THE COVER

This multi-detector positron scanner is used to locate tumors. A radioisotope-labeled substance is injected into the body and subsequently concentrates in the tumor tissue. The radioisotope emits positrons that immediately decay and produce two gamma rays that travel in opposite directions. These rays are detected simultaneously on a pair of opposing detection crystals and a line is established along which the tumor is located. This method is one of many ways doctors use radioisotopes to combat disease. In this, as in many other procedures described in this booklet, the patient remains comfortable at all times.

THE AUTHOR

Earl W. Phelan is Professor of Chemistry at Tusculum College, Greeneville, Tennessee. From 1952 to 1965, he served as Staff Assistant in the Laboratory Director’s Office at Argonne National Laboratory, where his duties included editing the Argonne Reviews and supplying information to students. For 22 years prior to moving to Argonne he served as Head of the Chemistry Department of the Valdosta State College In Georgia. He received his B.S. and Ph.D. degrees from Cornell University.