Figure 1: Persistent primitive olfactory artery (PPOA) as a side branch of the precommunicating part (A1) of the right anterior cerebral artery (ACA). It originates at the level of proximal end of the A1 fenestration (a) and courses to the medial surface of the frontal lobe (b). Cerebral part (C4) of the right internal carotid artery (1); left C4 (2); right A1 (3); A1 fenestration (*); right PPOA (4); right recurrent artery of Heubner (RAH) (5)); anterior communicating artery (ACoA) (6)); left A1 (7); left RAH (8); right postcommunicating part (A2) of the ACA (9); median artery of the corpus callosum (10); left A2 (11); left medial frontoorbital artery (12).