ABCs of Radiation Safety Joseph D. Babb, MD FACC FSCAI Professor of Medicine East Carolina University

Conflicts of Interest None for purposes of this presentation Acknowledgements Thomas Bashore, MD FSCAI Stephen Balter, PhD FSCAI For allowing me to use some of their illustrations

Message Keep the x-ray source (the tube) as far away from you (the operator) as possible consistent with optimal imaging.

Radiation Safety Principle Use the least amount of magnification consistent with seeing the object adequately. BIGGER IS NOT ALWAYS BETTER!! A larger image means more radiation –If it is necessary for adequate visualization, fine –If it does not improve procedure safety or performance, reduce the magnification

Stochastic effects Probability proportional to dose Severity independent of dose Assumed zero threshold Risks are Radiogenic Cancer and Genetic Damage

Deterministic effects Certainty of effect Severity is a function of dose Substantial threshold High dose risks are: hair loss, skin damage, cataracts, and congenital abnormalities

Time Radiation is only produced when the beam is on! Irradiate only when it is necessary to observe motion. Last-image-hold and instant replay can usually save dose.

Distance effect Use the inverse square law to your advantage and whenever possible move away from the x-ray source as far as safety allows.

Shielding Protective shielding can markedly reduce staff risk. (when used!) Structural Shielding Mobile Shielding Personal Shielding

Protective Clothing Well tailored apron Thyroid collar Eye protection

Collimation

Wear Your Exposure Badge It is for your benefit The readings should correlate with your workload Over-lead monitor on midline at neck level Under-lead monitor on midline at waist level Weighted average for estimating stochastic risk

Summary Safe use of radiography demands understanding of basic radiation physics –Sources of radiation –Proper positioning of patient in x-ray beam –Maintenance of I.I. close as possible to patient –Proper use of shielding Use the inverse square law of radiation exposure to your advantage Use the least magnification consistent with adequate visualization Only activate the x-ray when moving a device or assessing and injection! Always wear your film badge and change monthly