CT Perfusion Mean Transit Time Maps Optimally Distinguish Benign Oligemia from True “At-Risk” Ischemic Penumbra, but Thresholds Vary by Postprocessing Technique ==================================================================================================================================================================== * Shervin Kamalian * Shahmir Kamalian * A.A. Konstas * M.B. Maas * S. Payabvash * S.R. Pomerantz * P.W. Schaefer * K.L. Furie * R.G. González * M.H. Lev