinated contrast
Non-ionic iodinated contrast contain only _____
3 atoms of iodine
Why is lower osmolality contrast associated with a decreased reaction rate?
Does not increase the osmolality of blood plasma
Why is non-ionic contrast lower osmolality?
Molecules don’t dissociate into ions
What are some contrainidicatations for injectable iodinated contrast?
- Hypersensitivity
- Anuria (anuresis)= abscence of urine
- Multiple myeloma
- diabetes (especially diabetes melitus)
- Severe hepatic or renal disease
- Congestive heart failure
- Pheochromocytoma
- Sickle cell anemia
- Patients on certain diabetic medications (i.e. metformin, glucophage, avandament)
- renal failure
What is anuria?
Absence of urine excretion
What is the absence of urine excretion called?
Anuria
How long should diabetic medication be witheld after iodnated contrast study?
48 hours
What does it mean to have a mild reaction?
Non-allergic
What does it mean to have a moderate reaction?
True allergic
What does it mean to have a severe reaction?
Vasovagal (life threatening)
What are some mild reaction to injectable iodinated contrast?
- Anxiety
- Headache
- Light-headedness
- Cough
- Nausea
- Vomiting
- Mild erythema
- Itching
- Mild, scattered hives
- Sweats
- Nasal stuffiness
What are some moderate reaction to injectable iodinated contrast?
- Urticaria (moderate to severe hives)
- Wheezing
- Dyspnea
- Dysphagia
- Bronchospasm
- Chest pain
- Tachycardia
- Bradycardia
- Hypertension
- Mild hypotension
What are some severe reaction to injectable iodinated contrast?
- Anaphylactic shock
- Profound hypotension
- Severe bradychardia
- Cardiac arrhythmia
- Laryngeal swelling
- Convulsion (seizures)
- Loss of conciousness
- Arrhthymia
- Cardiac arrest
- Respiratory arrest
- No detectable pulse
When do contrast reactions occur for injectable contrast?
First 5-10 minutes of contrast administration
When injecting iodinated contrast the patient should be _________
Closely and constantly monitored
What do mild reactions due to injected contrast require?
Observation but no treatment
What do moderate reactions due to injected contrast require?
Immediate treatment and careful observation
What do severe reactions due to injected contrast require?
Prompt recogntion, treatment, and hospitalization
Moderate reactions due to injected contrast can progress to a _______
severe reaction