RADBIO Flashcards
- 1 meter = ______ Centimeters = ______ Inches
- Centermeters to Inches:
- 1 Kilogram = ____ lbs
- 1 meter = 100 centimeter = 39.37in
- 2.54cm = 1in
- 1kg = 2.2lbs
- Farenheit to Celcius:
- Celcius to Farenheit:
- Law of Conservation of Energy:
- Smallest subdivision of element:
- 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
- Proton vs Neutron Charge in Nucleus:
- Z =
- A =
- Where are electrons?
- Their Charge?
- Proton = Positive / Neutron = Neutral
- Anatomic Number (Number of Protons in Nucleus)
- Anatomical Mass (Sum of Protons)
- Orbital shell outside nucleus
- Negative
- Closer electrons is to nucleus, the ______ binding energy
- What is valence?
- Formula to calculate electron limit:
- Stronger
- Number electrons in outter most shell
- 2n2 (n is number of shells counting from nucleus, K-Shell being 1)
- What are 4 conditions needed to produce x-ray
- 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)
- What is a space charge?
- Filaments are located:
- How is electron energy converted to kinetic?
- What material is Anode? Why?
- Released Electrons in tiny cloud around filament wires
- Cathode
- Accelerated electrons must be stoped/slowed down
- Tungsten b/c high atomic # & high melting point
- Interactions That Occur At The Anode:
- Compare the 2:
- 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
- X-Ray is what type of radiation?
- Difference between X-Ray & Gamma Rays?
- X-Ray Frequency Means:
- Desired
- Frequency measured in:
- Electromagnetic
- ORIGIN: XRay outside Nucleus, Gamma Ray in Nucleus
- Number times per second electric & magnetic field regenerate themselves
- DESIRED: High Frequency - Hertz (Hz)
- X-Ray Wavelength Means:
- Desired:
- Unit: - Relation between Wavelength & Frequency
- X-Ray Beam is Described in terms of _______ & ______
- Distance between peaks / distance between regenerations
- SHORT Wavelength
- Angston
- SHORT Wavelength
- INVERSE (As frequency increases, wave length decreases)
- Quality & Quantity
- Quality of Beam Means:
- Controlling Factor:
- Quantity of Beam Means:
- Controlling Factor:
- Primary vs Remnant Beam:
- 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
- Explain Inverse Square Law
- Formula:
- When Distance Doubled =
- 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
Properties of X-Ray Photons:
A. Travels In:
B. Penetrating Ability:
C. Charge:
D. Wavelengths:
E. Travel Speed:
F: Effects:
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
- Compton Interaction
- AKA:
- Occurs: - Photoelectric Absorption
- Occurs: - Coherent Scatter
- AKA:
- Occurs In:
- 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
- Define Attenuation
- NRCP Stands For
- What is their function?
- Types of Doses:
- 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
- Absorbed Dose
- What Is It:
- SI Unit:
- Conversion: - Dose Equivalent
- What Is It:
- SI Unit:
- Conversion:
- 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
- Exposure
- What Is It:
- SI Unit:
- Measured With: - Effective Dose:
- What Is It:
- SI Unit:
- Conversion:
- 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
- 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:
- 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
- _______ - 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?
- Deterministic
- Stotachtic
- Determenistic = Threshold
Stotastic = Probabilty (no threshold) - Deterministic = days
- Stotastic = months/years later
- What dose-response imaged?
- _______ - Radiation dose is doubles, response to radiation doubled (directly proportional)
- ________- Responses increase rapidly or taper off as dose increases
- LINEAR, NON-THRESHOLD
- Linear
- Non-Linear
- What dose-response imaged?
- ______ - Takes certain dose before response will manifest
- Acute Radiation Syndrome Occurs When:
Linear Threshold
- Threshold
- Whole Body Dose must be greater than 1 sievert
- What dose-response imaged?
- ______ - any dose has potential to cause response / no safe dose
- What affect radiosensitivity the most?
