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Fig 1. A, Anteroposterior view with 15° caudal angulation of the left carotid arterial phase shows clearly the origin of the saccular aneurysm (arrowhead) from the left A1 segment. Note the filling of AComA (arrow) and right A2 segment (solid arrow). B, Left anterior oblique view of the left carotid arterial phase shows the medially directed saccular aneurysm (arrowhead) and the anomalous CMA (arrow). C, Same view as in Fig 1B with a mask from the late arterial frames shows the relationship of the saccular aneurysm and the anomalous CMA clearly. The superior course of the anomalous cortical artery (arrows) and the 3 branches (arrowheads) arising from it are seen. D, Lateral view of the left carotid arterial phase shows the pericallosal artery (open arrow). Note the absent CMA from the pericallosal artery. The superiorly coursing segment of the anomalous cortical artery can be visualized anteriorly (arrow). E, Lateral view of the left carotid late arterial phase shows the saccular aneurysm (open arrow) directed anteriorly. Note the anomalous cortical artery (arrows) initially coursing below the aneurysm, then ascending in front of it, and coursing all the way up to the level of coronal suture (solid arrow). F, Magnified lateral view of the left carotid late arterial phase clearly shows the parallel course of the anomalous CMA (arrow) to the pericallosal artery (open arrow).
