and
EMBASE databases, from 1985 until January 2010 and
then complemented to July 2012, using prespecified
Medical Subject Headings (MeSH) terms and key words
depicted by the task force. MeSH terms were pretested
for validity through identification of several key articles.
It was deemed unlikely that studies prior to 1985 would
be useful considering the wide-scale introduction of CT
scanning around this period. We did not apply any other
limitations to the search.