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Radiation Protect.
CH 1 & 2
Question | Answer |
---|---|
What term is synonymous with ALARA? | (ORP) Optimization for Radiation Protection |
What radiographic exam is the highest radiation dose for a male & female? | Pelvis for male. L-Spine for female. |
1.)What is the greatest source of ionizing radiation? 2.)Of this source, what accounts for most of it? 3.)How much do medical X-rays account for? | 1.) Natural background radiation 2.) Radon accounts for 55% 3.) Medical X-ray accounts for 11% |
1.) What is a CXR's typical adult patient effective dose? 2.) What is the BERT amount? | 1.) 8 mrem or 0.08 mSv 2.) The BERT amount for CXR is 10 days |
What are the radiation units? What are they used for? | Rem-For workers exposure, Rad-for patient's absorbed dose, Gy-absorbed dose, sV-the dose equivalent (1 sV=100 Rem & Rad) |
Which x-ray has the highest bone marrow dose? | The stomach & UGI tract are the highest with a 100 mrad "mean" dose. |
What are the 3 distinct phases of a radiology service? | 1.) A physician's order 2.) Performance of the procedure 3.) Interpretation of the radiologic findings |
1.) What is the most common reason for repeats? 2.) What is the most commonly repeated exam? | 1.) Inappropriate technical factors (kVp, mA, time, AEC) 2.) Spine is most commonly repeated 32% (T-sp 17%, L-sp 8% & C-sp 7%) |
How many sV are = 1 Rem? | 1 sV=100 Rem. So, 1msV=1 Rem. 10 sV=1000 Rem. |
What is Diagnostic Efficacy? | The degree to which the diagnostic study accurately reveals presence or absence of disease in the patient. |
What is attenuation? | The reduction in the number of primary photons in the x-ray beam through absorption. |
1.) What factors do the probability of photoelectric absorption depend on? 2.) When does the probability of photoelectric effect increase? | 1.) Photoelectric effect depends on the energy of the incident x-ray & the atomic # of the irradiated object. 2.) The probability increases as the energy of the incident photon decreases & the atomic # of the irradiated object increases. |
For a typical diagnostic x-ray unit, what is the energy of the average photon in the x-ray beam? | The average energy of the photon in the beam is about 1/3 the energy of the most energetic photon (the kVp is the peak). |
What are the typical bone marrow doses for the following exams in the order from highest to lowest? Skull, C-Spine, Chest, Stomach/UGI, L-Spine, IVP, Abdomen, Pelvis, Extremities | 1.) Stomach/UGI 100 mrad 2.) L-spine 60 mrad 3.) Abdomen 30 mrad 4.) IVP 25 mrad 6.) Pelvis & C-spine 20 mrad 7.) Skull 10 mrad 9.) CHest & Extremities 2 mrad |
What is the difference in the typical gonadal dose between males & females in the following x-ray exams? Stomach/UGI, L-Spine, IVP, Abdomen, Pelvis | L-Spine M 175 mrad F 400 mrad, IVP M 150 mrad F 300 mrad, Abdomen M 100 mrad F 200 mrad, Stomach M <2 mrad F 40 mrad & Pelvis M 300 mrad F 150 mrad |
What is the difference between Alpha & Beta particles? Which particle is more penetrating? | 1.) The origin of alpha particles & beta particles is the difference. Alpha particles originate in the nucleus as 2 protons & 2 Neutrons (Helium). Beta particles originate in the atomic electron shells. 2.) Beta particles penetrate matter to greater depth |
What is the annual U.S. population exposure dose quivalent per year? | Approximately 3 mSv per year (300 mrem) |
Define BERT (Background Equivalent Radiation Time) | Compares the amount of radiation received from a radiologic procedure with the amount of radiation received with natural background radiation over a given period of time. |
What is the biologic damage ionizing radiation? | Ionizing radiation penetrates body tissue by ejecting electrons. Radiation at the atomic level results in molecular change. Molecular damage causes cellular damage. Cellular damage leads to abnormal cell function. |
Which population groups & their biological effects contributed to research & data surrounding radiation doses? | The children & adolescents living in the Ukraine region. Over 1700 cases of thyroid cancer were dx between 1990-1998. 32,00 people who lived within 5 miles of 3MI who were exposed to low levels of radiation from the accident. |
What major nuclear product is a concern for the thyroid? | 131 I (Iodine 131) or Radioactive Iodine |
1.) On the electromagnetic spectrum what uses have the lowest frequencies to the highest? 2.) Of the electromagnetic radiation, which 2 are classified as ionizing radiation? | 1.) Radio, Microwave, Infrared, Visible Light, Ultraviolet, X-ray, Gamma Ray 2.) X-Ray's & Gamma Ray's are classified as ionizing radiation |
What is Terrestrial Radiation? | Terrestrial radiation is from the radioactive materials in the crust of the earth. |
What is Cosmic Radiation? | Cosmic radiation is from the sun (solar) & beyond the solar system (galactic). |
What is Internal Radiation? | Internal radiation is from radionuclide's & radioactive atoms that make up a small % of body tissues. |
What are the 3 types of Natural Radiation? | Terrestrial Radiation, Cosmic Radiation, Internal Radiation |
1.) What percentage does Natural Radiation contribute to the effective dose? 2.) What is the dose amount in mSv & mrem? | 1.) As a total, Natural Radiation contributes 82% of the equivalent dose. 2.) 2.95mSv & 295 mrem |
Which are the most radiosensitive blood cells? | Lymphocytes |
What level of Radon should be avoided in homes? | Anything above 4 pCi/L (4 picocuries per liter). The yearly equivalent dose to the lungs is 0.05 mSv or 5 mrem. |
How can Radon enter houses? | Radon is a gas that percolates up through the soil. It enters buildings through cracks or holes in the frameworks. Building materials contain Radon. It may gain access through crawlspaces under living areas, through floor drains & sump pumps. |