Contrast Media

Question 1

what is contrast media

Answer 1

a compound used to enhance the contrast of a structure during medical imaging

Question 2

what does the administration of oral and IV contrast do

Answer 2

aid distinction of the GI tract and vascular structures from other tissues

Question 3

function of contrast - in the brain

Answer 3

contrast can enhance the tumour from the normal surrounding tissues in which it is located, thus improving the delineation of the gross tumour volume
this only applies to tumours of the brain

Question 4

oral administration of contrast

Answer 4

used to visualise the GI tract

barium or water soluble gastrografin

Question 5

rectally administered contrast

Answer 5

used to outline rectum

Question 6

Intravenously administered contrast

Answer 6

used to visualise tumour mass, blood vessels and urinary system

Question 6

Intravenously administered contrast

Answer 6

used to visualise tumour mass, blood vessels and urinary system

Question 7

when is IV contrast used in oncology

Answer 7

to define the treatment area for RT planning

Question 8

what are the contraindications for oral and rectal contrast

Answer 8

GI perforation
GI obstruction
Ulcerative colitis
Diverticulitis of GI tract

Question 9

what are the contraindications to IV contrast

Answer 9

previous reaction to IV contrast
impaired renal function
certain diabetes drugs (Metformin)

Question 10

how does a previous reaction to IV contrast effect the patient

Answer 10

increases the risk of a severe adverse reaction by a factor of 5

Question 11

why is impaired renal function a contraindication to IV contrast

Answer 11

IV contrast is excreted through the kidneys and can impact on kidney function

Question 12

what is used to assess patients renal function prior to administration of IV contrast

Answer 12

serum creatinine levels

Question 13

what do creatinine levels in the blood show

Answer 13

how well your kidneys are functioning

Question 14

what does estimated glomerular filtration rate (eGFR) do

Answer 14

it converts creatinine levels through a formula to an estimated rate of kidney function

Question 15

other contraindications of IV contrast

Answer 15

multiple allergies
pregnancy/lactation
potential pulmonary effects - asthma
liver failure
blood clotting disorder
multiple myeloma

Question 16

what determines the volume of the contrast and the flow rate at which it is administered?

Answer 16

a MDT consultation

Question 17

what is extravasion

Answer 17

the leakage of an intravenous drug from the vein into the surrounding tissue

Question 18

what is an air embolus

Answer 18

a blood vessel blockage caused by one or more bubbles of air or other gases in the circulatory system

Question 19

how do you prevent air embolism when administering IV contrast ?

Answer 19

ensure all air is expelled from the line prior to administration of IV contrast

Question 20

what are the side effects of contrast injection to the patient?

Answer 20

• metallic taste in the mouth
• generalised hot/warm sensation in the body
• sensation that they have passed urine

Question 21

what is the time frame for the greatest risk of reacting to IV contrast?

Answer 21

within first 5 minutes after administration