Collateral Adequacy as a Predictor of Eventual DWI Lesion Volume in Patients with Acute Ischemic Stroke Undergoing EVT
Piyush Ojha, MBBS, MD, DM
Yu I, Bang OY, Chung J-W, Kim Y-C, Choi E-H, Seo W-K, et al. Admission Diffusion-Weighted Imaging Lesion Volume in Patients With Large Vessel Occlusion Stroke and Alberta Stroke Program Early CT Score of ≥6 Points: Serial Computed Tomography-Magnetic Resonance Imaging Collateral Measurements. Stroke. 2019;50:3115–3120.
In patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO), infarct grows over time after arterial occlusion, the progression of which may be non-linear across individuals depending on the variations in the collateral blood flow capacity and the cerebral ischemic tolerance.
The pial collateral status, which can be assessed by conventional angiography, single-phase or multiphase CT angiography (mCTA), CT perfusion, and contrast-enhanced MRI, is a key determinant of the infarct volume and progression in patients with AIS due to LVO. In addition to a small core (ASPECTS ≥6 points on NCCT), pial collateral status can be used for guiding patient selection for EVT.
Inwu Yu et al. in this study hypothesized that the pial collateral status at the time of presentation could predict the infarct size on MRI in patients with similar degrees of early ischemic changes on CT and hence tested the association between serial changes in collateral status and infarct volume defined as DWI lesions in patients with LVO and small core. They also tested whether mCTA- and MRI-based collaterals are congruent over time during the hyperacute phase of stroke.