Framework to generate perfusion map from CT and CTA images in patients
  with acute ischemic stroke: A longitudinal and cross-sectional study
Chayanin Tangwiriyasakul Pedro Borges Stefano Moriconi Paul Wright Yee-Haur Mah James Teo Parashkev Nachev Sebastien Ourselin M. Jorge Cardoso
Stroke is a leading cause of disability and death. Effective treatment
decisions require early and informative vascular imaging. 4D perfusion imaging
is ideal but rarely available within the first hour after stroke, whereas plain
CT and CTA usually are. Hence, we propose a framework to extract a predicted
perfusion map (PPM) derived from CT and CTA images. In all eighteen patients,
we found significantly high spatial similarity (with average Spearman's
correlation = 0.7893) between our predicted perfusion map (PPM) and the T-max
map derived from 4D-CTP. Voxelwise correlations between the PPM and National
Institutes of Health Stroke Scale (NIHSS) subscores for L/R hand motor, gaze,
and language on a large cohort of 2,110 subjects reliably mapped symptoms to
expected infarct locations. Therefore our PPM could serve as an alternative for
4D perfusion imaging, if the latter is unavailable, to investigate blood
perfusion in the first hours after hospital admission.