Hello,

Yes, the database is still available, http://miriad.drc.ion.ucl.ac.uk/

The quickest way to get all the images is to download the tarball:
1. Register and log in to the database http://miriad.drc.ion.ucl.ac.uk/atrophyc... after reading the data use agreement at http://miriad.drc.ion.ucl.ac.uk/ (accounts are manually approved, so it may take a while, you will get an email once your account is enabled).

2. then download the archive file http://miriad.drc.ion.ucl.ac.uk/atrophyc...

We've noticed the XNAT Java downloader in our version is unable to handle all the images at once, which causes some people problems. Downloading the archive file avoids that problem and gets all the images. The XNAT interface also has a very obvious "request access to this project" link for the MIRIAD project, which leads some people to think they need to additionally request access for the project after registering, this isn't necessary to gain access the project data and we usually deny such requests.

Best of luck with your research,
Ian