CONTRAST AGENTS Flashcards
“Contrast media”
• Substances that have a higher or lower atomic number
• Taken orally or injected intravenously
CONTRAST AGENTS
Categories of Contrast media
iodine based
barium based
negative contrast
Dense chemical that is taken orally or intravenously.
IODINE BASED
2 types of iodine based
• IONIC CM
• NON-IONIC CM
Electrically negative charge acids containing iodine that ionize in solution and cause more patient discomfort.
IONIC CONTRAST MEDIA
Does NOT ionize in solution and is safer, less painful, and better tolerated by the patient
NON-IONIC CONTRAST MEDIA
A contrast medium in the radiography of the digestive tract because adverse effect it on has no the body and because of its high atomic number of 56.
BARIUM BASED
• Having a lower atomic number than the surrounding tissues and appear black on the radiograph.
• Air, carbon dioxide, & oxygen
NEGATIVE CONTRAST
IMPORTANT FACTORS IN SELECTING CONTRAST MEDIUM:
• It must be non-toxic and must be safe
• It must produce adequate contrast
• It must have a suitable viscosity
• It must have a suitable persistence
Method of introducing sensitivity testing
scleral method
sublingual
intradermal method
intravenous method
One drop of CM is put into the sclera of the eye.
SCLERAL METHOD
One drop of CM is deposited into the inferior base of the tongue
sublingual method
Icc of CM is injected just beneath the skin
intradermal method
Icc of CM is injected just into the vein
intravenous method
beam attenuation characteristics
radiolucent contrast agents (negative)
radiolucent contrast agents (positive)
medical history
allergies
treatment and occupation
time of the day
route of administration
• Produce areas of increased radiodensity
• Images appear DARK / BLACK
• They include air, gas-producing tablets. or soda water (CO2).
RADIOLUCENT CONTRAST AGENTS (NEGATIVE)
• HIGH atomic numbers
• Produce areas of decreased radiodensity
• Images appear light/white
• Include barium sulfate (BaSO4), as well as water-soluble and oil-based iodinated contrast media
RADIOLUCENT CONTRAST AGENTS (POSITIVE)
• Influences drug dosage
• People who take drugs frequently and in large quantities are less sensitive to them than those who rarely or never use them
MEDICAL HISTORY
may range from mild hypersensitivity to severe, life-threatening anaphylactic shock and may result from any anti-infective drug.
Allergies
A person’s temperament and occupation may also influences his reaction
TREATMENT & OCCCUPATION
A drug given in the morning when a patient is well rested may not be as effective as it might be later in the day.
TIME OF THE DAY
• Intravenous drug are immediately absorbed into the blood stream and circulated to all parts of the body
• Oral drugs are absorbed more slowly
ROUTE OF ADMINISTRATION
The blood vessel walls consist of three relatively distinct tissue layers:
I. TUNICA INTIMA
2. TUNICA MEDIA
3. TUNICA ADVENTITIA
Most internal layer of a blood vessel wall.
TUNICA INTIMA
Consists of smooth muscle cells arranged circularly around the blood vessel
TUNICA MEDIA
Smooth muscle contraction and causes a decrease in blood vessel diameter
VASOCONSTRICTION
Smooth muscle relaxation and causes an increase in blood vessel diameter
VASODILATION
Composed of connective tissue, which varies from dense connective tissue near the tunica media
TUNICA ADVENTITIA
carry blood away. from the heart
ARTERIES
types of arteries
elastic arteries
arterioles
“Conducting arteries”
• Have the largest diameters
• First to receive blood from the heart, blood pressure is relatively high in the elastic arteries
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ELASTIC ARTERIES
• Include medium-sized and small arteries
• The walls of some muscular arteries are relatively thick,
• Smallest arteries
• Transport blood from arteries to capillaries small
• 40 µm in diameter
• Capable of vasoconstriction and vasodilation
arterioles
carry deoxygenated blood back to the heart
VEINS
VEINS OF THE FINGERS & HAND
digital vein
dorso metacarpal vein
Flow along the lateral portion of the fingers
digital vein
Formed by the union of the digital veins
dorsometacarpal vein
veins of the arm
cephalic vein
accessory cephalic vein
basilic vein
medial antebrachial vein
median basilic vein
medial cephalic vein
upper cephalic vein
upper basilic vein
Commences at the dorsal venous arch traveling upward along the radial border of the forearm
cephalic vein
Originates from either a plexus on the back of the forearm or the dorsal venous network
accessory cephalic vein
Commences at the dorsal venous arch traveling upward along the ulnar border of the forearm.
basilic vein
Commences in the venous plexus of the palm
medial antebrachial vein
• Located on the innermost aspect of the antecubital fossa on the ulnar side
• Reserved for blood draws, peripheral midline catheters, and PICC placement
median basilic vein
• Located in the mid-antecubital fossa or inner elbow area
• Used for drawing blood
medial cephalic vein
• Located fossa above the antecubital
6mm diameter
upper cephalic vein
• Located above the antecubital fossa
• Medial to the biceps and connects to the axillary vein in the armpit area
8mm diameter
upper basilic vein
LOCATION OF BEST INSERTION SITE
antecubital fossa or the forearms.
