Fig 1. Postgadolinium T1-weighted (A) and T2-weighted (B) MR images show a large, partially thrombosed aneurysm. The aneurysm contains a persistent vascular channel, which causes a ghost artifact and enhances on the postgadolinium T1-weighted image (arrows). The vascular channel is surrounded by thrombus. Note the associated mass effect on the left lateral ventricle and midline shift.