Repeat non-contrast CT, CTA, and CTV done less than 90 minutes later:
The intraparenchymal hemorrhage has widened and more blood has entered the left ventricle. The occipital and temporal horns of the lateral ventricles have dilated.
There is a tiny pedunculated left pericallosal artery aneurysm that appears to grow in the venous phase, proof that it is the source of the bleed.