PET, CT, and MRI image files may be compressed in ZIP format (*.zip). Usually PET images are compressed to about 50% of the original size. Zip file may contain several files and sub-folders, which is practical if data is sent over internet, for example using FTP, Hermes, or Biscom.
Executable programs for Windows, and sources codes, are compressed in ZIP format. Windows and Linux computers can automatically uncompress zip files. Also freeware programs for creating zip files and uncompressing them can be downloaded from the internet: 7-zip is recommended, and it can also compress and uncompress *.7z files. For old computers http://www.info-zip.org/
PET image files contain usually small and negative pixel values outside the body. If these are removed from the image via thresholding, the compressed file may be a lot smaller. Alternatively the image areas outside of the body or regions of interests can be cut out, for example using imgslim.
Updated at: 2016-06-17
Created at: 2004-10-29
Written by: Vesa Oikonen