Imaging in Circulatory Disturbances

Question 1

What different imaging options are there to image the vascular system?

Answer 1

X-ray
Catheter angiography
Ultrasound
CT
MRI
Radionuclide imaging
Ultrasound

Question 2

Describe catheter angiography.

Answer 2

Vessel punctured and catharised- sterile process

Question 3

How is the catheter injected in catheter angiography?

Answer 3

Using a pump injector

Question 4

What are some of the challenges with vascular imaging?

Answer 4

Soft tissue contrast- some important vessels aren’t very visible
Functional significance of lesions- sometimes don’t mean anything

Question 5

Which important structures can it be hard to see in vascular imaging?

Answer 5

Blood vessels
Lumen of hollow viscera

Question 6

In terms of radiographic contrast, discuss the appearance of bone, air and fat.

Answer 6

Air- darkest, black
Fat- middle
Bone- brightest

Question 7

What questions are asked when looking at vascular imaging?

Answer 7

What is the anatomy?
Is there a blockage?
Is the occlusion/stenosis clinically significant?
Is there a leak?
Can it be fixed?

Question 8

What would you expect to see if there’s a clot in the patient’s right
to middle cerebral artery?

Answer 8

Left sided weakness

Question 9

What are some of the limitations of CT?

Answer 9

-Cannot identify small volume leaks
-Cannot always differentiate between acute and chronic thrombosis

Question 10

What are some of the advantages of intravenous contrast?

Answer 10

High density (iodine)
Inert
Stable in different body compartments
Painless
Cheap
Easy to use
Differential X-ray attenuation
Injected during different phases/speed using pressurised pump

Question 11

What are some problems with iodinated contrasts?

Answer 11

MAJOR ALLERGIC REACTIONS
RENAL DYSFUNCTION
DISTURBANCE OF THRYOID METABOLISM
DISTURBANCE OF CLOTTING MECHANISM
SEIZURES
PULMONARY OEDEMA
COMMON DESCRIPTIONS FROM PATIENTS:
‘FEELS LIKE MICTURITION’
WARMTH SENSATION
DISCOMFORT
NAUSEA – RARE
METALLIC TASTE

sorry it’s in caps but I cba typing it all out xox

Question 12

What are some of the considerations to be taken into account before using contrast?

Answer 12

Any allergies
Asthma
Poor renal function
Patients who take metformin

Question 13

What are some of the more common reactions to contrast?

Answer 13

Nausea
Itching
Flushing
Seizures sometimes

Question 14

What are some of the effects of an anaphylaxis reaction to contrast?

Answer 14

-Hypotension
- Pulmonary oedema
- Bronchospasm
- Seizures

Question 15

Which mode is most commonly used in ultrasound?

Answer 15

B-mode

Question 16

What does b-mode stand for?

Answer 16

Brightness mode

Question 17

What does M-mode stand for?

Answer 17

Motion mode

Question 18

What is M-mode usually used for?

Answer 18

To assess heart valve movement as well as heart chamber dimension and function

Question 19

When might a contrast be used in ultrasound?

Answer 19

Characterising lesions
Assessment of organ perfusion

Question 20

What can be used as an alternative to CT/MRI if a patient is unable to undergo those processes due to allergic reactions or claustrophobia?

Answer 20

Ultrasound

Question 21

How does the number of planes relate to the quality of an image taken?

Answer 21

More planes, better quality

Question 22

What does windowing in CT do?

Answer 22

Windowing changes the shading of pixels to make easier for human eye to appreciate particular structures

Question 23

How does CT generate images?

Answer 23

Using attenuation of radiation

Question 24

How does UTS generate images?

Answer 24

Using reflection of sound waves