Notes Flashcards
Oil based barium is for
Bowel obstructions/bowel performations
Barium sulfate is used for
Sepsis
Positive contrast agent
Barium/iodine (higher atomic number)
Negative contrast agent:
Air/gas (lower atomic number)
What does threshold mean ?
Safe up to a certain part
Non threshold means?
No dose is a safe dose
Linear means ?
Directly proportional
Non linear means :
Not directly proportional
Example of non linear threshold
Cataracts
Example of linear non threshold
Thyroid cancer
Early tissue reaction
Minutes, hours, days
Late effects
Cancer (stochastic) random
What is radiolysis ?
Free radicals with water
What is target theory ?
Radiation hits cell so many times it will die
Most sensitive phase of mitosis?
Metaphase
Difference of fractionation and protraction?
Fractionated: large dose broken up
Protracted: small dose over time
Bremstrahlung
Nucleus
If the kvp is below 70 all interactions are
Brems
If the kvp is above 70 what % are characteristic and brems ?
85% brems
15% charactersitic
What is leakage radiation?
Never deals with body
What does leakage radiation have to stay below ?
100mR @ 1m
Body interaction with coherent scatter
Excited cell and leaves, no interaction, and non ionizing
Compton body interaction
Scatter as occupational dose, outer shell, recoil electron, and scatter electron
Photoelectric effect
Inner shell
What is radiopaque?
Can’t see through example (iodine)
What is radiolucent ?
Can see through, examples sponges
Sizes of smaller/larger filaments
Smaller: .1 to .5
Larger: .4 to .2
Remnant exit radiation comes out of?
The patient
What is the input phosphor?
Concave in shape, cesium iodide turns X-rays to light
What is a photocathode ?
Concave cesium antimony (light to electrons)
Electrostatic lenses
Electrons stagger cone electrons pulled up, kv accelerates 30-35
What is vignetting
Unsharpness around the edges
Define mag mode:
Shows a better detailed picture
Does mag mode increase patient dose or decrease patient dose?
Increase
Lead Bucky slot cover and lead curtains have what amount of lead ?
0.25 mm lead
Is density more black and white or gray?
Overall blackness of an image
Is contrast more black and white or gray?
Gray
If you increase mas and density you
Produce more photons
True/false
Kvp can affect quantity and quality
True
If you increase kvp what happens to exposure
Increase exposure
If you increase kvp you increase scatter which can cause what?
fog
If you increase kvp, what happens to contrast
Decreases
If grid ratio increases, photons reaching the IR increases or decreases
Decreases
If you increase the field of view, what happened to the collimating ?
Decrease collimation
If you decrease field of view what happens to collimation?
Increase collimation
Additive conditions
Increase the contrast, more is getting absorbed
Occupation worker effective dose limit
50mSv
Quarterly effective dose limit for an occupational worker ?
12.5 mSv
Cumulative occupational worker (whole body)
10 mSv X age in years
NCRP #116 recommendation for annual dose for a student?
1mSv
NCRP #116 pregnant tech/fetus
Pregnant tech is 5 mSv per gestation/ 0.50 per month
Average occupational exposer annual?
1mSv-5mSv
Annual dose for skin/organs
200 mSv
Annual dose for eyes ?
150mSv
General public dose for skin/organs?
1/10th occupational dose 5 mSv infrequent
General public dose for eyes ?
1mSv for frequent
Fluoro timer is for ?
5 minutes
Fluoro exposure to patient at tabletop
Not > 10R/min total
Leakage radiation from tube housing
100mR/hr -1 meter from tube
Source table distance fixed Fluoro tube
38 cm or 15 inches
Source table mobile fixed Fluoro tube
30 cm or 12 inches
sID indicator tape measure is accurate to
2% sid indicated at 40 inches
Collimation accuracy has to be
2% SID
Reproducibility of exposure
5%
Linearity
10% variability
Kvp accuracy
5%
Filtration if it’s below 50 kvp
0.5 mm aluminum minimum
Filtration 50-70 kvp
1.5 mm aluminum
Filtration above 70 kvp
2.5 mm aluminum (0.5mm inherent plus 2 mm added)
Portable cord must extend
6 feet; stand 90 degrees to scattering object
Protective shielding falls under which NCRP?
