pharmacology unit three exam

what interaction creates the image and is characterized by absorption of the beam?

photoelectric

photoelectric interaction appears:

white

what interaction leads to tech dose and is characterized by scatter?

compton

anatomic agents cannot be visualized unless there is a ____________ in radiographic _____________ from the surrounding tissues.

difference; density

list the radiographic densities in order from least dense to most dense

air, water, fat, mineral (calcium/bone), metal

there is ________ contrast between water and fat

low

low subject contrast result in _______ density differences

few

use of contast media into the area of interest will change the absorption characteristics and alter its _________ contrast

subject

enhancing the ______ differences within the area of interest will improve visualization of details

density

what is the number one reason contrast media is used?

to enhance subject contrast

atomic areas filled by _____________ agents appear dark with an increased density

radiolucent/negative

radiolucent/negative contrast agents have a _____ atomic number

low

atomic areas filled with ___________ agents appear light with a decreased density

radiopaque/positive

radiopaque/positive contrast agents have a _______ atomic number

high

what is the most common contrast used in MRI?

gadolinium - DPTA

what is the full name for gadolinium - DPTA? (spelling counts)

gadolinium diethylenetriaminepentaacetic

double contrast studies uses:

both negative (air) and positive (barium or iodine)

barium has an atomic number of:

56

barium sulfate ____ soluble in water

is not

barium is chemically:

inert or nonreactive

barium powder has a tendency to clump and come out of suspension. this is known as:

flocculation

____________________ can be used to prevent flocculation.

sodium carbonate or sodium citrate

_____________ water absorption by the colon can result in excess fluid entering the circulatory, this is called ____________.

increased; hypervolemia

barium should not be given to patients suspected of having a ___________ colon

perforated

if barium leaks into an area of the body it shouldn’t be in, it needs to be:

surgically removed

if a patient does not drink enough _______ after their study, the barium sulfate residue within the colon can _________ and cause an _________ (with symptoms of constipation).

water; dry; obstruction

who are people that might have trouble with barium contrast?

elderly, mentally disabled, patients with hypovolemia, sedated patients

what procedure can air be used alone as a negative contrast because the upper respiratory tract structures all contain air naturally? (spelling counts)

laryngopharyngography

what kind of contrast is used in spine studies?

water soluble nonionic iodinated contrast

what is an undesirable characteristic of iodinated ionic contrast?

the anion and cation can dissociate on injection into plasma

____________ = concentration of osmotically active particles & solution

osmolarity

__________ is a measure of the total number of particles in solution per kg of water.

osmolality

most adverse reactions to contrast have been related to the _______ of the media because it determines the __________ pressure

osmolality; osomotic

the most ideal contrast would be:

low osmolar, nonionic, water soluble

nonionic iodine contrast media ______ dissociate into cations and anions.

does not

osmotic effects - water moves from an area of ______ concentration to an area of _____ concentration. this is called _____. when plasma water is displaced by contrast, water from cells move into the ______ system. this can result in ________ and blood vessel _______.

high; low; osmosis; vascular; hypervolemia; dilation

water from cells to bloodstream = _______ blood volume/pressure

increased

nonionic iodine contrast ________ the amount of reactions, but can still _____ renal function.

decreases; decrease

what people are classified as renal compromised?

elderly, diabetics, renal disease, sickle cell anemia

__________ blood urea nitrogen (BUN) and creatinine levels indicate the patient may have renal disease, and could indicate a possible _____________ renal effect

increased; contrast induced

______ reveals whether the urea nitrogen levels are higher than normal suggesting the _____________ may not be working properly

BUN; kidneys/liver

_________ are nitrogen containing waste products of metabolism excreted by the _______ filtration system. __________ blood plasma levels indicate poor filtration by the kidneys.

creatinine; kidney; high

iodine mixes with blood making arteries:

radiopaque

with nonionic contrast, kidney toxicity is not __________

reduced

radiopharmaceuticals are not a ________ agent

contrast

radiopharmaceuticals are imaged using a _________ and sees/detects where the radiopharmaceutical is.

gamma camera

positron emitters are formed in a cyclotron and have very short:

half lives

what shows functional/structural aspects of the body while still using radiation?

positron emission tomography agents

PET agents are found in what modality?

nuclear medicine

what is the biggest consideration when working with positron emission tomography agents?

increased radiation exposure due to contamination on patients, personnel, floors, tables, equipment etc.

__________ - MRI contrast agent used to diagnose disorders of the brain

omniscan

__________ - MRI contrast agent used to diagnose disorders of the liver

eovist

______________ - MRI contrast agent used for MRA/s to visualize blood vessels, organs, and other non-bony tissues

gadavist/magnevist

_______________ - MRI contrast agent with many adverse side effects: NSF, organ failure, etc.

ablavar, prohance, multihance, and dotarem

__________ - only MRI contrast agent that can be used while breastfeeding

feridex

______________ - MRI contrast agent characterized by an oral suspension used to visualize the stomach, small bowel, and large intestines

gastromark

_______________ - MRI contrast agent used to diagnose disorders of the brain and spine (CNS)

optimark

_______________ - MRI contrast agent that uses magnets/computers to create images of certain areas inside the body

teslascan

________________ is a rare/serious syndrome that involves fibrosis of skin, joints, eyes, and internal organs. it is associated with exposure to _______-based MRI contrast agents.

nephrogenic systemic fibrosis (NSF); gadolinium

T or F: Barium sulfate is absorbed through the GI wall.

F

What is the term for the concentration of osmotically active particles and solution?

osmolarity

What is the term for a negatively charged particle?

Anion

A __________________ charged particle is known as an anion, and a ____________ charged particle is known as a cation.

negatively; positvely

Why is iodine used so extensively in ROCM?

enhances contrast

When are diatrizoate solutions most often used?

suspected GI perforation; CT (to decrease artifact production)

T or F: High osmolality ROCM can cause some anticoagulation, which can result in bleeding and bruising.

T

What is the term for a heart rhythm disturbance characterized by electrical impulses without cardiac contraction?

Pulseless electrical activity

What is the term for an immediately life-threatening systemic hypersensitivity reaction?

Anaphylaxis

Radiopaque contrast media are responsible for approximately what percentage of all acute renal failure events?

10%

Which of the following can result from large amounts of barium sulfate being aspirated?

• Death

• Pneumonitis

• granulomas of lung tissue and lymph nodes

all of the above

Contrast media are used in radiographic imaging to:

enhance the subject contrast of the area of interest

Radiographic images that demonstrate few density differences define:

low subject contrast

A negative contrast agent will _________ density and is __________

increase; radiolucent

A radiopharmaceutical is a:

radioactive organ specific pharmaceutical

Contrast media that dissociate into two molecular particles are known as:

ionic agents

Hydroxyl groups on nonionic water-soluble iodinated contrast media increase:

solubility

External contamination of a short-lived diagnostic radioisotope is a problem because it might:

be misconstrued as a pathologic condition on an image

Which one of the following drugs should be discontinued 48 hours before/after administration of water-soluble iodine contrast media?

• insulin

• glucagon

• beta-blockers

• metformin

metformin

What can be done to reduce allergic-like effects for a patient who will receive water-soluble iodine contrast media?

premedicate with steroids and antihistamines

Which of the following acute reactions to contrast media usually requires no medical treatment?

• bronchospasm

• laryngeal edema

• urticaria

• seizures

urticaria