An official website of the United States government
Here's how you know
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.
(a1,b1,c1,d1) are the ROIs of the original CT images marked by the red line; (a2,d2,c2,d2) are unoptimized ROI binary images; and (a3,b3,c3,d3) are optimized ROI binary images. ROI, region of interest.