Contrast Media

Question 1

What are the types of contrast media?

Answer 1

Positive and negative

Question 2

What are types of positive contrast media (administration)?

Answer 2

Oral or IV

Question 3

What are examples of positive contrast media?

Answer 3

1. Iodine
2. Barium

Question 4

How do positive contrast media appear radiographically?

Answer 4

High density and white

Question 5

What are types of negative contrast media (administration)?

Answer 5

CO2 or room air (rectal) or gas crystal

Question 6

How does negative contrast media appear radiographically?

Answer 6

Low density and black

Question 7

What is osmolality?

Answer 7

Number of particles in a solution per unit liquid

Question 8

What is viscosity?

Answer 8

Thickness or friction of the fluid as it flows

Question 9

What is iconicity?

Answer 9

Whether a solution contains molecules that form ions or not (aka ionic or non ionic)

Question 10

What is clearance?

Answer 10

The body distributing and excreting the iodinated contrast through the kidneys

Question 11

The body excretes contrast nearly exclusively by the kidneys via . . .

Answer 11

Glomerular filtration

Question 12

What is the half life of contrast in a patient with normal renal function?

Answer 12

2 hours

Question 13

What do LOCM and HOCM stand for?

Answer 13

LOCM = Low Osmolality Contrast Media
HOCM = High Osmolality Contrast Media

Question 14

What type of IVs are used for venous access?

Answer 14

Indwelling catheter or CVC (if there is one)

Question 15

What is the best vein to use for venous access?

Answer 15

Median cubital

Question 16

What may need to be changed if a small vein is used to contrast?

Answer 16

Injection rate

Question 17

What medical history may be gathered during pre injection interviews (aka contraindication)?

Answer 17

1. Allergies
2. Asthma
3. Renal function
4. Thyroid disease
5. Pregnancy
6. Diabetic (on metformin)

Question 18

What lab work must be gathered and considered before contrast administration?

Answer 18

Creatinine and GFR

Question 19

What basic information must be gathered during patient preparation(4)?

Answer 19

1. Medical history
2. Lab work
3. Patient educating about exam and informed consent
4. Documentation

Question 20

What type of contrast can cause adverse reactions?

Answer 20

Iodinated contrast

Question 21

What are the types of contrast adverse reactions(3)?

Answer 21

1. Mild
2. Moderate
3. Severe

Question 22

What are symptoms of a mild adverse reaction?

Answer 22

Cough, itching, hives, eye swelling, nasal congestion

Question 23

What is the treatment for mild adverse reactions?

Answer 23

Over the counter antihistamines (ex: Benadryl)

Question 24

What is the role of the tech during mild adverse reactions?

Answer 24

Monitor the patient and tell radiologist

Question 25

What are symptoms of moderate adverse reactions?

Answer 25

Respiratory difficulty, pulse change, hyper or hypotension

Question 26

What is the treatment for moderate adverse reactions?

Answer 26

IV Benadryl

Question 27

What is the role of the tech for moderate adverse reactions?

Answer 27

Assess vitals, inform rad *maintain IV access in case drug admin is required or out one back in!

Question 28

What are symptoms of a severe adverse reaction?

Answer 28

Substantial respiratory distress, unresponsive, convulsions, cardiac arrest

Question 29

What is the treatment of a severe adverse reaction?

Answer 29

CPR or oxygen or something

Question 30

What is the role of the tech in a severe adverse reaction?

Answer 30

Call a code blue and alert the rad, be an extra set of hands but get out of the way

Question 31

What do you do if a patient has had a previous contrast allergic reaction?

Answer 31

1. Change the contrast agent (omnipaque or isovue) 2. Premeditate the patient

Question 32

How do you pre medicate the patient before an exam with a contrast allergy?

Answer 32

13 hrs before appt: 50mg or prednisone 7 hrs before appt: 50mg or prednisone 1 hr before appt: 50mg of prednisone + 50mg diphenhydramine/20mg cetirizine

Question 33

What causes chemotoxic reactions?

Answer 33

Physicochemical properties of contrast media, dose, and speed of injection

Question 34

What might happen if metformin is taken during exam and kidney function changes?

Answer 34

May cause lactic acidosis

Question 35

What might happen if metformin is taken during exam and kidney function changes?

Answer 35

May cause lactic acidosis

Question 36

What is CIN?

Answer 36

Contrast Induced Nephropathy Toxicity to kidneys due to acute increases in SeCr

Question 37

What is extravasation?

Answer 37

Leakage of blood or other fluid (i.e. contrast) into surrounding tissue causing inflammation

Question 38

Ways to avoid extravasation

Answer 38

1. Indwelling catheter with flexible cannula (18 to 20 gauge) 2. Monitor injection site 3. Keep contrast media warm 4. Use LOCM

Question 39

How do you treat extravasation?

Answer 39

1. Stop injecting 2. Notify rad 3. Elevate + apply ice pack

Question 40

What are complications of extravasation?

Answer 40

Ulceration, necrosis, compartment syndrome

Question 41

What are the three phases of tissue enhancement?

Answer 41

1. Bolus/arterial phase 2. Non equilibrium phase 3. Equilibrium phase

Question 42

Bolus phase

Answer 42

Starts: ~20 sec after injection Contrast starts in peripheral vein, through mediastinum, to and out of the aorta (appear bright) *cortex of kidney enhanced

Question 43

Nonequilibrium phase

Answer 43

Starts: ~60 to 80 sec after injection Venous structures now appear opacified, liver parenchyma bright as well Homogenous kidney enhancement (in tubules now)

Question 44

Equilibrium phase

Answer 44

Starts: 2 min after Bolus phase Highlights organ parenchyma, not vascular structures enhanced Kidneys no longer enhanced

Question 45

What factors affect enhancement quality?

Answer 45

1. Patient weight 2. Cardiac output 3. Scan speed (delay increases = duration decreases)