[A Mirror Image of a Tiny Distal Anterior Cerebral Artery Aneurysm that Ruptured].

Distal anterior cerebral artery(DACA)aneurysms have a low incidence. Particularly, DACA mirror aneurysms are extremely rare, although DACA multiple aneurysms are not rare. Generally, it is said that tiny aneurysms have a low risk of rupture. However, we sometimes encounter cases of ruptured tiny aneurysm. We describe a rare case of a mirror image of DACA ruptured tiny aneurysm. A tiny aneurysm can rupture if the aneurysmal wall is fragile. Detection of the aneurysm may often be difficult with a single modality, even if the modality is digital subtraction angiography. Moreover, the distribution of subarachnoid hemorrhage may not be typical. It might be important to capture a slight change of aneurysm in follow-up imaging to detect a ruptured aneurysm over multiple iterations of imaging.