Week 5- Radiation Monitoring Flashcards
What is personnel dosimetry?
The monitoring of equivalent dose to any person occupationally exposed on a regular basis to ionizing radiation
What is one purpose of personnel dosimetry?
Ensures that occupational radiation exposure levels are kept well below annual effective (EfD) limits
When is personnel monitoring required?
Whenever radiation workers are likely to risk receiving 10% of the annual occupational Efd limit in a single year as a consequence of their work
What is 10% of the annual occupational EfD limit?
50 mSv (5 rem)
When do most healthcare facilities issue personnel dosimetry devices?
When personnel could receive 1% of annual EfD limit in any month
What is 1% of annual occupational EfD limit per month?
.5 mSv (50 mrem)
What is the first purpose of personnel dosimeters?
To provide an indication of the working habits/conditions of diagnostic imaging personnel
What is the second purpose of personnel dosimeters?
Determines occupational exposure by detecting and measuring the quantity of ionizing radiation to which the dosimeter has been exposed
What is a common misconception of personnel dosimeters?
Does not protect the wearer from exposure, it is only capable of detecting and measuring ionization
During routing radiographic procedures where should a dosimeter be worn?
Primary personnel dosimeter should be attached to the clothing on the front of the body at collar level
When a protective apron is used where should a dosimeter be worn?
Should be work outside the apron at collar level on the anterior surface of the body
What is the primary dosimeter measuring when its placed at collar level?
Measuring the dose to the thyroid, head and neck
When wearing an apron where should a secondary dosimeter be placed?
Under the apron at waist level
For pregnant personnel, where should the dosimeter be worn?
- Primary dosimeter worn at collar level
- Secondary dosimeter work at abdominal level
What is a type of extremity dosimeter?
A thermoluminescent dosimeter (TLD) ring badge
What is the necessity of a TLD ring?
A second monitor that should be worn when the performing radiographic procedures that require hands to be near primary x-ray beam
What does the laser etched cover of the TLD ring contain?
Personal identification
What record should radiation exposure be a part of?
Part of the employment record of all workers
What values are represented in the employment record?
Values represent the average annual EfD to the whole body
What are characteristics of personnel dosimeters?
- Lightweight and easy to carry
- Made of materials durable enough to tolerate normal daily use
- Able to detect and record both small and large exposures in a consistent manner
- Unaffected by outside influences like weather or humidity
- Are reasonably inexpensive to purchase and maintain
- Permit healthcare facilities to use large numbers of monitors in a cost-effective manner
What are the three most current types personnel dosimeters?
- Optically stimulated luminescence dosimeter (OSL)
- Direct Ion Storage (DIS)
- Extremity dosimeter (TLD)
What is the most common device used for monitoring occupational exposure?
Optically stimulated luminescence dosimeter (OSL)
What does an OSL dosimeter contain?
Aluminum oxide detector
What energy discrimination does an OSL dosimeter contain?
Filters made of aluminum, tin and copper