RADBIO Flashcards
1
Q
- 1 meter = ______ Centimeters = ______ Inches
- Centermeters to Inches:
- 1 Kilogram = ____ lbs
A
- 1 meter = 100 centimeter = 39.37in
- 2.54cm = 1in
- 1kg = 2.2lbs
2
Q
- Farenheit to Celcius:
- Celcius to Farenheit:
- Law of Conservation of Energy:
- Smallest subdivision of element:
A
- C = 5/9 (F-32)
- F = (9/5 * C) +32
- Matter can not be created or destroyed, only can be changed from one form to another
- Atom
3
Q
- Proton vs Neutron Charge in Nucleus:
- Z =
- A =
- Where are electrons?
- Their Charge?
A
- Proton = Positive / Neutron = Neutral
- Anatomic Number (Number of Protons in Nucleus)
- Anatomical Mass (Sum of Protons)
- Orbital shell outside nucleus
- Negative
4
Q
- Closer electrons is to nucleus, the ______ binding energy
- What is valence?
- Formula to calculate electron limit:
A
- Stronger
- Number electrons in outter most shell
- 2n2 (n is number of shells counting from nucleus, K-Shell being 1)
5
Q
- What are 4 conditions needed to produce x-ray
A
- A Source Free Electrons (Thermionic Emission)
B. Acceleration Electrons (kVp moves electrons Cathode to Anode)
C. Focus of Electrons: (Focusing Cup in Filament)
D. Deceleration of Electrons (Striking Anode)
6
Q
- What is a space charge?
- Filaments are located:
- How is electron energy converted to kinetic?
- What material is Anode? Why?
A
- Released Electrons in tiny cloud around filament wires
- Cathode
- Accelerated electrons must be stoped/slowed down
- Tungsten b/c high atomic # & high melting point
7
Q
- Interactions That Occur At The Anode:
- Compare the 2:
A
- Bremsstrahlung & Characteristic
A. Bremsstrahlung = xray produced when accelerated electron slowed/stopped by tungsten atom
- Lost energy of electron converted to heat or x-ray energy.
- Energy of xray equal to energy of lost electron
B. Charachteristic = xray produced when accelerating electron knocks out k-shell electron (inner shell) of tungsten
- Accelerated electron striking must have kEV of 70
- Electron from another shell drops down, creating photon
8
Q
- X-Ray is what type of radiation?
- Difference between X-Ray & Gamma Rays?
- X-Ray Frequency Means:
- Desired
- Frequency measured in:
A
- Electromagnetic
- ORIGIN: XRay outside Nucleus, Gamma Ray in Nucleus
- Number times per second electric & magnetic field regenerate themselves
- DESIRED: High Frequency - Hertz (Hz)
9
Q
- X-Ray Wavelength Means:
- Desired:
- Unit: - Relation between Wavelength & Frequency
- X-Ray Beam is Described in terms of _______ & ______
A
- Distance between peaks / distance between regenerations
- SHORT Wavelength
- Angston
- SHORT Wavelength
- INVERSE (As frequency increases, wave length decreases)
- Quality & Quantity
10
Q
- Quality of Beam Means:
- Controlling Factor:
- Quantity of Beam Means:
- Controlling Factor:
- Primary vs Remnant Beam:
A
- Energy of photons / ability penetrate
- kVp
- Higher kVp = higher quality - Number of photons
- mAs
- Higher mAs = Higher quantity - Primary = Xrays produced in tube
- Beam BEFORE striking patient
- Consist of Brems or Characteristic
Remnant = AFTER exiting patient
- Consist of primary & scatter
11
Q
- Explain Inverse Square Law
- Formula:
- When Distance Doubled =
A
- Intensity of Beam will vary depending on distance from tube’s focal spot
- Inv. Square Law is used to determine intensity of beam at various distances
- Beam diverges as it leaves focal spot, the further from the tube = the more divergence = less intensity - Law: i/I = D2/d2
(i is the intensity at distance d from the source, I is the intensity at distance D from the source) - When distance is doubled, intensity is REDUCED 4x
- When distance HALVED, intensity is MULTIPLIED 4x
- When distance is doubled, intensity is REDUCED 4x
12
Q
Properties of X-Ray Photons:
A. Travels In:
B. Penetrating Ability:
C. Charge:
D. Wavelengths:
E. Travel Speed:
F: Effects:
A
A. Straight Lines
B. Highly Penetrating
C. Electrically Neutral
D. Heterogenous (varying)
E. Speed of Light
F. Ionizing
- Fluoresce some crystals
- produce scatter and radiation
13
Q
- Compton Interaction
- AKA:
- Occurs: - Photoelectric Absorption
- Occurs: - Coherent Scatter
- AKA:
- Occurs In:
A
- Compton Scatter
- Xray removes electron from outer shell & proceeds in different direction
- Removal of electron causes ionization / biological Effect - X-Ray absorbed by inner-shell electron
- Causes Ionization / biological damage - Classical Scatter
- Low energy xray interacts with electron
- No ionization occurs / no biological affect
14
Q
- Define Attenuation
- NRCP Stands For
- What is their function?
