Figure 3:(A) CT Perfusion source image illustrating selection of the arterial (1) and venous (2) locations for placing regions-of-interest (ROI’s), needed to construct the representative time-density curves (TDC). An additional ROI has been placed in the right MCA territory for the tissue (3) TDC.
(B) Graphic representation of the arterial (A), venous (V), and tissue (T) TDC. The TDC represents the contrast concentration in the vessel or parenchyma during a given acquisition time of the scan (Fig. 2). The x-axis reflects the time-points of the images post contrast injection during the cine acquisition (ranks). Every tick mark on the x-axis represents a 0.5 sec interval, for a total of 45 sec scan time. The y-axis reflects the contrast concentration measured in Hounsefield units (HU) at each point in time, for a given ROI.