MIRA2015 Lecture Notes - Lecture 2: Radioactive Decay, Nuclear Medicine, Internal Conversion

• School: Curtin University
• Department: Medical Imaging, Radiology & Radiography
• Course: MIRA2015
• Professor: Cat Kealley

Document Summary

Atom with excess nuclear energy (unstable), emit energy from nucleus (radioactive radionuclides/radioisotopes are interchangeable terms radionuclides + pharmaceuticals = radiopharmaceuticals decay) as: Conversion electron rate of decay cannot be altered, not affected by heat, magnetic or electrical fields. Nucleus is more stable following the emission, may undergo further decay. Physical half-life: time taken for amount of substance radioactivity to reach half original value. Unique time for each type of radioisotope ( s to millions of years) random event -> law of averages determines physical half-lives) Gamma rays give least biological damage ideal for detection with gamma camera sufficient range: emissions leave body to be detected. Radiation dose (msv) for common x ray examination long enough that adequate activity remains for imaging short enough not to linger in the body for days/weeks (minimise dose to patient) chemical affinity for labelling. Radiation dose (msv) for common nuclear medicine procedures. Radionuclide production: bombardment of stable elements with charged beam (cyclotron)