Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
MIP (left column) and axial source images at the level of C2 in supine (top row) and sitting positions (bottom row) in a healthy volunteer. In the supine position, there is a high-grade stricture of the left IJV. The EJV, NV, and VP are visible. In the sitting position, only the right IJV is visible, but narrowed. The VP are prominent, and the NV can be identified.