NCRP 102
Primary barrier
1/16th PB
Secondary barrier
1/32nd PB
Protection from scatter and leakage radiation must have how much overlap?
1/2 inch
Bucky slot cover/curtain must have
0.25 lead equivalent
Aprons must have
0.25 mm lead equivalent
Glasses must have
.35 mm PB
Amount of time by a given individual
Occupancy Factor
Occupancy factor for controlled areas abs uncontrolled
Control: radiation workers exposure rate is < 100mR week
Uncontrolled: occupied by anyone exposure rate 10 mR per week
Amount of time the tube is energized
Use factor
Film badge
Detects as low as 0.1 mSv to as high as 5000 mSv: contains films, filters, aluminum, copper, tin, permanent record use for 1 month
TLD
Detects as low as 0.05 mSv contains lithium fluoride crystals, filter: spectrum chip, written record, use for up to 3 months
OSL
Detects 0.01 mSv to 10 mSv contains aluminum oxide, filters: aluminum, tin, copper, permanent record, use for up to 1 year
Pocket dosimeter
Detects as low as 0.03 mSv; rely on the ability of ionizing radiation to ionize a gas wh thing a sealed chamber resulting in changes of electrodes; pencil shaped ionization chamber no permanent record and immediate reading
Point at which a response or reaction to an increasing stimulation first occurs, below a certain radiation level no biological effects observed
Threshold
Any radiation dose is capable of producing a biological effect
Nonthreshold
Dose and response are directly proportional
Linear
Dose and response are directly proportional
Linear
Dose and response indirectly proportional
Nonlinear
Occurs within minutes, hours, days, weeks, from higher doses nausea, fatigue, erythema, epilation, blood disorders, intestinal disorders, fever
Early tissue reactions
Months or years after, cancer, catsractogenesis
Late tissue reactions
Cancer, genetic effects
Stochastic
Bone marrow destruction, reduction or RBC, WBC, and platelets
Linear, threshold
LET
Average energy deposited by radiation, as LET increases, biological damage increases
Alpha has high LET, X-ray and gamma have low LET true or false
tRue
RBE
Radiation of different levels produces a particular biological effect, RBE and LET see directly related
Oxygen effect, more sensitive with oxygen less sensitive without oxygen OER for human tissues has a maximum of 3.0
OER
Equal dose of radiation that is delivered with time interval separations
Fractionation
Radiation dose delivered continuously but at lower dose rate
Protraction
Double strand contains genetic information
DNA
A and G
Purines
C and T
Prymidines
A and T bond and c and G bond in DNA true or false
True
Single strand uracil links with adenine
rNa
Parent cell divides to form 2 daughter cells
Mitosis
Germ cell division
Meiosis
In pregnancy what is most sensitive but least radio resistant
First trimester
Law if bergonie and tribondeau
Immature cells are more sensitive, sensitivity increases with mitotic activity, sensitivity frs teases with increased specialization.
Least sensitive to most sensitive
Nerve, muscle, and lymphocyte
Step down delivers
Ma
Transformers
Start at ac current rectifier changes them to direct current
Primary side (low voltage) step up changes to kilo voltage
Auto transformer
Source for voltage in the generator
Auto transformer
Step down transformer mutual induction decrease voltage increase amperage
Filament
Only 1% ripple most efficient
High frequency
Controls quantity no effect on quality
Milliampere seconds
Controls quality affects quantity
Kilovoltage
Res ipsa loquitur
The thing speaks for itself
Respondeat superior
Let the master answer
ARRT standards of ethics is composed of
Preamble, statement of purpose, code of ethics, rules of ethics, administrative procedures
How many cervical bones are there ?
7
How to control voluntary motion?
