lec 5- contrast media 2

Question 1

what are 3 ways contrast media helps?

Answer 1

Enhance the contrast of the image

Can reveal the urinary structures by attenuating the x-ray beam, thereby giving the opaque appearance

Using double contrast (positive and negative) we can highlight anatomy more than just a plain x-ray can

Question 2

Would you use negative contrast in the urinary system?

Answer 2

Water can be used to fill the bladder, however, air in the ureters can mimic a stone and also cause an air embolus

Question 3

what are 5 methods of contrast administration?

Answer 3

Oral
Intra-arterial
IV
Cavity
Intrathecal

Question 4

what is the seldinger technique?

Answer 4

Used to introduce a catheter into any organ that can be accessed via needle

Question 5

What does step one of the seldinger technique involve?

Answer 5

Locate the organ/vessel to be injected/cannulated.

Question 6

What are 3 complications of step 1 of the seldinger technique?

Answer 6

1. Needle goes through organs not supposed to
2. arterial dissection
3. needle goes straight through the organ

Question 7

if a complication during the seldinger technique occurs, what do you need to do?

Answer 7

An Incident form must be filled out by relevant staff

Question 8

what does step 2 of the seldinger technique involve?

Answer 8

Once the needle has been located in the correct area/organ, insert a guide wire through the needle. The position of the wire should sit within the organ in question

Question 9

what are 3 complication of step 2 of the seldinger technique

Answer 9

1. wire goes through the organ
2. arterial dissection
3. if the wire is inserted into an artery, it can break off ‘plaque’ and cause an embolism

Question 10

what does step 3 of the seldinger technique involve?

Answer 10

Withdraw the needle, leaving the wire in place

Question 11

what is 1 complication of step 3 of the seldinger technique?

Answer 11

1. when withdrawing the needle, the wire can slip out as well

Question 12

what does step 4 of the seldinger technique involve?

Answer 12

Insert the catheter over the wire

Question 13

2 complications of step 4 of the seldinger technique

Answer 13

Can cause many complications;

1. artery may spasm
2. arterial dissection

Question 14

what does step 5 of the seldinger technique involve?

Answer 14

Withdraw the wire. Now the catheter is in place, fluids may be injected or withdrawn.

Question 15

what is the subtraction technique?

Answer 15

used to isolate the anatomy in question without any background anatomy

Question 16

what does the subtraction technique involve?

Answer 16

A pre image is taken. Then the injector pushes the contrast in and the run is acquired. The computer is then instructed (depends on the software as to how this is done) to remove the items from image 1 from image 2. The resulting image is then the subtracted image leaving the artery only

Question 17

what is the road mapping technique

Answer 17

Outline of the pathway of an “object” (usually a vessel) so that it can be displayed on a screen to guide the wire/catheter/balloon to the correct position without having to rescreen the area all the time
Cutting down on contrast exposure and radiation exposure

Question 18

what are 6 risk factors for contrast administration

Answer 18

• asthma
• anxiety
• dehydration
• general allergy disposition
• cardiac disease
• interleukin 2

Question 19

what are 9 contraindications for contrast administration

Answer 19

1. allergy to contrast
2. internal bleeding
3. renal failure
4. metformin
5. increased creatinine
6. thyroid pathology
7. hyperthyroidism
8. multi-nodule goitre
9. prior thyroid NM scan

Question 20

what are 3 ways step one of the seldinger technique can be achieved?

Answer 20

This can be done via

1: Ultrasound
2: CT
3: palpation (pulse of the artery or lump of the cyst etc.)