"There are 2 important radiologic variables that must be reported to help identify those patients that should be transferred: The ASPECT score and the volume of core ischemic injury.
Calculating the core ischemic volume is done off the DWI sequence and is straight forward: multiply the AP, transverse and SI dimensions of the stroke and divide by 2 (ABC/2).
Note that this does NOT mean that all acute stroke patients should get an emergent MRI, just those who are candidates for IA therapy (high ASPECT score and clot in a large vessel as seen on CTA) and the MRI should NOT delay administration of IV tPA which can be given prior to or on the way to MR."
Pierre
Stroke protocol includes:
History
Symptoms, laterality, time last seen well
CT of the head, without intravenous contrast
Check for hemorrhage
ASPECT score:
Normal is 10,
Subtract 1 for each affected region with loss of gray-white differentiation
Less than 6 unlikely to benefit from intra-arterial therapy
CT angiography of the head and neck, with intravenous contrast
If occlusion of large vessel, patient may benefit from clot retrieval
If m1 clot do multiphase for collaterals
Recent trials demonstrate significant benefit from new clot retrieval device
MR imaging of the brain, without intravenous contrast
Calculate core ischemic volume on DWI
Multiply dimensions anteroposterior * transverse * superior-inferior, divide by two
Volume = (AP*TR*SI)/2
over 70 ml is higher risk