- Types of Doses:
A
- Reduction in intensity of beam due to absorption, scatter & divergence
- National Council on Radiation Protection
- Sets standards for measurements and protection from radiation
- Absorbed dose, dose equivalent, exposure, effective dose, & air kerma
15
Q
- Absorbed Dose
- What Is It:
- SI Unit:
- Conversion: - Dose Equivalent
- What Is It:
- SI Unit:
- Conversion:
A
- Dose in tissue received by humans from source
- gray (Gy)
- 1 Gy = 1 Joule of energy per kg - Absorbed dose x Radiation Weighing Factor
(Xray/Photon: 1, Alpha =20)
- Sievert (Sv)
- mSv = 1/1000 Sv
16
Q
- Exposure
- What Is It:
- SI Unit:
- Measured With: - Effective Dose:
- What Is It:
- SI Unit:
- Conversion:
A
- Direct measurement of electrical charge generated by ionization of air molecules
- Coulomb/kg
- Ion Chamber - Sum of organ/tissue doses x tissue weighting factor
- Sv
17
Q
- Air Kerma
- What Is It:
- SI Unit: - Tissue Weighing Factors:
Gonads:
Breast:
Red Bone Marrow:
Lung:
Thyroid:
Bone:
Other Organs: - Above are taken into account for:
A
- Kinetic energy release in matter
- gray (Gy) - Tissue Weighing Factors:
Gonads: .8
Breast: .12
Red Bone Marrow: .12
Lung: .12
Thyroid: .4
Bone: .01
Other Organs: .12 - Effective Dose
18
Q
- _______ - radiation increases in severity with an increase in radiation dose
- ______ - Incidence of radiation response increases with increasing radiation dose
- Which have a threshold? Which doesnt?
- Which occurs in days?
- Which occurs in months.years?
A
- Deterministic
- Stotachtic
- Determenistic = Threshold
Stotastic = Probabilty (no threshold) - Deterministic = days
- Stotastic = months/years later
19
Q
- What dose-response imaged?
- _______ - Radiation dose is doubles, response to radiation doubled (directly proportional)
- ________- Responses increase rapidly or taper off as dose increases
A
- LINEAR, NON-THRESHOLD
- Linear
- Non-Linear
20
Q
- What dose-response imaged?
- ______ - Takes certain dose before response will manifest
- Acute Radiation Syndrome Occurs When:
A
Linear Threshold
- Threshold
- Whole Body Dose must be greater than 1 sievert
21
Q
- What dose-response imaged?
- ______ - any dose has potential to cause response / no safe dose
- What affect radiosensitivity the most?
A
- non-linear, non-threshold
- non-threshold
- Cell Maturity / Rate of Division
22
Q
- What dose-response curve imaged?
- More Radiosensitive Cells Are:
- LET stands for:
A
- Nonlinear - Nonthreshold
- Young / Rapidly Dividing
Ex: Fetus - Linear Energy Transfer
23
Q
- What is LET?
- What is LET relation to RBE?
- What has high LET?
- What has low LET?
A
- Rate of which energy transferred to tissue as radiation passes
- DIRECT PROPORTIONAL
- More energy transferred, more ionization occurs, more biological effect - High = Alpha, Beta & Nuetrons
- Low = Xray / Gamma
24
Q
- What does RBE stand for?
- What is RBE?
- What affects RBE?
A
- Relative Biological Damage
- Describes capability of various radiation to produce biological effect
- Type of radiation dose rate and type of tissue
25
1. List Tissues/Organs from MOST Sensitive to LEAST:
gonads, nervous tissue, lymphoid tissue, muscle tissue, kidney, liver, bone marrow, epitheal tissue, thyroid, growing bone
MOSTv
Lymphoid Tissue
bone marrow
gonads
epithelial tissue
growing bone
kidney
liver
thyroid
muscle tissue
nervous tissue
LEAST^
26
1. High-Risk Exams For Women. (3)
2. High-Risk Exams For Men. (3)
3. Special Concerns For Pediatrics Include:
1. B.E, L-Spine, IVU
2. Hip/Pelvis, L-Spine, IVU
3. Biological Effects, Reduce number of views, do NOT do comparison views
27
1. Difference between high doses & low doses to cell survival:
2. how can cells that have been damaged by sublethal doses of radiation be repaired?
3. What is LD50?
4. What is LD50/60?
- What is the number for LD50/60?