Clear communication, sandbags, sponges, tape, short exposure, etc
When it comes to shielding if gonads are in how many centimeters of primary beam?
5 cm
Population with sthenic body?
50%
Population with hyposthenic?
35%
Population with asthenic body habits ?
10%
Population with hypersthenic ?
5%
Any plane parallel to MSP is called a
Sagittal plane
Divides the body into superior and inferior portions
Transverse plane
Central shaft is called
Diaphysis
Located at both ends of the diaphysis
Epiphysis
Femur and humerus are what kind of bone ?
Long bones
Wrist and ankle bones are what kind of bone?
Short bone
Ribs and scapular are what kinda of bones
Flat bones
Vertebrae sesamoids are what kind of bones
Irregular bones
Fibrous(synarthroses)
Immovable (skull sutures)
Cartilagenous (amphiarthroses)
Slightly movable (pubic symphasis)
Synovial(diarthroses)
Freely movable
Hinge joint:
Motion in one plane (elbow)
Pivot:
Rotary moving on ring rotated around axis (radioulnar articulation)
Concavo convex allowing flexion extension adduction and abduction
Saddle (thumb)
Movement in infinite number of axis
Ball and socket (hip/shoulder)
Gliding movement
Gliding (ankle wrist )
Two direction right angles to each other
Condyloid (radioulnar joint)
Not involving any angular rotary motion and is the easiest of movement
Gliding
How many thoracic bones ?
12
How many lumber bones?
5
How many sacral bones
5
How many coccygeal bones
4/5
Exaggerated lumbar concavity?
Lordosis
Lateral curvature of any region
Scoliosis
Exaggerated convexity in thoracic region
Kyphosis
Horseshoe shaped bile and pancreatic secretions are added to the small intestine
Duodenum
Greatest amount of absorption in small intestine ?
Jejunum
Connects with the small intestine is 2.5 meters long ?
Ileum
Approximately 1.5 m long?
Large intestine
Part of colon from cecum to the hepatic flexure
Ascending
From hepatic flexure to the splenic flexure
Transverse
From splenic flexure to the level of the pelvic bone on the left side of the body
Descending
S shaped curve in the colon
Sigmoid
From sigmoid colon down to the pelvic diaphragm
Rectum
How many centimeters is the anus
3 cm
Partial loss of continuity in a joint
Subluxation
Central ray for a PA hand ?
Perpendicular to the 3rd MCP joint
Central ray for oblique hand
Perpendicular to the third MCP joint
Central ray for a lateral hand
Perpendicular to second MCP joint
Up to a certain point ?
Threshold
No dose is a safe dose
Non threshold
Is directly proportional linear or non linear ?
Linear
Not directly proportional is linear or non linear ?
Non linear
If kvp is below 70 what is it ?
Brem
Above 70 kvp % of brem and characteristic ?
85 brem
15 characteristic
Body interactions include
Coherent and Compton
Higher attenuation higher absorption and lower transmission to IR
Higher atomic number
Lower attenuation lower absorption higher transmission to IR
Lower atomic number
Lower atomic number shows what kinda image
Darker image
Inner shell happens in what kind of interaction
Photoelectric
Anode is made of ?
Tungsten, high melting point
True or false KVP only effects quality
False; affects both quality and quantity
More shades of gray
Bit depth
Increases spatial resolution of image
Modulation transfer function
Window level controls?
Brightness
Window width controls
Contrast
Many shades of gray ?
Long scale
Long scale is also known as
Wide
Long scale shows
Low contrast, high KVP example is chest X-RAY
Short scale
High contrast narrow more black and white, narrow latitude examples is hand and foot X-rays
Increasing bit depth shows
More gray
SI Unit
Sievert and gray
Another word for sievert
REM
Another word for gray ?
RaD
If you increase mas what does that do to patient ?
Increases dose to patient
Biological effectiveness of radiation
Sievert
Xrays are weighed at
1
Alpha particles are weighed at
20
Coulombs per kilogram
Air kerma
Radioactivity
Becqueral
Less resistant (most sensitive)
Wbc fetus lumphocyte
Mature cells radiosensitive or no
Decrease radio sensitivity
Immature cells are sensitive or not
Sensitive
Cell division sensitive or not.
