What are the Common Radiology Terminology – Lesson 02 || Shri Ram Medical College

Cosmic radiation: When heavy particles from other galaxies, made up of nuclei of all known natural elements, hit the earth from space, they release radiation. Criticality: A fission process in which the rate of making neutrons is the same as the rate of losing neutrons through absorption or leakage. Critical mass: the smallest amount of fissile material that can start a nuclear chain reaction that can keep going on its own. Cumulative dose: the total dose that happens when the same part of the body or the whole body is repeatedly or continuously exposed to ionizing radiation. Curie (Ci): the traditional unit of radioactivity based on how fast 1 gram of radium breaks down. In one second, one curie of radioactive matter will break down 37 billion times. Cutaneous Radiation Syndrome (CRS): The complicated syndrome caused by getting more than 200 rads of radiation on the skin. Decay chain (decay series): the series of changes that some radioactive elements go through before they reach a stable