1. High = kills, Low = damages
2. Enzymes
3. LD50 = dose whole body radiation that will kill 50% exposed population
4. LD50/60 = 50% of exposed individuals will die within 60 days
5. LD50/60 = Whole Body Dose of 3.5 Sv
28
1. Oxygen & Cell Sensitivity Relation:
2. Why?
3. What is OER
4. OER Relation to LET
1. Well-Oxygenized Cells are MORE sensitive to radiation
2. Oxygen creates additional free radicals which increase damage to cells
3. Oxygen Enhancement Ratio - ratio of hypoxic doses to oxygenated doses to achieve same biological affect
4. Low LET = OER 3
Fast Nuetrons = OER 1.5
High LET = OER 1
29
1. What LET is X-Ray? OER?
2. Somatic Effects Refer To:
3. What are germ cells?
- Includes:
1. Low LET, OER 3
2. All non-reproductive cells or tissues
3. Reproductive cells or tissue
- Oogonium & spermtogonium
30
1. Mitosis process of _______
2. Phases Consist of: (names only)
3. Most radiosensitive phase:
4. What forms/occurs & results:
1. SOMATIC Cell Division
2. Prophase, Metaphase Anaphase, Telophase, Interphase
3. Metaphase
4. 2 Parent Cell Divide
- Form 2 Identical Daughter Cells
-23 Pair Somatic Cells / 46 Chromosomes
31
1. Germ cells undergo what division?
2. Same or different than somatic cells? how?
3. What is Result of Meiosis?
4. Haploid vs Diploid?
1. Meiosis
2. Same at somatic except it goes through another phase without DNA duplication)
3. Four Identical Granddaughter Cells
-23 Chromosomes
4. Diploid: 23 pairs (46 chromosomes)
Haploid: 23 chromosomes
32
1. DNA located in:
2. RNA located:
3. Bulk of Cell Made of:
4. Energy for cell:
1. Nucleus
2. Mostly Nucleus but also nucleolous
3. Cytoplasm
4. Mitochandria
33
1. What are protein synthesizers?
2. Target molecule for radiobiology
3. Direct vs Indirect Effect:
4. Which occurs more?
1. Ribosomes
2. DNA
3. Direct: Radiation strikes DNA directly
Indirect: Radiation strikes water molecule which releases free radicals that then strike DNA
4. Indirect
34
1. Short Term Effect Occur:
- AKA
- Examples:
2. Long Term Effects Occur:
- AKA:
- Examples:
1. biological effects occur shortly after an exposure
- Early Effects
- Skin Erythema & Desquamation (peeling)
2. biological effects dont occur for years after exposure
- Late Effects
- Skin Cancer
35
1. Acute Effect
- Occurs:
- Example:
2. Chronic Effect:
- Occurs:
- Examples:
1. Sudden Onset
- Large Radiation Exposure
- Acute Radiation Syndrom
2. Occurs over time / prolonged / Late in life
- Low levels radiation over long period time
- Cancer, Leukemia
36
1. What is carciogenisis
2. Most common:
3. What is most common in atomic bomb survivors?
4. Lung cancer often occurs in:
1. Induction of cancer by agent (radiation) causing rapid growth of cells
2. Leukemia
3. Leukemia
4. Mine workers inhaling radon gas
37
1. What is cataracts
2. What are examples of non-linear, threshold responses to radiation:
- What dose:
3. What is higher risk for cancer, breast tissue or bone marrow?
4. What are human reproductive organs referred to as?
- Dose required to cause temp. sterility?
- Permanent?
1. Opacity of lens of eye
2. Cataracts & Thyroid Cancer
- 1 gray
3. Breast Tissue
4. Gonads
- 2 Gy
- 5 Gy
38
1. Dose required for nonlinear, threshold:
- Example:
2. Doses required for temporary sterility of gonads? permanent?
3. Acute Radiation Syndrome Affect: (3)
4, When is embryonic stage?
1. 1 Gy
- Cataracts & Thyroid Cancer
2. Temp = 2 Gy. / Perm = 5 Gy
3. Hemopoietic, GI & CNS
4. 2-8 weeks
39
1. Hemopoietic System:
- Includes:
- Principle Response to Radiation:
2. Most Radiosenstive Cells:
3. Most Bone Marrow Located:
- Examples:
4. Why is GI radiosenstive?
- What occurs with large exposure to GI?
1. bone marrow, circulating blood, lymphnodes, spleen and thymus
- decrease in number of types of blood cells in circulation
2. Lymphocytes & Spermatogonia
3. Flat Bones
- Pelvis, Ribs, Skull, T&L Vert.
4. Lining divides rapidly
- Nausea Vomiting & diarrhea
40
1. Acute Radiation to GI Tract Results In:
2. How much radiation required to affect CNS?
Why?