Sensitive
Least sensitive cells
Nerve, muscle, stem, lymphocyte
If a cell has more oxygen are they more or less sensitive ?
More sensitive
RBE and LET directly or indirectly proportional?
Directly proportional
LET low energy or high energy?
Low energy
Most sensitive cell division phase?
Metaphase
Cell division
Mitosis
Germ cells
Meiosis
Inverse square law is for
Intensity
Direct square law is for
Density
Fixed
38 cm or 15 inches
Mobile
30 cm or 12 inches
Portable cord
6 feet long
Lead apron for Fluoro
.5 mm lead
Lead apron for just xray
.25 mm lead
Lead needed for gloves
.25 mm lead
Thyroid shield lead
.5 mm
Eyeglass
.35 mm lead
Shielding minimum lead equivalent
NCRP 102
Source of KVP; primary determine amount of voltage
Auto transformer
Secondary side voltage becomes kilovoltage
Step up transformer
Step down transformer adjust current sent to filament
Filament transformer
Primary side how long duration of image seconds time
Exposure timer
Timer that is most accurate
Electronic timer
Using higher frequency
Creates more consistent image
How many bones in cervical neck
7 bones
Involuntary motion is controlled with
Short exposure
Equivalent dose
The product of absorbed dose X radiation weighing factor
Lower uo is at ion radiation such as X-rays and gamma rays have
Lower LET
Effective dose measurement
Sievert
Natural background radiation
48% largest source is radon
Primary radiation is
Radiation exiting the X-ray tube
Heterogenous beams
X-ray beam that contains photons of many different energies
Incoming photon strikes a loosely bound outer shell electron
Compton interaction
Photon has been completely absorbed
Photolelectric interaction
Incoming X-ray photon strikes a K shell electron energy of X-ray photon is transferred to electron
Photoelectric interaction
Perpendicular plates forms
Superior part of nasal septum
Spinal cord enters here to attach to brain stem
Foremen magnum
Large air space
Maxillary sinus
Upper bridge of nose
Nasal bones
Clavicle articulated with the manubrium at the
Eternal end
Clavicle articulates with the scapula at the
Lateral end
Lateral articulates with the radius expanded area just superior is call the
Lateral epicondyle
Medial articulates with the ulna expanded area just superior is called
Medial epicondyle
Proximal row of wrist bones
Scaphoid lunate triqueteum and pisiform
Distal row of wrist bones
Trapezium trapezoid capitate and hamate
Greater sciatic notch
Located beneath the articulates surface of hip bone
Shows adaptations related to functions as a birth canal, wide outlet, angle of the pubic arch is obtuse
Female pelvis
Shows adaptations that contribute to power and speed, heart shaped outlet, and angle of the pubic arch is acute
Make pelvis
Located beneath the talus
Calcaneus
Located in front of the talus on the medial side; articulates with three cunieform bones distally
Navicular
Lies along the lateral border of the navicular bone
Cuboid
Afferent neurons carry the sensory information to
CNS
Efferent neutrons carry the motor information away from the
CNS
How long is the spinal cord in centimeter
45.8 CM
Coordinates balance and equilibrium
Cerebellum
Bulb on the spinal cord located inside the foremen magnum
Medulla oblongata
Ropelike mass of white fibers connects the halves of the cerebellum
Pons
Membrous coverings of the brain and spinal cord
Meninges
Heart is located here
Mediastinum
How long is a cardiac cycle ?
0.8 seconds
output photons/ # input photons
Flux gain formula
Input diameter2/
Output diameter 2
Minification gain
Flux gain X minification gain
Total brightness formula
Concave, cesium iodide
Input phosphor
Concave, cesium antimony
Photocathode
Low voltage (25-35 KV)
Electrostatic lenses
Accelerates electrons
Anode
Zinc cadmium sulfide
Output phosphor
Protective curtain needs how much lead
.25
Bucky slot requires how much lead?
