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.
Dynamic Contrast US. (a) Irregular structure. Note the twisted blood vessel (arrow). (b) Regular structure. Note the smooth, regular blood vessel (arrow). (c) Diameter of the vessel (arrow) is >2 mm. (d) Diameter of the vessels (arrows) is <2 mm. Courtesy of Onji, et al. 51
