Understanding Radiation Protection and Measurement Units in Medical Imaging
This article explores key concepts in radiation protection, including units of measurement for exposure, absorbed dose, and effective dose. It discusses recommended dose limits for radiologic personnel, emphasizing the importance of adhering to the ALARA principle. The text also delves into specific scenarios such as fluoroscopy, CT imaging, and the significance of personnel monitoring. By analyzing various studies and tables, the article highlights occupational exposure sources and strategies to reduce unnecessary patient doses, aiding healthcare professionals in optimizing safety protocols.
Understanding Radiation Protection and Measurement Units in Medical Imaging
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Presentation Transcript
Radiation Protection Procedures Chapters 39-40 Bushong Chapter 1 Sherer
Units of measurement • Exposure -Radiation intensity of air • What is the unit of measurement? • Dose-radiation energy absorbed from radiation exposure • What is the unit of measurement? • Effective dose-biological effectiveness of the radiation energy absorbed • What is the unit of measurement?
What is the recommended dose limit for radiologic personnel? • 50 mSv/yr • 5000mrem/yr • 5rem/yr • All of the above
The occupational dose should not normallY exceed 1 mSv/yr (100mrem/yr) • See chart 40-1 • Fluoro/portables (Exposure =exposure rate x time) • Which is better for the operator in terms of exposure in a fluoroscopy study • Tube over patient? • Tube under patient?
Personnel Exposure in • Interventional • What part of the body receives the highest dose? • Mammography • Requires minimal or no lead shielding. Why? • CT • Describe the beam in the CT room • Surgery • Interesting results from study • Mobile • Who must be “badged’?
Think of two reasons why society is interested in exposure rates to patients
ESE, GONADAL DOSE,MEAN MARROW DOSE • ESE Table 39-1 in Bushong or TABLE 1-5 in Sherer. • ESE and nomograms • Mean marrow dose…see table 39-2(Bushong) and table 1-7 in Sherer…how are they different?
Genetically Significant Dose • Estimating gonad dose = suspected genetic effects of radiation • Averages those patients who are irradiated and those who are not • Calculates the total genetic effect over a large population
DOSE IN CT IMAGING • SKIN DOSE-HIGHER • SPIRAL/MULTISLICE IMAGING –lower than conventional CT Why? • 10% OF X-RAYS ARE CT SCANS YET CT SCAN ATTRIBUTE FOR 70% OF TOTAL PATIENT EFFECTIVE DOSE • CT dose= AVE FLUORO DOSE • REDUCTION OF UNNECESSART PATIENT DOSE- PGS 604-606
REDUCING OCCUPATIONAL EXPOSURE • 95% of occupational exposure comes from? • In fluoro, an RT should • A portable the cord should be • The three types of personnel monitors are? • Describe how the radiation is calculated. • MC RT students wear?
SHERER CHAPTER 1 RADIATION PROTECTION • Diagnostic Efficacy • TDS • ALARA • ORP • BERT Values • Equivalent dose Eqd • Effective dose EfD
ShererChpt 1Manmade Radiation • Products EqD • Air Travel EqD • Nuclear fuel EqD • Fallout from Nuclear testing EqD • Nuclear Accidents • Three mile island • Chernobyl
The Ethos project • Medical Radiation
