Identification of Infarct Core and Penumbra in Acute Stroke Using CT Perfusion Source Images

The arterial phase CT perfusion source image (CTP-SI) and the venous phase CTP-SI are respectively obtained at the peak points of the arterial (B, red curve) and venous time attenuation curves (TACs) (B, blue curve). On the maximum-intensity-projection image (A), the region of interest is on the area of the anterior cerebral artery (A, red circle); for the arterial TAC curve (B, red curve), the region of interest is on the area of the venous sinus (A, blue circle) for the venous TAC (B, blue curve). On the TAC (B), the horizontal axis is time (seconds) and the vertical axis is attenuation (Hounsfield units). There are 40 seconds in the horizontal axis, every second corresponding to 1 image in each section. With this patient as an example, the peak point of the arterial phase is 15 seconds after scanning begins (at the peak point of the red curve, B).The arterial phase CTP-SI is the fifteenth image in each section (C, left side); the peak point of the venous phase is 23 seconds after scanning begins at the peak point of blue curve (B). The venous phase CTP-SI is the twenty-third image in each section (C, right side).