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.
Geographic variability in utilization of CT as the first imaging study for children with nephrolithiasis in the United States from 2003 to 2011. Census divisions are outlined by thick dark lines. NA, not applicable due to low prevalence of kidney stones.
