An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
McAdams HP, Gordon DS, White CS.McAdams HP, et al.AJR Am J Roentgenol. 1996 Oct;167(4):927-30. doi: 10.2214/ajr.167.4.8819385.AJR Am J Roentgenol. 1996.PMID: 8819385