Week 9 Flashcards
When a nonionic contrast agent is injected into an artery…
you can visualize the artery because the iodine in the contrast agent mixes with blood and makes the artery radiopaque
A mandatory prerequisite to studies that involve contrast agents is…
taking a thorough medical history including allergies and disease
When working with a radiopharmaceutical…
the nuclear medicine professional must be aware of the half-life of the isotope, isotope leaks or spills, and contamination that yields image artifacts
Nuclear studies using radiopharmaceuticals…
are generally more functional
Define radiopharmaceuticals
Radioactive material used in nuclear medicine
T/F: nonionic low-osmolality contrast agents have gained popularity as a safer choice for iodine examinations. These still pose a risk to renal function.
True
A thorough medical history must be taken when using
contrast for a radiology exam
Patients who have compromised kidney function include what type of patients?
Patients with renal disease or diabetes and older patients
What do the lab tests BUN and Creatinine determine?
Renal disease or renal function
After contrast injection…
closely monitor the patient and look for worsening signs such as vomiting and bronchospasm and inform the Radiologist or physician
The osmotic effects of ionic contrast agents that are a result of the movement of?
Water from body cells moves into the bloodstream causing increased blood volume and higher blood pressure.
The ideal iodinated contrast agents would have…
low osmolality, nonionic chemical structure, water solubility, and 3 or more iodine atoms per molecule
Nonionic iodine contrast agents differ from ionic agents in that…
nonionic do not break down into a cation and an anion
An undesirable characteristic of ionic contrast agent is…
their dissociation into a cation and an anion when dissolved in plasma
Most adverse reactions to ionic, iodinated contrast agents are created by?
Osmotic effects
Stomach examinations using barium sulfate have some degree of risk for patients who are?
Sedated
Mentally disabled
Potentially hypovolemic
If you suspect a duodenal bulb perforation, you do not want to use what?
Barium-sulfate
Barium: atomic number (Z) is _______. It is…
56, chemically inert, and is often mixed with water and sodium citrate to prevent flocculation
Double contrast studies, air, and radiopaque contrast…
are used to pair to outline mucosal lining, joint interspaces, and passageways
Gadolinium-DTPA is used mostly in what modality?
MRI
Positive contrast agents…
have high atomic numbers, appear opaque on X-rays, and absorb X-ray photon energy to a great extent
Positive contrast agents have _____ atomic numbers while negative contrast agents have ____ atomic numbers.
Positive = high, Negative = low
There are 5 densities seen on radiographs: air/gas, water, fat, mineral, and metal. The lowest subject contrast between these five densities is between ______ and ______.
water and fat
Contrast agents can be generally classified as ____ and _____.
Radiolucent (negative), Radiopaque (positive)
