Imaging of Circulatory Disturbances

Question 1

What are the modes of anatomical vascular imaging?

Answer 1

Plain films
Ultrasound
CT
MRI 
Contrast angiography

Question 2

What are the modes of functional vascular imaging?

Answer 2

Radionuclide imaging
MRI functional imaging
Ultrasound

Question 3

What are the problems associated with vascular imaging?

Answer 3

Soft tissue contrast
Functional significance of lesion
Determining if treatment is effective
Blood vessels and lumen of hollow viscera not seen very well

Question 4

What are the ideal properties of a man-made contrast agent in radiology?

Answer 4

Attenuation the same as the surrounding tissues
Not expensive
Inert
Equal distribution in and out of selected body compartments
Painless
Easy to use

Question 5

What are the properties of iodinated contrast?

Answer 5

Differential x-ray attenuation
Inert
Stable in selected body compartments
Painless
Easy to use
Cheap

Question 6

What are the potential problems with iodinated contrast?

Answer 6

Major reactions
Renal dysfunction
Disturbance of thyroid metabolism
Disturbance of clotting 
Seizures
Pulmonary oedema

Question 7

What are the potential properties of parenteral iodinated contrast?

Answer 7

Metallic taste
Feeling of warmth when injected
Arterial injections may cause micturition or discomfort
Can rarely cause nausea

Question 8

What needs to be discussed prior to parenteral iodinated contrast use?

Answer 8

Previous contrast allergy
Asthma or atopy
Poor renal function
Metformin use - will need to be stopped before contrast injection

Question 9

How is catheter angiography carried out?

Answer 9

Vessel punctured and catheterised
Sterile procedure
Contrast injected using pump injector
Rapid series of images acquired

Question 10

What are the uses of interventional radiology?

Answer 10

Angiography/angioplasty 
Embolisation
Catheter thrombolysis
Drainage of abscess
Nephrostomy
Vertebroplasty

Question 11

When should angioplasty be used?

Answer 11

In stenosis or occlusions

Sessile/concentric plaques

Question 12

What are the advantages and disadvantages of angioplasty?

Answer 12

Not as long lasting as surgery but not as dangerous

Question 13

How can carbon dioxide be used in radiology?

Answer 13

Negative contrast agents

Useful in patients with poor renal function or sensitivity to iodinated contrast agents

Question 14

What are the potential problems with angioplasty?

Answer 14

Occlusion
Dissection 
Embolisation
Rupture
Infection

Question 15

What are the properties of ultrasound scanning?

Answer 15

No radiation dose
Quick
Non-invasive
Resolution vs penetration 
May be more physiological
Operator dependent

Question 16

When can radionuclide imaging be used for vascular disturbances?

Answer 16

Perfusion and blood loss
Sequential imaging
Lung scintigraphy 
V/Q scan 
Perfusion of transplant kidneys
Blood loss into GI tract

Question 17

What are the properties of nuclear medicine?

Answer 17

IV injection only 
Good patient compliance
Easy to arrange 
Radiation dose
Very insensitive
Very non-specific

Question 18

What are the properties of CT angiogram?

Answer 18

Gives information about other structures
Sensitive
IV injection only 
Radiation dose
High contrast dose
Expensive

Question 19

What are the properties of MRI angiography?

Answer 19

Sensitive 
Specific
No radiation dose
No nephrotoxic contrast
Very expensive
Needs state of the art machinery 
High contrast dose

Question 20

What is involved in consenting a patient in radiology?

Answer 20

Patient learns key facts about an investigation/treatment, including potential risks and benefits, before deciding whether or not to proceed
Consent should be sought by the person doing the procedure in complex interventional radiology