Q: If the initial angiogram for SAH is negative, what is the imaging algorithm?
A: Repeat the angio in 4-7 days.
The aneurysm may not be visualized because of thrombus in the dome, which may lyse, leaving the pt with the risk of rebleed.
Ddx:
Pcom aneurysm vs. infundibulum
ACR Case in Point
9/22/2014
A-comm aneurysm
https://3s.acr.org/CIP/CaseView.aspx?CaseId=3oD4kZgknt0=
An interesting story by Anton Hasso of his experience with SAH (added 8/18/22)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8334690/