Hi gang, I've been asked if there is a web site that describes Positron Emission Tomography...... PET imaging. Here is the URL for University of British Columbia's web site for the PET group. http://www.physics.ubc.ca/~pet/ There are excellent links here to PET sites around the world. Click on What is PET? for a technical description of X Ray, CT, MRI, SPECT, and PET. Happy browsing................Murray [log in to unmask]