Qualitative comparison between DSA and mixing CBF territory maps in three representative ICAD patients. Subtitles above DSA images are formatted as View (AP or lateral): Injection site. (a) 51 y/o M: DSA reveals that the RICA cross-fills the left A1 segment territory (blue arrows, top DSA image), and that the LICA fills the left A1 segment normally (red arrow, bottom DSA image). This region of mixed perfusion in the left A1 territory can be seen on the mixing CBF territory maps (bright green clusters). (b) 64 y/o F: DSA shows that the LICA cross-fills the right A1 segment territory (blue arrow, top DSA image), and that the RICA fills the right A1 segment normally with no cross-filling on the left (red arrow, bottom DSA image). The region of mixed flow is seen on the mixing CBF territory maps (bright green clusters). Mixing between the ICAs and VBA is also seen. (c) 51 y/o M: DSA shows the basilar artery cross-filling the LICA territory (red arrow, top DSA image). The corresponding CBF territory map demonstrates mixing between the LICA and VBA territories (purple cluster). DSA (bottom two images) also shows cross-filling of the LICA territory by the RICA (blue arrow, middle DSA image), with the LICA territory also being perfused normally by the LICA (green arrow, bottom DSA image). The region of mixed flow is seen on the CBF territory maps (bright green clusters).