3. Fetus most sensitive:
4. Possible Biological Effects to Fetus in Radiation:
1. Nausea, Vomiting & Diarrhea
2. High-Dose
- because they dont divide and are considered radio-resistent
3. First Trimester
4. prenatal death, neonatal death, congenital abnormalities, malignancy induction, general
impairment of growth, genetic effects, and mental retardation
41
1. What is GSD?
2. Goals of Gonadal Shielding:
3. What doses are harmful to germ cells?
4. What effects gonad effects to radiation?
1. Genetically Significant Dose
- Estimated Dose Received by Population
2. Prevent mutations in future generations
3. Any amount / dose of radiation
4. Rate Delivered (Protraction) & Time Between Exposures (Fractionation)
42
1. What is protraction?
2. What is fractionation?
3. Who is less sensitive to genetic effects of radiation?
1. Rate Delivered (Protraction)
2. Time Between Exposures (Fractionation)
3. Female less sensitive
43
1. Contrast of image is controlled by:
2. Why is higher kVp used in digital imaging?
3. What does AEC control?
4. When an exposure is made, _______ & _______ is required
1. LUT
2. To compensate for slower digital systems
3. Exposure TIME (tech selects mA) - but because it controls the time, it inevitably controls mAs
4. Audible sound & visible light
44
1. Reproductive Shields should be used when:
2. With shielding, how much is exposure reduced in men? women?
3. Type of shields:
4. Where are shields placed?
1. A. Reproductive Organs are within 5cm of properly collimated beam
B. Reproductive Age
C. Amount Patient is Exposed (KUB vs IVU)
2. 90% male, 75% female
3. flat contact, shaped contact, shadow shield & protective lenses
4. Where radiographic image will not be compromised
- Gonads, Breast & Bone Marrow (Flat Bones) most sensitive / should be shielded whenever possible
45
1. Gonad shields should be used when primary beam is within ____
2. When is shadow shield used?
3. Primary purpose of collimation is to:
4. Types of collimation devices:
1. 5cm
2. Sterile field / doesnt touch patient
3. Restrict primary beam to ROI to decrease patient dose & reduce scatter (which improves image contrast)
4. Collimator (manual & Automatic)
- Cones, Cylinders
- Diaphragms & apertures
46
1. Filters effect on exposure to skin/organ:
1. Filters effect on beam energy:
3. Based on NRCP, x-ray machines must have _____ filtration
4. How is beam filtration determined?
1. Reduces by filtering low energy / harmful xrays
2. Filters low energy xrays from beam, increasing average energy
3. 2.5 mm Al equivalent
4. By half-value layer test
47
1. Imaging receptor used in CR:
- In DR:
2. In fluro, exposure must not exceed:
- In high-level fluro:
3. How to limit patient exposure during fluro:
1. Photostimuable Phosphur Plate
- DR: Indirect Flat Panel Detectors, Direct Flat Panel Detectors & CCD
2. 100 mGy/min
- HIGH = 200 mGy/min
3. Reduce spot films, limit magnification mode & tightly collimate
- used last image hold
48
1. Fluro timer activated:
2. What is intermittent fluroscopy?
3. What is ABC?
4. What does it adjust / how?
1. 5 min cumulative exposure
2. radiographer periodically activates beam instead of continuous
- also uses last image hold
3. Automatic Brightness Control maintains image brightness by adjusting for part thickness
4. Adjust part thickness by automatically varying kVp and/or mAs
49
1. How does ABC reduce patient exposure?
2. Fluro Source-to Skin Distance (SSD) can not be less than
- Stationary:
- Mobile:
3. In C-Arms / Mobile Fluro - how is tube positioned?
- Why?
4. What is LIH?
- Why used?
1. Adjust technical factors automatically, which is faster than manually = which reduces flouro time = which reduces patient exposure / dose
2. Stationary 38 cm (15in)
- Mobile: 30 cm (12in)
3. Tube under patient & Image Intensifier close to patient as possible
- Tube under patient results in scatter towards floor and away from patient/workers
4. Last Image Hold displays last frame on screen while beam is off
- designed to reduce radiation dose to patient
50
1. What is DAP?
2. Where does "backscatter" source from?
3. What is leakage radiation?
4. Leakage radiation must not exceed:
1. Dose Area Product - measure radiation i=to air times the area of xray field
2. Walls/Doors/ Equipt, etc....
3. Radiation leaves tube other than window
4. 1 mGy/hr @ 1 meter from tube
51
1. Principle Methods of Protection:
- Explain Each
2. If distance is doubled, exposure is ______
3. At one meter from patient, at right angle to beam - scatter intensity is ____% of ______
4. Desired distance to be away from source (patient / tube)
1. Time Distance Shielding
- Spend little time around radiation
- Far from source as possible
- Shield yourself with led / stand behind booth
2. exposure reduced four times (1/4)
3. 1% or primary beam
4. At least 2 meters / 6 feet
52
1. Primary vs Secondary Lead Barriers
- Protects Against
- Location
- Requirements
1. Primary = protects against primary radiation
- located perpendicular to the x-ray beam.
