Abstract
The fourth “International Topical Meeting on Neutron Radiography” (ITMNR-4) was held from June 3–6, 2001 in the very pleasant environment of Pennsylvania's “student's city,” State College (USA). Previous conferences on neutron radiography topics took place in Canada (1992), Japan (1995) and Switzerland (1998).This series of meetings has been organized by the World Conferences on Neutron Radiography in order to have the options for a very intensive exchange of information in a regular schedule.