Mean Transit Time (MTT) - time difference betwen aterial inflow and venous outflow, normal is < 7
Cerebral Blood Flow (CBF) - volume of blood flow per unit of brain, normal is 50-60 mL/100g/min, 10-25 penumbra, <10 dead
Cerebral Blood Volume (CBV) - volume of blood per unit of brain, normal is 4-5 ml/100g
Time to Peak (TTP) - time between contrast injection and attenuaation peak.
Penumbra - increased MTT and decreased CBF with normal or increased CBV