- 1/16in Lead
- 7 feet upward from floor
Secondary =protects against scatter / leakage radiation
- 1/2 inch overlap
- 1/32 inch lead
53
1. What is control booth barrier classified as?
2. What should occur before beam hits booth barrier?
3. What is requirement for cord in fixed/stationary xray?
- Mobile?
4. Clear-Lead Plastic Barrier is ___% lead, & ____ feet from floor
1. Secondary barrier
2. Should scatter min. 2 times before reaching
3. Short so tech has to be behind to expose
- Long / 6 feet so distance is possible for exposure
4. 30% 7 feet
54
NRCP LEAD EQUIVALENTS
- Apron
- Gloves
- Primary Barrier
- Secondary Barrier
the current NCRP #102 recommends the following:
lead aprons shall be .5 mm Pb
lead gloves shall be .25 mm Pb
Primary barriers shall be 7 ft high, 1/16" thick
Secondary barrier, Pb 1/32" thick extended to the ceiling
55
1. Where should you stand during mobile exposure?
2. SSD Recommended in Mobile X-Ray?
- Minimum?
3. What is purpose of drapes in fluro?
- Lead Equivalent:
4. What is purpose of bucket slot cover in fluro?
- Lead Equivalent:
1. right angle from patient
2. 15 in recommended
- 12 in minimum
3. Reduce over table scatter from reaching operator (occupational exposure reduced / not patient)
- .25 mm Pb
4. Reduce under table scatter from reaching operator (occupational exposure reduced / not patient)
- .25 mm Pb
56
1. Type of switch for cumit. timer in fluro:
2. Lead Equivalents:
- Buckey Slot Cover
- Protective Drapes:
3. What is NRCP stand for?
- NRC?
- CFR-21?
4. What do they do?
- What is FDA's role?
1. Deadman (required continious pressure
2. .25 mm Pb
- .25 mm Pb
3. The National Council on Radiation Protection (NCRP),
The Nuclear Regulatory Commission (NRC),
Congressional Federal Register (CFR-21)
4. Set standards for the use of ionizing radiation.
The NRC also regulates the uses of nuclear materials such as nuclear medicine through licensing, inspection of manufacturing
standards and enforcement of its requirements.
- The Food and Drug Administration (FDA) conducts inspections of institutions to determine if the radiographic equipment meets standards.
57
1. ABC provides Max _______ & Min ______
2. Types of badges:
3. Where & how is radiation monitor/badge held?
4. If pregnant where is badge?
1. Max brightness & Min exposure
2. Film Badge, TLD, Pocket Dosimeter, & OSL
3. Collar / Waist outside apron
- Always in same spot (not chest one day and waist next day)
- Proper Side forward
4. Second badge given, worn waist level UNDER apron
58
1. Film Badge
- Exposure Levels:
- Made Of:
- Pros:
- Cons:
2. Thermoluminescent Dosimeter
- Exposure Levels:
- Made Of:
- How Does It Work?
3. Is Film badge proportional or inproportional?
- TLD?
1. Film:
- Less than 1 mSv
- Aluminum & Copper Filters
- Inexpensive
- Heat and Humidity Cause Fog
2. TLD
- Less than .05 mSv
- Lithium Fluoride Crystal
- TLD absorbs energy of radiation exposure & stores in form of electrons in crystalline
- When heated, electrons return to normal stage and emit light
3. Both are proportional to exposure recieved
59
1. What is key benefit to a pocket dosimeter?
2. Optically Stimulated Luminescent Dosimeter
- Exposure Levels:
- Made Of:
- Pros:
- How does it work?
1. Pocket Ionization Chamber has immediate mR reading
2. OSL
- .01 mSv
- Powdered Aluminum Oxide
- Pro: eliminate need for film badges
- Certain crystals luminance when exposed to radiation
60
1. How is occupational exposures calculated by NRCP? Why?
2. Who is in charge of monitoring devices?
3. Who must wear a radiation monitor?
4. Who evaluates dosimetry records? How often are the reports?
1. Uses a control monitor stored in a non-radiation area; the background exposure from the control monitor is subtracted from each participant’s monitor (to account for background radiation)
2. the monitoring of devices, radiation sources, and radiation safety is performed by the Radiation Safety Officer
3. Individuals with probability of exceeding 10% of annual dose
4. Physicist or RSO - Monthly Reports
61
1. What is occupational exposure limit per year:
2. Lifetime Cumulative Effective Dose:
3: Annual non-occupational dose of continuous (or frequent) Exposure:
4. Annual non-occupational dose of Infrequent Exposure:
1. 50 mSv / year
2. Age in Years x 10 mSv
3. 1 mSv annually
4. 5 mSv annually
62
1. Fetus can not be exposed more than:
2. Annual Dose Limits For:
- Under 18 y/o Student:
- Whole Body:
- Lens of Eye:
- Extremities:
- Skin:
