Different scales are used to assess with techniques CT / MR perfusion and therefore the viability of the tissue to initiate proceedings and the possibility of extending the time window endovascular procedures. Mainly they were initially assessed and validated with angiography but can also be evaluated with CT angiography before the start and selection of cases for a procedure.

      Although there are very useful, the interobserver variability and technology in acquisition speed of  sequences with angio-CT in case of occluded vessels and anatomical varieties do not always get optimal results.

Press here to check an example of collaterals through Willis polygon to compensate left carotid occlusion⇐

However new softwares as RAPID (iSCHEMIA VIEW) let us to get a good evaluation of perfusion and volume map, they can aid to select patients to endovascular treatment.

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