<qa>  What is the name of the brain imaging technique performed before intervention?Sophisticated brain imaging techniques will be performed before intervention i.e. standard CT scan, within 24 hours after intervention i.e. positron emission tomography, and on day 3 and on day 10 after cardiac arrest i.e. various proton magnetic resonance imaging techniques to identify ischemic burden, injured tissue and deranged energy metabolism in the brain. 