![PDF extract preview](https://www.ajnr.org/content/early/2007/09/26/ajnr.A0724.extract.jpg)
This is a PDF-only article. The first page of the PDF of this article appears above.
This is a PDF-only article. The first page of the PDF of this article appears above.
This article has been cited by the following articles in journals that are participating in Crossref Cited-by Linking.