Nuclear - Radiation Safety, Radiopharmaceuticals Flashcards
What is the uniformity standard performance parameter for detectors in SPECT?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/293/767/889/a_image_thumb.png?1574009273)
Describe the findings
![](https://s3.amazonaws.com/brainscape-prod/system/cm/293/775/670/q_image_thumb.png?1574009425)
Uniformity test
![](https://s3.amazonaws.com/brainscape-prod/system/cm/293/775/670/a_image_thumb.png?1574009431)
Describe the findings
![](https://s3.amazonaws.com/brainscape-prod/system/cm/293/775/684/q_image_thumb.png?1574009478)
Cracked crystal
![](https://s3.amazonaws.com/brainscape-prod/system/cm/293/775/684/a_image_thumb.png?1574009490)
Describe how to measure change in sensitivity?
record the time taken to acquire a preset number of counts using a set dose
What is the cause of “ring artifact” on SPECT imaing?
non-uniformity on SPECT
![](https://s3.amazonaws.com/brainscape-prod/system/cm/293/776/135/a_image_thumb.png?1574009797)
How frequently should these QC measures be performed:
- COR
- Plexiglas phantom
- Uniformity correction
- COR –> weekly or monthly
- Plexiglas phantom –> quarterly or annually
- Uniformity correction –> manufacturer recommendation
What are examples of COR artifacts?
- Doughnut artifact (360 degrees)
- Tuning fork artifact (180 degrees)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/293/776/334/a_image_thumb.png?1574010082)
What is a survery meter (Geiger counter, Geiger-Mueller counter, GM counter)?
used daily to detect radioactive contamination in labs
What are QC checks that should be done on survey counters daily?
- Battery check
- Source check
- ensure meter responds to radiation
How often should survey counter calibration be performed?
annually
What are the standard testing done on dose calibrators?
- Background
- Voltage
- Accuracy
- Constancy
- Linearity
- Geometry
What are common isotopes used for annual dose calibrator accuracy testing?
- Co-57
- Cs-137
*** Results must be within 5%
****sources must be traceable to the National Institute of Standards and Technology (NIST)
What does a geometry test measure?
ability of the dose calibrator to measure accurately with consistent activity at different volumes
- performed at installation, recalibration, “plug-in”
What is a constancy test?
- designed to show that a long half-life source yields reproducible readings
- within 5% of decay corrected accuracy readings
- check each setting (isotope) button
What is a linearity test?
assesses ability to read both high and low activity (range)
- performed quarterly
What is a Rad?
- radiation absorbed dose
- energy absorbed in material
What is a Gray?
100 Rad = 1 Gray
SI unit for Radiation Absorbed Dose
Define Relative Biological Effectivenss (RBE)
- ratio of biological effectiveness of one type of ionizing radiation relative to another, given the same amount of absorbed energy
- different types of radiation have diffierent biologic burdens
How can you calculate a Roentgen Equivalent Man (Rem)?
Rem = Rad x QF
- 1 Rad gamma rays = 1 Rem
- 1 Rad alpha particles = 20 Rem
What is the international unit for Rem
Sievert (Sv)
- 100 Rem = 1 Sv
Describe the radiological units summary
- Roentgen (R)
- Rad
- Rem
- SI units
- Gray (Gy)
- Sievert (Sv)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/293/798/467/a_image_thumb.png?1574025859)
What are the Quality Factors (QF):
- XR, Gamma rays
- Beta particles
- Neutrons and Protons
- Alpha particles
- XR, Gamma rays –> 1.0
- Beta particles –> 1.0
- Neutrons and Protons –> 10
- Alpha particles –> 20
What is the international unit to express dose equivalent?
Sievert (Sv)
What are the assumptions and limitations of the Medical Internal Radiation Dose (MIRD) method?
- radioactivity is uniformly distributed in the organ
- organ size assumed for the standard person
- cellular level micro-dosimetry is not modeled
What is the effective radiation dose per examination:
- Tc99m Sestamibi
- Tl201
- Cardiac cath
- CT angio
- CXR
![](https://s3.amazonaws.com/brainscape-prod/system/cm/293/799/338/a_image_thumb.png?1574026863)
What is the dose limit:
- non-occupational dose limits from occupational sources (shielding of rooms, breastfeeding)
1 mSv (100 mRem)
What is the dose limit:
- infrequent exposure from other’s medical procedures (family member, release to public)
5 mSv (500 mRem)
What is the dose limit:
- occupational dose limits
- models determining the equivalent chance of developing major cancer = as that of a major work related event
![](https://s3.amazonaws.com/brainscape-prod/system/cm/293/801/468/a_image_thumb.png?1574027694)
What are the Quarterly ALARA Investigational Levels?
![](https://s3.amazonaws.com/brainscape-prod/system/cm/293/801/605/a_image_thumb.png?1574027814)
What steps should be taken if you reach a Quarterly ALARA investigational level?
- Level I –> Notify and action taken at RSO discretion
- Level II –> Investigate and take action
What is the natural background received by a person living the US each year?
300 mRem/year
What is the annual whole-body dose limit for an occupational worker?
5 Rem or 0.05 Sv
What is the dose limit:
- Pregnant workers
500 mRem (5 mSv) over gestation period
- < 50 mRem / month
- fetus is a non-occupational worker
What are the regulations for breastfeeding?
reduce the dose to a newborn infant to < 1 mSv (actual regulation is < 5 mSv)