1. .5 mSv per month
2. Annual Dose Limits For:
- Under 18 y/o Student: 1 mSv / year
- Whole Body: 50 mSv / year
- Lens of Eye: 150 mSv / year
- Extremities: 500 mSv / year
- Skin: 500 mSv / year
63
**REVIEW**
1. Process of cell meiosis results in cells with ____ chromosomes each
2. ______ is a stochastic effect of radiation
3. What is common material of tabletop in radiographic exam room? why?
4. If a response to radiation is expected, no matter how small the dose, then that dose-response is _________
1. 23
2. Cancer
3. Carbon Fiber = Radiolucent as possible / absorbs min. radiation & reducing patient dose
4. non-threshold
64
**REVIEW**
1. Which two interactions between radiation and matter may result in the production of small-angle scatter?
2. Core Temperature of Human Body:
3. X-rays are a form of which of the following kinds of radiation?
4. When the time spent in a higher radiation area is reduced or limited, occupational exposure
1. Coherent & Compton Scattering
2. 37* C
3. Ionizing
4. Also Reduced (DIRECT RELATIONSHIP)
65
**REVIEW**
1. The only principal molecules in the body which are simple molecules are __________ molecules.
2. During which x-ray examinations should a radiographer always wear a thyroid shield?
3. Which of the following terms are synonymous in relation to computed tomography?
A. Diagonal. B. Helical. C. Spiral
4. Which of the following are advantages of the personnel digital ionization dosimeter?
A. Instant access to reports
B. No waiting time for mailing dosimeters
C. Lightweight and durable
D. Can be dropped or scratched with little chance of harm to the device
1. Water
2. Fluro & Special Procedures
3. B & C Only
4. ALL ABOVE
66
**REVIEW**
1. What is the most common unit of measure of equivalent dose?
2. Which part(s) of a diagnostic x-ray unit should not be touched while a radiographic exposure is in progress?
3. The most radiosensitive cells in the hematopoietic system of the human body are the _________________.
4.The human dose-response relationship at low ranges of radiation is calculated using _______________________.
1.Millisievert (mSv)
2. Tube housing, collimator & high-power tension cables
3. lymphocytes
4. Extrapolation from High Ranges
67
**REVIEW**
1. For mammography molybdenum filters allow a (an) _________________ than rhodium filters.
2. Which provides the basis for determining whether an imaging procedure or practice is justified?
3. The tissue weighting factor has a higher value for tissues with more ______________.
4. The lethal effects of cell irradiation are measured by cell _______________.
1. Lower Energy Window
2. Diagnostic Efficacy
3. Radiosensitivity (high TWF = Higher Radiosensitive.)
4. Survival
68
**REVIEW**
1. The dose equivalent limits for radiation workers are based on the radiation received from what source(s)?
2. Radioiodide tablets that dissolve in the bloodstream permit an escape of some radioactivity through
A. the pores of the skin. B. urination. C. vomiting
3. Genetic effects from exposure to ionizing radiation occur as a result of radiation-induced damage to the DNA molecule in which of the following?
A. Sperm of a man. B. Ova of a woman. C. Somatic cells of men and women
4. Luminance is determined by measuring the concentration of light ___________
1. Occupational Exposure
2. A, B & C
3. A & B Only
4. Over a particular FOV
69
**REVIEW**
1. Tissues that are ____________ with a _______ metabolic rate are more radiosensitive.
2. What is the minimum requirement for filtration on x-ray equipment operating above 70 kVp?
3. According to target theory, the target molecule of a cell is _____________________.
4. Exposure is measured by multiplying _________________ by ___________________.
1.immature , high
2. 2.5 mm Al equivalent
3. DNA in nucleus
4. Exposure Rate x Exposure Time
70
**REVIEW**
1. Which term involves a random effect of ionizing radiation?
2. One of the most radiosensitive tissues in the body is ____________ tissue.
3. During a radiation emergency, if the dose rate exceeds ____________, emergency personnel should await specific instructions from radiation experts on how to proceed.
4.Data showing radiation-induced human genetic abnormalities __________________.
1. Stochastic
2. Lymphoid
3. .1 Sv / hour
4. does not exist
71
**REVIEW**
1. What is an Sv?
2. The effective dose (EfD) limiting system supersedes
3. Fluorescent radiation is also known as
4.What do the highly organized enzymes in the inner membranes of the mitochondria break down?
A. Carbohydrates. B. Fats. C. Proteins
1.A radiation unit in the SI system used to measure dose equivalents for occupational exposure
2. the maximum permissible dose (MPD) system.
