There is a large volume of acute subarachnoid blood within the suprasellar, ambient, interpeduncular and prepontine cisterns as well as the sylvian fissures and cerebral sulci bilaterally.
Large, amount of blood is centered upon the left sylvian fissure, with possible intraparenchymal component.
No intraventricular blood.
Grey-white matter differentiation at the left insula cortex is difficult to assess due to adjacent hyperdense blood.
Grey-white matter differentiation is preserved elsewhere.
There is a 4.8 x 9.4 mm bilobed saccular aneurysm at the bifurcation of the left MCA, with a 2 mm neck.
There is also a 4.5 x 3.6 mm saccular aneurysm at the bifurcation of the right MCA, with a 1.5 mm neck.
The rest of the intracranial arteries opacify normally.
Conventional aortic arch branching morphology.
No significant neck artery stenosis.
Bilateral MCA bifurcation aneurysms, larger on the left.
Large amount of subarachnoid blood is in keeping with aneurysm rupture, likely from the left, given most of the blood is centred there.