# New microsoft office power point presentation b arun kumar

12. Aug 2020
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### New microsoft office power point presentation b arun kumar

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• 6. Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as • "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". • Exposure can be from a source of radiation external to the human body or due to internal irradiation caused by the ingestion of radioactive contamination.
• 8. Protection • Why? • From What? • Whom to protect? • How to protect?
• 10. RADIATION UNITS • ROENTGEN– unit of radiation exposure that will liberate a charge of 2.58x10-4coulombs/kg of air. • Independent of the area or field size
• 11. Absorbed dose • Deposition of energy in pt by radiation exposure • Independent of composition of irradiated material and energy of beam • RAD: unit of absorbed dose • GRAY: SI unit of absorbed dose • Gray defined as the quantity of radiation that results in an energy deposition of 1 joule per kilogram. • I GRAY = 100 RAD • 1RAD = 1 cGY
• 12. Dose equivalent • It is a measure of biological effectiveness of radiation • REM: unit of absorbed dose equivalent • SIEVERT : SI unit • 1 sievert = 100 rems • Dose equivalent=Absorbed dose x QF. • REM = RADS X QUALITY FACTOR
• 13. Quality factor • It is the parameter used to describe the quality of beam. • Gives the amount of energy deposited per unit length travel. Expressed in KeV per micron. Type of radiation Q factor X rays 1 Gamma rays 1 Beta particle 1 Electrons 1 Thermal neutrons 5 Other neutrons 20 Protons 20 Alpha particle 20
• 14. EFFECTIVE DOSE EQUIVALENT • Purpose – to relate exposure to risk • It is calculated by multiplying the dose equivalent received by each individual organ or tissue (DT) by an appropriate tissue weighting factor (WT) and summing for all the tissues involved.
• 17. SOURCES OF RADIATION • Natural radiation: 1. External: Cosmic and gamma radiation 2. Internal: radionuclides with in the body ingested or inhaled • Medical procedures: 1. Diagnostic 2. Therapeutic • Nuclear weapons/industry/accidents
• 19. Primary Types of Ionizing Radiation • Alpha particles • Beta particles • Gamma rays (or photons) • X-Rays (or photons) • Neutrons Ionizing Radiation alpha particle beta particle Radioactive Atom X-ray gamma ray
• 20. Direct Ionization Caused By: • Protons • Alpha Particles • Beta Particles • Positron Particles
• 21. Indirect Ionization Caused By: • Neutrons • Gamma Rays • X-Rays
• 23. Radiation health effects CELL DEATH BOTH TYPE OF EFFECTS CELL TRANSFORMATION
• 24. Radiation health effects DETERMINISTIC Somatic Clinically attributable in the exposed individual CELL DEATH STOCHASTIC somatic & hereditary epidemiologically attributable in large populations ANTENATAL somatic and hereditary expressed in the foetus, in the live born or descendants BOTH TYPE OF EFFECTS CELL TRANSFORMATION
• 25. • Deterministic (Threshold/non-stochastic) • Existence of a dose threshold value (below this dose, the effect is not observable) • Severity of the effect increases with dose • A large number of cells are involved Radiation injury from an industrial source Deterministic effects
• 26. • Permanent sterility • males • females 3.5-6 Gy 2.5-6 Gy • Temporary sterility • males • females 0.15 Gy 0.6 Gy Threshold Doses for Deterministic Effects • Cataracts of the lens of the eye 2-10 Gy
• 27. Stochastic Effects • Stochastic(Non-Threshold) – No threshold – Probability of the effect increases with dose – Generally occurs with a single cell – e.g. Cancer, genetic effects
• 28. CHAIN OF EVENTS FOLLOWING EXPOSURE TO IONIZING RADIATION CELL DEATH DETERMINISTIC EFFECTS CELLULAR TRANSFORMATION MAY BE SOME REPAIR STOCHASTIC EFFECTS exposure ionisation free radicals (chemical changes) molecular changes (DNA,RNA, ENZYMES) SUBCELLULAR DAMAGE (MEMBRANES, NUCLEI, CHROMOSOMES) CELLULAR LEVEL
• 30. Radiosensitivity [RS] • RS = Probability of a cell, tissue or organ of suffering an effect per unit of dose.
• 31. RS laws (Law of Bergonie & Tribondeau) Radiosensitivity of living tissues varies with maturation & metabolism; 1. Stem cells are radiosensitive. More mature cells are more resistant 2. Younger tissues are more radiosensitive 3. Tissues with high metabolic activity are highly radiosensitive 4. High proliferation and growth rate, high radiosensitivty
• 33. Optimization of protection Protection should be optimized in relation to The magnitude of doses, Number of people exposed For all social and economic strata of patients.
• 34. All doses should be kept • As • Low • As • Reasonably • Achievable
• 37. Types Of Barriers Protection is required against three types of radiation: the primary radiation; the scattered radiation; and the leakage radiation through the source housing. A barrier sufficient to attenuate the useful beam to the required degree is called the primary barrier. The required barrier against stray radiation (leakage and scatter) is called the secondary barrier.
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• 42. SHEILDING 42 TECHNOLOGIST . 25 mm LEAD • LEAD APRON, GLOVES • THYROID SHIELD, GLASSES PATIENT – GONAD SHEILDING . 5 mm LEAD
• 43. GONAD SHIELDING • MUST BE . 5 MM OF LEAD • MUST BE USED WHEN GONADS WILL LIE WITHIN 5 CM OF THE COLLIMATED AREA • Male vs. female shielding
• 50. • There are various Regulatory Bodies at the international and National level, which lay down norms for radiation protection. • These are • the International Commission for Radiation Protection ( ICRP), • the National Commission for Radiation Protection (NCRP ) in America, • and the Atomic Energy Regulatory Board (AERB) in India.
• 51. • The International Commission of Radiation Protection (ICRP) was formed in 1928 on the recommendation of the first International Congress of Radiology in 1925. • The commission consists of 12 members and a chairman and a secretary who are chosen from across the world based on their expertise. • The first International Congress also initiated the birth of the ICRU or the International Commission on Radiation Units and measurements
• 52. • The Indian regulatory board is the AERB, Atomic Energy Regulatory Board. The Atomic Energy Regulatory Board was constituted on November 15, 1983. President of India. Section 27 of the Atomic Energy Act, 1962.
• 53. • Radiation safety in handling of radiation generating equipment is governed by section 17 of the Atomic Energy Act, 1962, and the Radiation Protection Rules (RPR) • The “Radiation Surveillance Procedures of Medical Applications of Radiation,” specify general requirements for ensuring radiation protection in installation and handling of X-ray equipment. Guidance and practical aspects on implementing the requirements of this Code are provided in revised documents issued by AERB in the year 2001
• 55. • The responsibility for establishing a radiation protection programme rests with the hospital administration / owners of the X-ray facility • The administration is expected to appoint a Radiation Safety Committee (RSC), and a Radiation Safety Officer (RSO). • Recommended by NCRP that the RSC should comprise of a radiologist, a medical physicist,, a senior nurse and an internist.
• 56. This survey has 5 phases which are Investigation: Inspection: Measurement: Evaluation: Recommendations:
• 57. Depicts the organizational flow chart and the administrative and functional components of radiation protection program.
• 58. Personnel Dosimeters • Desirable characteristics – Should be lightweight, durable, and reliable – Should be inexpensive • Types of personnel dosimeters – Film badge – Pocket ionization chambers – Thermo luminescent dosimeters (TLD)