In January 2004, the Center for Gamma-Ray Imaging (CGRI), a research resource funded by the National Institute of Biomedical Imaging and Bioengineering (NIBIB), hosted “The Workshop on Small-Animal SPECT” in Tucson, Arizona. Over 80 people from around the world attended this workshop, which included numerous short courses and contributed papers. The primary objective of the workshop was to provide education in some of the key technologies and applications that have been going on in the Center