Multiphase CT angiography collateral score in acute stroke
Multiphase CT angiography (mCTA) collateral score is a simple scoring system that allows quick evaluation of collateral vessel filling delay in acute ischemic stroke. In some studies, it has been shown to be a better predictor of clinical outcomes and eligibility for endovascular therapy (ECT) than a decision based on single-phase CT angiography .
mCTA collateral score
A score on a scale of 0 to 5 is given, with 5 being the mildest and 0 the most severe:
- 5: no filling delay compared to the asymptomatic contralateral hemisphere, normal pial vessels in the affected hemisphere
- 4: a filling delay of one phase in the affected hemisphere, but the extent and prominence of pial vessels is the same
- 3: a filling delay of two phases in the affected hemisphere, or a delay of one phase with a significantly reduced number of vessels in the ischemic territory
- 2: a filling delay of two phases in the affected hemisphere with a significantly reduced number of vessels in the ischemic territory, or one phase delay showing regions without visible vessels
- 1: only a few vessels are visible in the affected hemisphere in any phase
- 0: no vessels visible in the affected hemisphere in any phase
Generally, a score of 3 or less indicates a poor prognosis .