Cardiac Nuclear Imaging (CT & MRI)

Question 1

What are uses of cardiac nuclear imaging?

Answer 1

• Detect MI
• Measure myocardial function/ perfusion/ viability

Question 2

What radiotracers can be injected IV in nuclear imaging?

Outline their uses

Answer 2

• Thallium-201
  
  • Cardiac myopcytes take up
  • Ischaemic area (produced by exercising) with reduced tracer uptake are seen as ‘cold sports’ when imaged with a y camera
• Technetium-99m
  
  • Label RBC’s
  • Poduced images of LV during systole/ diastole

Question 3

Outline the uses of cardiac CT

Answer 3

Assess;

• Thoracic aorta & mediastinum
• Multidetector & Electron Beam CT
  
  • ​Assess calcium content of coronary arteries
  • Indicates presence/ severity of stenoses
• CT Angiography
  
  • Detection of CAD

Question 4

How do you determine the Coronary Calcium Score

Answer 4

CORONARY ARTERY CALCIUM SCORE (CACS) via Multidetector or Electron Beam CT;

• 0 - negative test, obstructed atherosclerosis highly unlikely
• >100 - High Ca score, above-avg risk of cardiac event in the following 5 years
• >1000 - Very high Ca score, high risk of cardiac event

Question 5

Outline the uses of cardiac MRI

Answer 5

• Non-invasive non-radiation imaging both anatomical and functional information

Question 6

Outline the contraindications for cardiac MRI

Answer 6

• Pacemaker/ defibrilator
• Intracerebral lips
• Significant claustrophobia

NOT coronary stents and prosthetic valves