A 57 year old woman presented with acute onset weakness of the right side of the body since five hours
Axial and coronal sections of the CT angiogram of the brain show an unruptured, well-defined, saccular outpouching approximately 5 x 5 mm with a wide neck of 4 mm arising from the M1-M2 junction of the left middle cerebral artery. There are no filling defects in the aneurysm.