Wk 7 Radiation Protection PDF

Radiation Safety and Radiation Protection Oral Sciences Division Thu. Oct. 03. 2024 BMC Radiation safety/Diagnostic Oral Radiology Radiation safety/Diagnostic Oral Radiology Radiation Safety and Radiation protection Dr. Harshkant  Learning Objectives To know i...

Radiation Safety and Radiation Protection Oral Sciences Division Thu. Oct. 03. 2024 BMC Radiation safety/Diagnostic Oral Radiology Radiation safety/Diagnostic Oral Radiology Radiation Safety and Radiation protection Dr. Harshkant  Learning Objectives To know importance of radiation protection To understand various parameters and guidelines for radiation protection To understand responsibility of operator in self and patient protection  Content Patient protection Operator protection Radiation exposure guidelines Radiation protection and patient education  PATIENT PROTECTION Biologic changes after radiation exposure Patient protection is needed to avoid inadvertent exposure So what we can do? – Before exposure – During exposure – After exposure  Before exposure Identify the need to prescribe radiograph Proper equipment Filtration –added + inherent = total filtration Collimation – round or rectangular Position indicating device Selection of technique  During exposure Use of lead for protection Thyroid collar Lead apron Fast films - e speed or f speed films Beam alignment device Exposure factors Selection of technique  LEAD APRON Lead gloves THYROID COLLAR  Lead Apron and Thyroid Collar – A lead apron and a thyroid collar must be used on all patients for all exposures – This rule applies to all patients regardless of age or gender or the number of images being exposed. – The lead apron should cover the patient from the neck and extend over the lap area to protect the reproductive and blood-forming tissues from scatter radiation. – Many states mandate the use of a lead apron.  The thyroid collar – Flexible lead shield that is placed securely around the patient’s neck to protect the thyroid gland from scatter radiation. – The collar may be a separate shield or part of the lead apron. – The lead protects the highly sensitive thyroid gland from scatter radiation. – A low rate of exposure to dental x-rays has not been shown to cause thyroid disease, but the use of collars minimizes the patient’s exposure to x-radiation.  Precautions – Lead aprons and thyroid collars must not be folded when stored. – Folding cause cracks in the lead and allows radiation leakage. – Instead, the lead apron and thyroid collar should be hung up or laid over a rounded bar. Lead apron to be placed on hangers  Image Receptor–Holding Devices (Film holding devices) – The use of an image receptor–holding device keeps the patient’s hands and fingers from being exposed to x-radiation – Hold the image receptor in a stable position and assist the operator in properly positioning the PID.  Beam alignment Well-equipped radiographic unit should have – Appropriate Aluminium filters, – Lead collimators – Position Indicating Devices Equipment should be checked on a regular basis by regulating agencies. Faulty or malfunctioning equipment should be repaired immediately.  Aluminium Filtration – The purpose of the aluminium filter is to remove the low-energy, long wavelength, least- penetrating x-rays from the beam. – These x-rays are harmful to the patient and are not useful in producing a diagnostic-quality image. – X-ray machines operating at 70 kVp or greater must have aluminium filtration.  Collimator – The collimator, used to restrict the size and shape of the x-ray beam to reduce patient exposure – may have a round or a rectangular opening. – A rectangular collimator restricts the beam to an area slightly larger than size 2 intraoral film and significantly reduces patient exposure.  Position Indicator Device (PID) – Used to direct the x-ray beam – Has a round or rectangular shape – Available in two lengths: short (8-inch) and long (16- inch). – The length selected is determined by the imaging technique that is being used. – Long (16-inch) PID is more effective than a short (8- inch) PID in reducing exposure because it causes less divergence (spreading out) of the beam  Exposure Factor – Using the proper exposure factors also limits the amount of x-radiation exposure to the patient. – Adjusting the selectors for kVp, mA, and time controls the exposure factors. – A setting of 70 to 90 kVp keeps patient exposure to a minimum. – On some dental units, the kVp and mA settings are pre-set by the manufacturer and cannot be adjusted.  Proper Technique – Using the correct technique is necessary for ensuring the diagnostic quality of images and reducing the amount of exposure to a patient. – Images that are non-diagnostic must be retaken and results in additional radiation exposure to – Retakes are the major cause of unnecessary radiation to patients and must be avoided.  After exposure Meticulous handling and proper processing of film Avoid retakes If digital images – proper retrieval of image and storage  Pregnancy and radiation protection dental radiographic procedures “do not need to be altered because of pregnancy.” When a lead apron is used during dental imaging procedures, the amount of radiation received in the pelvic region is nearly zero. The embryo or foetus receives no detectable exposure with the use of a lead apron.  Scientific evidence indicates that dental x-ray procedures can be performed during pregnancy, Prefer to postpone x-ray procedures if patient is concerned.  OPERATOR PROTECTION Avoid occupational exposure Must avoid primary beam Distance recommendation – Maintain adequate distance during exposure – Minimum 6 feet away from tube head – When this distance can not be maintained use lead protection barrier – Position yourself at an angle of 90 to 135 degrees from primary beam (position and distance rule)  Lead partition Operator X ray machine POSITION AND DISTANCE RULE  One should not hold the film or tube head in any situation Stand behind protective barrier like wall or leaded shield Monitor machines and equipment for quality Operator monitoring – Use of film badge /radiation monitoring badge  Three types of monitoring devices are used to determine the amount of radiation exposure to personnel: – Film badge – Pocket dosimeter (pen style) – Thermoluminescent device (TLD) Film badge Thermoluminescent device Pocket dosimeter (pen style) FILM BADGES  The dosimeter badge should be worn at all times while the employee is at work. At the end of the radiation exposure monitoring period, usually every 3 to 4 weeks, the badge is returned to the monitoring service company for reporting. The company processes the badge and prepares a dose read report that is returned to the dental office. The dose read report contains the radiation exposure results for the radiation exposure monitoring period, as well as accumulated quarterly, yearly, and sometimes lifetime exposures of the individual. RADIATION EXPOSURE GUIDELINES  ALARA principle As low as reasonably achievable Keep the exposure minimum Minimize risk with all possible measures  Maximum permissible dose US National Council on Radiation Protection (NCRP) International Council on Radiation Protection (ICRP) Occupational Exposure Guidelines- – For occupationally exposed persons – 5 rem/year – General public –0.1 rem/year RADIATION PROTECTION AND PATIENT EDUCATION Answer questions of patient regarding x ray exposure Explain him/her regarding protection measures Display radiation protection/hazard symbols and instructions in radiology room Thank You