Abstract WMP23: Regional Assessment of Multi-phase CTA and CT Perfusion are Equivalent in Predicting Tissue Fate in Ischemic Stroke

Introduction: The use of CT Perfusion (CTP) in acute ischemic stroke (AIS) to determine patients with large ischemic core is still hampered by slow processing time, among other technical/standardization issues. Multi-phase CTA (mCTA) may be quicker and more practical in this regard. We sought to determine i) the performance of mCTA and CTP to predict regional infarction and ii) which mCTA construct(s) corresponds to which CTP parameter . Methods: mCTA and CTP was performed less than 12hrs from ictus in 77 patients with MCA-M1 occlusions. Regional analysis was performed within M2-M6 ASPECTS-regions. mCTA: regional pial vessels were assessed according to three constructs: i) Delay in maximal pial vessel enhancement compared to contralateral hemisphere; ii) Washout of contrast within pial vessels; iii) Extent of maximal pial vessel enhancement compared to contralateral hemisphere (Figure 1). CTP-CBF, CBV, MTT, IRF-T0, and Tmax values were determined. 24-hour MR-DWI or NCCT was used for final infarction. Results: There was a negligible difference in the predictive accuracy of mCTA and CTP in discriminating infarction (i.e., 84.59% and 83.04%, respectively). mCTA-Extent had the largest discriminatory power, while CTP-Tmax had the largest discriminatory power. Conclusion: Herein we show that mCTA assessments, even within small brain regions can help determine tissue fate when adjusted for recanalization, and is as good as CTP. mCTA may be a more practical modality to obtain similar prognostic information for radiological and clinical outcomes in AIS, informing acute treatment and tertiary centre triaging.