Justification is the answer. Dose limits are not applicable only

recommened.

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

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

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)

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.

•Film

•Thermoluminescence dosemeters (TLD)

•”electronic” dosemeters

•Applications in Nuclear medicine

•personal dosemeters (body, fingers…)

•special measurements

whole body extremity

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

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.

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.

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.

Bench top shieldVial shields

Syringe shields

Factors affecting the design:

•radionuclide•activity•shielding material

Personal(effective dose, extremity dose & contamination)

Workplace(external dose rate & contamination)

Any material that exhibits measurable radiation relatedchanges 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

•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

Part 4. Design 19

Activity:4312 MBq Volume:12 mlActivity concentration; 359 MBq/ml

Date: 2001-10-18 Time: 07.45Signature:SC

Tc99m-MDP

DateDateTimeTimeActivityActivityVolumeVolumeSignatureSignature

Oct 15Oct 1507.3007.3022572 MBq22572 MBq15 ml15 mlSCSC

Tc.generator no: A2376Reference activity: 30 GBq

Reference date: Oct 12 12.00 GMT

<5.0 Sv/h @ surface

<0.05 Sv/h @ 1.0 m

<500 Sv/h, > 5 Sv/h

@ surface

<10 Sv/h @ 1.0 m

>500 Sv/h,< 2000Sv/h

@ surface

> 10Sv/h, < 100Sv/h

@ 1.0m

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.

?????

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.

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.

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.

As done before please answer the following MCQs.

Via Email: Mawya@hotmail.com In-person: basement next to the MRI. For lectures and previous exams

check my web page:www.kau.edu.sa/mkhafaji