Cardiovascular imaging Flashcards
Which types of imaging have no radiation?
MRI and US
What are the advantages and disadvantages of a CXR?
\+Easy to do \+ Immediately available \+ Answers immediately - Radiation -Non specific
How large should the heart be on a CXR?
1/3rd of the chest diameter
Cardiothoracic ratio
How can you see cardiomegaly on a CXR?
When the heart occupies more than 50% of the thoracic diameter of a PA CXR
What are the advantages and disadvantages of catheter angiography?
\+ Excellent coronary artery depiction \+ Easily access abnormalities \+ Assess conorony plaques and stenosis \+ Assess stents and CABG - Radiation - Invasive- femoral/radial artery - Complications /bleeding - Contrast allergy/nephropathy`
What is an angioplasty?
Stretching the artery with a balloon
What are the advantages and disadvantages of an echocardiogram?
+ immediately available
+ Immediate assessment of function of the heart
+ Structural (valvular and chamber abnormalities
+ No radiation and can be repeated
- Operator dependent- requires lots of skill
- Patient dependent- difficult in obese patients
- Limited views => incomplete cardiac assessment
What are the advantages and disadvantages of a Cardiac CT +/- IV contrast?
+ Excellent coronary artery depiction
+ Non invasive coronary artery assessment
+ Functional assessment. Can estimate EDV/ESV
+ Chamber assessment
+ Look at the great vessels and lungs
- High radiation dose
- Resolution less than catheter angiography
- Potential for contrast allergy/nephropathy
- Need specialist CT equipment and expertese
Do you need contrast to see Ca++ deposits on a Cardiac CT?
No
Do you need contrast to see stenosis of the coronary arteries deposits on a Cardiac CT?
Yes- iodine contrast is used
What are the advantages and disadvantages of cardiac MRI?
+ No radiation or contrast and can easily repeat
+ Excellent soft tissue resolution (better then CT)
+ Good anatomical assessment
+ Gold standard for structure and function
- Long imaging times
- Claustrophobia
- MRI contraindications (Pacemaker, hip replacement etc)
- Specialist equipment and expertese
- Not good for looking at coronary arteries
What is an Enhancement MRI scan used for?
Looking for foci or potential foci of arrythmias
What are the 3 standard projections for cardiac MRI?
4 chamber view, 2 chamber view and Short axis (cross section through the ventricles)
What can be calculated from MRI?
Cardiac functions (LV muscle mass, EDV, ESV, and ejection fraction)
What is a Cine cardiac MRI?
4 chamber view giving a dynamic assessment of flow and turbulence. You can use other views. Video.
Most of the time, contrast is not required in MRI but what can be used?
Gadolinium contrast is used
What are the functions of nuclear cardiology?
Assess the perfusion of the myocardium
What is an isotope myocardial perfusion?
Checking the uptake of a radioactive isotope and stressed using adenosine or dipyridine (vasodilators)
Which projections are used in nuclear cardiology?
3 standard projections
What is nuclear cardiology used for in practice?
Determining the impact of coronary artery disease on regional myocardial perfusion. Helps to direct surgical or medical management
What scan can accurately calculate the ventricular ejection fraction?
Marga scan
