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.
Initial placement of two portals and related anatomy. (A). Skin entry points for two portals; and (B) position of two portals on an anteroposterior view of x-ray (yellow line: the site for placement of the cranial portal; red line: the site for placement of the caudal portal; dotted line: midline; white line: medial pedicular line).
