THE HALIFAX ACUTE STROKE IMAGING STUDY (HASIS): DOES CT PERFUSION SCANNING IN ACUTE ISCHEMIC STROKE PREDICT FINAL INFARCT VOLUME?

Introduction Study aim: to assess what computed tomography perfusion (CTP) and CT angiography source imaging (CTA SI) add to the baseline assessment of patients with suspected acute ischaemic stroke (AIS). Hypothesis: the final volume of infarcted brain will not be smaller than that predicted by the cerebral blood volume (CBV) parameter on acute CTP imaging. Methods This was a retrospective imaging study analysing imaging data of patients admitted to the Queen Elizabeth II Health Sciences Centre via the acute stroke protocol from 1st April–31st August 2012. Clinical data from the Registry of the Capital District Stroke Program (RCDSP), and CT images from the Nova Scotia Picture Archiving and Communications Systems were used. A manual tracing technique using the “Markup Freeform” tool via AGFA IMPAX version 6.5.1.1008 was used to calculate lesion volumes. The primary outcome measure was the difference in volume between the ischaemic tissue on CTP and SI at admission, with the infarct volume on follow–up CT or diffusion–weighted imaging sequences on magnetic resonance imaging (MRI). Results For full analysis, 38 patients met inclusion/exclusion criteria. There was no difference between CTP CBV or SI and follow–up MRI/CT lesion volume (P>0.05). Lesion volumes were greater on time to peak (TTP) and cerebral blood flow (CBF) CTP images compared to follow–up MRI/CT (P