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 Justification is the answer.  Dose limits are not applicable only recommened.

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Presentation on theme: " Justification is the answer.  Dose limits are not applicable only recommened."— Presentation transcript:

1  Justification is the answer.  Dose limits are not applicable only recommened.

2 While caring for his spouse Mr. Joseph got exposed to 2 mSv. As a member of the public with 1 mSv dose limit, he can not get any radiation dose this year. Class Activity 4

3  The average dose limit for a member of the public should not exceed 1 m Sv/y over 5y.

4  Regulations require that workers occupationally exposed to ionizing radiation wear devices called dosimeters so that accumulated doses can be monitored over a period of time.  There are several types but commonly used are Thermoluminescent dosimeters (TLDs)

5  Is necessary to measure the radiation doses received by the radiation workers in the course of their work to verify that these doses are within the recommended limits.  The medical physicist, RSO will identify individuals who have higher does and counsel them before their neglectfulness reaches serious proportions.  Methods of personal monitoring: film badges, TLD, pocket dosimeters.

6 Film Thermoluminescence dosemeters (TLD) ”electronic” dosemeters Different types of personal dosemeters for monitoring external exposure

7 Applications in Nuclear medicine personal dosemeters (body, fingers…) special measurements TLDs

8 whole body extremity

9  Device used to measure and record the exposure of individuals to ionizing radiation outside the body (external dose).  Compared to photographic film dosimeters (film badges), TLD’s are more sensitive, reusable, often more nearly tissue-equivalent, cover a wider range of doses, allows us to measure deep and shallow doses, and most TLD materials are less subject to fading

10  Several types of TLD depending on the type of radiation and energies and the nature of work of the users.  Types: Whole Body (Personal), Environmental, Neutron Extremity Dosimeters.

11  Persons who are routinely exposed to radiation should wear (monitoring device).  Occasionally exposed workers need not to be monitored but removed from the exposure area/lead aprons when required.  Health care members who assist patients with radiographic procedures should be rotated.

12  TLD badge should be worn at the level of the waist or at the collar/neck region UNLESS pregnant.  Pregnant radiation workers should wear 2 TLD’s one on each location.  Radiologists/ Radiographers rarely wear ring badges; most often, they are worn by nuclear medicine technologists because of their exposure from handling radioisotopes.

13 Bench top shield Vial shields Syringe shields

14 Factors affecting the design: radionuclide activity shielding material

15 Personal (effective dose, extremity dose & contamination) Workplace (external dose rate & contamination)

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17 Any material that exhibits measurable radiation related changes can be used as detector for ionising radiation. Change of colours Chemical changes Emission of visible light Electric charge Active detectors: immediate measurement of the change. Passive detectors: processing before reading.

18 18 Safety equipment Shields Protective clothing Tools for remote handling of radioactive material Containers for radioactive waste Dose rate monitor with alarm Contamination monitor Decontamination kit Signs, labels and records

19 Part 4. Design19 FORCEPS AND TONGS

20 Signs, labels and records Activity:4312 MBq Volume:12 ml Activity concentration; 359 MBq/ml Date: 2001-10-18 Time: 07.45 Signature:SC Tc99m-MDPDateTimeActivityVolumeSignature Oct 15 07.30 22572 MBq 15 ml SC Tc.generator no: A2376 Reference activity: 30 GBq Reference date: Oct 12 12.00 GMT

21 White-I Label < 5.0  Sv/h @ surface < 0.05  Sv/h @ 1.0 m

22 Yellow-II Label 5  Sv/h @ surface < 10  Sv/h @ 1.0 m

23 Yellow-III Label > 500  Sv/h,< 2000  Sv/h @ surface > 10  Sv/h, < 100  Sv/h @ 1.0m

24 My resident doctor has got 12 mSv in her last badge report as she was wearing the badge while getting her barium study. She wants off from radiation work. ?????

25  What is medical physics: The application of physics to medicine. It generally concerns physics as applied to medical imaging and radiotherapy, although a medical physicist may also work in many other areas of healthcare.

26  Responsible for equipment performance (Quality Assurance Program) to maintain optimal diagnostic imaging quality with minimum radiation hazard to the patient and workers.  Maintain and develop quality control tests that would detect changes in imaging systems’ function and keep measurable records of all parameters.  Involved in technical specification writing and acceptance testing of new equipment acquired.  Establish and maintain a radiation safety program within the department.

27  Supervise the preparation and handling, disposal of radionuclide.  Take part in monitoring, record keeping of staff exposure levels and insure all occupational radiation exposures are monitored.  Interact with vendors of medical equipment regarding safety concerns of the department’s imagines systems.  Review and implement all policies and procedures related to radiation safety.  Involved in training and awareness of hospital staff concerning radiation safety and radioactive waste.

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30  As done before please answer the following MCQs.

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32  Via Email: Mawya@hotmail.comMawya@hotmail.com  In-person: basement next to the MRI.  For lectures and previous exams check my web page: www.kau.edu.sa/mkhafaji


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