- non-linear, non-threshold
- non-threshold
- Cell Maturity / Rate of Division
- What dose-response curve imaged?
- More Radiosensitive Cells Are:
- LET stands for:
- Nonlinear - Nonthreshold
- Young / Rapidly Dividing
Ex: Fetus - Linear Energy Transfer
- What is LET?
- What is LET relation to RBE?
- What has high LET?
- What has low LET?
- 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
- What does RBE stand for?
- What is RBE?
- What affects RBE?
- Relative Biological Damage
- Describes capability of various radiation to produce biological effect
- Type of radiation dose rate and type of tissue
- 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^
- High-Risk Exams For Women. (3)
- High-Risk Exams For Men. (3)
- Special Concerns For Pediatrics Include:
- B.E, L-Spine, IVU
- Hip/Pelvis, L-Spine, IVU
- Biological Effects, Reduce number of views, do NOT do comparison views
- Difference between high doses & low doses to cell survival:
- how can cells that have been damaged by sublethal doses of radiation be repaired?
- What is LD50?
- What is LD50/60?
- What is the number for LD50/60?
- High = kills, Low = damages
- Enzymes
- LD50 = dose whole body radiation that will kill 50% exposed population
- LD50/60 = 50% of exposed individuals will die within 60 days
- LD50/60 = Whole Body Dose of 3.5 Sv
- Oxygen & Cell Sensitivity Relation:
- Why?
- What is OER
- OER Relation to LET
- Well-Oxygenized Cells are MORE sensitive to radiation
- Oxygen creates additional free radicals which increase damage to cells
- Oxygen Enhancement Ratio - ratio of hypoxic doses to oxygenated doses to achieve same biological affect
- Low LET = OER 3
Fast Nuetrons = OER 1.5
High LET = OER 1
- What LET is X-Ray? OER?
- Somatic Effects Refer To:
- What are germ cells?
- Includes:
- Low LET, OER 3
- All non-reproductive cells or tissues
- Reproductive cells or tissue
- Oogonium & spermtogonium
- Mitosis process of _______
- Phases Consist of: (names only)
- Most radiosensitive phase:
- What forms/occurs & results:
- SOMATIC Cell Division
- Prophase, Metaphase Anaphase, Telophase, Interphase
- Metaphase
- 2 Parent Cell Divide
- Form 2 Identical Daughter Cells
-23 Pair Somatic Cells / 46 Chromosomes
- Germ cells undergo what division?
- Same or different than somatic cells? how?
- What is Result of Meiosis?
- Haploid vs Diploid?
- Meiosis
- Same at somatic except it goes through another phase without DNA duplication)
- Four Identical Granddaughter Cells
-23 Chromosomes - Diploid: 23 pairs (46 chromosomes)
Haploid: 23 chromosomes
- DNA located in:
- RNA located:
- Bulk of Cell Made of:
- Energy for cell:
- Nucleus
- Mostly Nucleus but also nucleolous
- Cytoplasm
- Mitochandria
- What are protein synthesizers?
- Target molecule for radiobiology
- Direct vs Indirect Effect:
- Which occurs more?
- Ribosomes
- DNA
- Direct: Radiation strikes DNA directly
Indirect: Radiation strikes water molecule which releases free radicals that then strike DNA - Indirect
- Short Term Effect Occur:
- AKA
- Examples: - Long Term Effects Occur:
- AKA:
- Examples:
- biological effects occur shortly after an exposure
- Early Effects
- Skin Erythema & Desquamation (peeling) - biological effects dont occur for years after exposure
- Late Effects
- Skin Cancer
- Acute Effect
- Occurs:
- Example: - Chronic Effect:
- Occurs:
- Examples:
- Sudden Onset
- Large Radiation Exposure
- Acute Radiation Syndrom - Occurs over time / prolonged / Late in life
- Low levels radiation over long period time
- Cancer, Leukemia