3. Characteristic Radiation
4. ALL ABOVE
72
**REVIEW**
1. Which of the following results in all-directional scatter?
2. Events that can occur on the cellular level as a result of radiation exposure include:
A. cell death. B. cellular malfunction. C. mitotic failure.
D. mitosis resulting in abnormal daughter cells.
3. The protective tube housing serves as a shield against _____________________ entering the x-ray tube, thereby preventing electric shock while also facilitating cooling of the x-ray tube.
4. If 400 people receive an average effective dose of 0.25 Sv, what is the collective effective dose?
1. Compton Interaction
2. ALL ABOVE
3. High Voltage
4. 100 person - Sv
(400 x .25) = Collective Effective Dose
73
**REVIEW**
1. A device that is commonly used to locate and measure the intensity of a radioactive material in an area is a(n) _________
2. A dose of 10 Gy given to a patient in 5 doses of 2 Gy per day is a ____________ dose.
3. Which action of ionizing radiation is most prevalent and most harmful to the human body?
4. A tenth-value layer is equal to ________ half-value layers.
1.Geiger-Müller counter.
2. Fractionated
3. Indirect Action (Radylosis of Water)
4. 3.3
74
**REVIEW**
1. The atomic number of an element is symbolized by the letter _____.
2. What do agents such as specific chemicals, viruses, and ionizing radiation have in common?
3. If oxygen is present during high-LET radiation the effect of radiation is __________.
4. Antibodies are protein molecules produced by specialized cells in the bone marrow called
1. Z
2. They are all mutagens that may increase the frequency of mutations.
3. The Same
4. Lymphocytes
75
**REVIEW**
1. The atomic number of molybdenum is 42 and the atomic mass number is 98. How many neutrons does it have?
2. As LET ____________, the RBE ______________.
3. The law of Bergonie and Tribondeau states that cells are more radiosensitive if they are
A. highly mitotic. B. primitive and undifferentiated. C. mature cells. D. larger in size. E. nonnucleated.
4. During the process of coherent scattering, an incident low-energy x-ray photon interacts with ____________
1. 56
(Atomic Mass - Atomic Number = Neutrons)
(98 - 42 = 56)
2. Increases - increases (direct relationship)
3. A & B Only
4. an atom and may transfer its energy by causing some or all of the electrons of the atom to momentarily vibrate and radiate energy in the form of electromagnetic waves.
76
**REVIEW**
1. The simplest way to measure patient dose is to measure the __________________.
2. The advantage(s) of using thermoluminescent dosimeters is/are:
3. When performing a mobile radiographic procedure, to reduce the radiation exposure to the patient, the radiographer must use a minimal source-skin distance of ______
4. A codon is a _______________.
1. Entrance Skin Dose
2. Small Size & Tissue Equivalent Response
3. 30 cm
4. Genetic Message
77
**REVIEW**
1. Human cells cannot recover from radiation damage after there is ________________.
2. Bone marrow dose is measured ______________________.
3. Some procedures increase the radiographer's risk of exposure:
4. Annual occupational effective dose (EfD) of __ (_)for whole body.
1.Interphase Death
2. Estimated ESE
3. General Fluoro
Interventional Procedures
Mobile Exams
General Radiographic Exams
C-Arm Fluoro
4. 50 mSv (5 rem)
78
**REVIEW**
1. Cummulative effective dose (CumEfD) limit for the whole body is
2. The annual occupational EfD limit of __(_) is the upper boundary limit.
3. General population limit is ________ for continuous or frequent exposure and ________ for infrequent annual exposure.
4. The annual occupational EfD limit of _ is the upper boundary limit.
1. age in years times 10 mSv (years x 1 rem).
2. 50 mSv (5 rem)
3. 1 mSv (0.1 rem). /. 5 mSv (0.5 rem)
4. 50 mSv (5 rem)
79
**REVIEW**
1. General population limit is _ for continuous or frequent exposure
- Infrequent:
2. ALARA means:
3. As a result of Compton scatter from the patient, at a distance of _________, the scattered intensity is generally _______ of the intensity of the primary beam.
4. When a x-ray beam is properly filtered,______ are removed.
1. 1 mSv (0.1 rem)
- 5 mSV (0.5 rem)
2. As low as reasonably achievable
3. 1 m (3.3 ft) / 1/1000 (0.001)
4. Low-Energy Photons
80
**REVIEW**
1. High speed image receptors require __ mA, which results in fewer scattered photons being available to produce Compton scatter.
2. Monthly EqD to the embryo-fetus does not exceed __
3. Maternity protective aprons consist of_____ mm lead eq
- also have an extra _ mm lead eq. protective panel at waist
- Wrap around protective aprons of _ mm lead eq. also used
4. Inverse Square Law states:
1. Lower mAs
2. .5 mSv (.05 rem)
3. 0.5 mm Pb
- 1 mm Pb
- 0.5 mm Pb
4. The law states: "the intensity of radiation is inversely proportional to the square of the distance."
81
**REVIEW**
1. If the peak energy of the x-ray beam is 100 kVp, a protective lead apron must be equivalent to a least ______mm lead.
- Recommended: _____or_____
- ______ mm lead eq. is the most widely used.
