This was vaguely touched upon in several questions, but never directly assessed:
Question 13 from the first paper of 2006 (regarding brain death)
Question 2 from the first paper of 2008 (regarding the use of ultrasound in general)
Question 8 from the first paper of 2008 (regarding the diagnosis of vasospasm)
Question 5 from the first paper of 2013 (regarding the diagnosis of brain death)
Question 2 from the second paper of 2013 (again about the vasospasm)
2MHz low frequency probe on temporal bone to measure flow in MCA.
- normal flow: mean = 55cm/sec
- mild stenosis: > 120cm/sec
- moderate stenosis: > 160cm/sec
- severe stenosis: > 200cm/sec
Useful for the following:
- vasospasm post SAH
- assessment of cerebral blood flow
Non-invasive and easily repeatable.
- Vasospasm or hyperaemia can both cause increased flow velocity
- sensitivity 80% compared to angiography
- Operator dependent
- Other than ICA and MCA, unable image the other vessels
- Dependent on a good view
- Multiple confounding factors; haematocrit, blood pressure, etc.
- Not validated for use in diagnosis of brain death by ANZICS