Abstract
This month's article has been prepared in collaboration with my colleague Dr. J. W. J. Carpender, Professor of Radiology, Director of the Chicago Tumor Institute, and Chief of the Radiation Therapy Service in the Department of Radiology at the University of Chicago. Dr. Carpender served throughout World War II as a navy radiologist and worked for a year as a graduate student in the Radiation Laboratory at the University of California; currently, he is a member and officer of numerous radiologic organizations.—Paul C. Hodges, M.D.