2. Thyroid shield SHOULd be:
3. Clear Glass Lead Equivalent:
4. Housing enclosing the x-ray tube must be constructed so that leakage radiation measured at a distance of ________ from the x-ray source does not exceed ________when the tube is operating at its highest voltage at the highest current that allows continuous operation.
1. MIN = 0.25 mm Pb
- Rec = 0.5 - 1.0 mm Pb
- Common = 0.5 mm Pb
2. 0.5 mm Pb
3. 0.35 mm Pb
4. 1m (3.3 ft) - 100 mR/hour
(100 mR/hour @ 1 meter from tune **)
82
**REVIEW**
1. A protective apron of at least _ mm lead eq. must be worn during all fluoro procedures.
2. Protective lead gloves of at least _ mm lead eq. should be worn when hands are placed near the fluoroscopic field.
3. A protective curtain or sliding panel, should be a minimum of_____ mm lead eq, and should be positioned between _________
4. Buckey Slot Cover should be at least ______ mm lead eq.
- This shielding protects _______________
1. 0.5 mm Pb
2. 0.25 mm Pb
3. 0.25 mm Pb
- the radiologist and the patient to intercept scatter from the patient.
4. 0.25 mm Pb
- the radiologist and radiographer at the gonadal level.
83
**REVIEW**
1. Standing at ________ to the patient, when factors of distance and shielding have been accounted for, is the place with the least amount of scatter.
2. ____ exposure is greater than ______ scatter
3. The location of lower scatter is on the side of the patient away from the ________.
4. Positioning with the ______ over the table and ______ underneath the patient results in higher exposure to the patient and increased scatter.
1. Right Angle / 90*
2. Entrance --- Exit
3. x-ray tube
4. Xray Tube Over / Image Intensifier Under
84
**REVIEW**
1. From the perspective of increased radiation safety, it is best to reverse the c-arm and place the tube ________ the table and image intensifier _______ the patient.
2. When image ________ are used, beam on time decreases and exposure decreases.
3. If the image intensifier is placed ______ the patient as possible, the required fluoro x-ray beam intensity is minimized.
- Also function more effectively as a ______ barrier between the patient and the operator.
4. The NCRP recommends an annual EqD to localized area of the skin and hands of ______
1. UNDER. / OVER
2. Storage Devices
3. As Close To
- Scatter
4. 500 mSv (50 rem)
85
**REVIEW**
1. Radiation Shielding Categories:
2. _______- -Comes directly from the tube and moves without deflection toward a wall, door, viewing window, etc.
3. Results when x-rays pass through matter. Protons emerge from the matter in all direction: _____________
- Intensity compared to primary:
4. Generated in the x-ray tube and does not exit through the collimator_______
1. Primary, Secondary & Leakage
2. Primary Radiation
3. Scatter radiation
- Greatly Reduced
4. Leakage Radiation
86
**REVIEW**
1. A parameter used to reflect the units "radiation on" time is used in determining barrier shielding requirements.
2. _______ is a quantity that reflects structures that are struck by radiation for some fraction of work week
3. The _______ is used to modify the shielding requirement for a particular barrier by taking into account the fraction of the workweek that the space beyond the barrier is occupied.
4. If a region adjacent to a wall of an x-ray room is occupied by occupationally exposed individuals, that location is designated a _
1. Workload (W)
2. Use Factor
3. Occupancy Factor (T)
4. Controlled Area
87
**REVIEW**
1. A hallway or area adjacent to an x-ray room that is frequented by the general public is classified as an _______
2. For each wall, door, and other barrier in an x-ray room that is to provide protection against radiation, the product of _______ must be determined.
3. Caution Signs for Radiation must designate:
4. radiation workers can receive a larger equivalent dose than general public without altering the _________
1. Uncontrolled Area
2. W x U x T
(Workload x Use Factor x Occupancy Factor)
3. Signs designate:
Radiation Area
High Radiation Area
Very High Radiation Area
4. GSD (genetically significant dose)
88
1. If a radiographer stands 6 m away from an x-ray tube and receives an exposure rate dose of 4.0mGy/ hr, what will the exposure rate dose be if the same radiographer moves to stand at a position located 12 m from the x-ray tube?
1. 1 mGy/hr
INVERSE SQUARE LAW
Int 1 / Int 2 = Dist 2^2 / Dist 1 ^2
4 / x = 12 ^2 / 6 ^2
4 / x = 144 / 36
4 / x = 4 / 1 (SIMPLIFY)
4(x) = 4(1)
4(x) = 4
x = 1