.25 mm PB
Total filtration requires how much aluminum
2.5 mm AL
OID + SOD
SID
SID - SOD
OID
SID - OID
SOD
Grid conversion formula
mAS1
mAS2 = GCF1
GCF 2
Which photon tissue interaction makes radiography possible because of its creation of contrast?
Photoelectric
Unit of radiation absorbed in air is the
Gy a
The unit of radioactivity is the
Becquerel
The unit of effective dose is the
Sievert
Medical X-rays are an example of
Artificially produced radiation
Cataractogenesis doesn’t not occur at low levels of radiation exposure; it is best expressed by which if the following dose response relationships
Threshold
Increased dose equals increase probability of effects best describes
Stochastic
The minimum source to skin distance for fixed Fluoro is
15 inches
The blood count is depressed after a whole body dose equivalent of at least how many rads
0.25 sv
The most common effect from exposure to ionizing radiation is
Nothing
Xrays may remove electrons from atoms in the body by a process called
Ionization
Ionization may cause
Unstable atoms
Damage to the cell being irritated is called
Somatic
The annual effective dose per person from natural background radiation is approximately
3.0 mSV
Lifetime accumulated occupational dose
Cumulative effective dose
Photon cell interactions occur
By chance
Calipers are used to measure
Patient part thickness
The smallest particle of an element
Atom
Atomic mass is the
Number of protons plus neutrons
Xrays travel as bundles of energy called
Photons
The height of a sine wave is called
Amplitude
The transformer that operates on the principle of self induction is the
Auto transformer
To ensure consistency of radiographic quality from one exposure to the next what device may be used
AEC
An X-ray machine that uses a continually decreasing mA for the shortest times possible is
Falling load generator
Devices in the X-ray circuit that operate in the principle of mutual induction are called
Transformers
The high voltage section of the X-ray circuit makes use of what type of transformer
Step up
The device in the X-ray cutout that changes AC TO DC is the
Rectifier
What type of current is required for proper operation of the X-ray tube
Direct
The focusing cup is located at the
Cathode
Interaction that produces X-ray at the anode as a result of outer shell electron filling holes in the k shell
Characteristic
In digital flouro the image should be viewed in a ?
High resolution monitor
Lightness and darkness of the image in computer radiography may be adjusted by
Adjusting the window level
Self induction occurs in
Auto transformer
Mutual induction occurs in the
Step up and step down transformer
The electricity provided to the radiology department
60HZ alternating current
The electricity provided to the radiology department operate at
120 pulses per second
A variable transformer that is used to select kvp for the X-ray circuit is the
Auto transformer
A transformer that has more turns in the secondary coil that in the primary coil is called
Step up transformer
Transformer used to boost voltage to kilovoltage levels called
Step up transformer
Voltage coming to the X-ray machine is kept constant through the use of an
Line voltage compensator
A step down transformer
Steps down voltage
Thermionic emission occur
Cathode
Which device is prereading
Kvp meter
Device reduce voltage and provides current to produce an electron cloud or space charge at the filament
Step down transformer
Device is electronic with a setting as low as 0.001
Timer
What changes AC to DC
Rectifier
Which is surrounded by a negatively charged focusing cup
Filament
Solid state silicon based diodes
Rectifier
What regulates the duration of X-ray production
Timer
What is located in the X-ray circuit between the high voltage transformer and the X-ray tube
Rectifier
What Measures tube current
MA meter
What device spins at 10,000- 12000 RPM
Anode
What device uses maximum heat storage ability of the tube to deliver mas
Falling load generator
What is the source of brenstrahmlung and characteristic rays
Anode
What device increases voltage approximately 509 times
Step up transformer
What is the most commonly used AEC
Ionization chamber
What device always delivers the shortest exposure time possible
Falling load generator
What device is turned by a rotor
Anode
Which of the following is located between the patient and the image receptor
Ionization chamber
The filament is kept warm by
A stay by current from the tjme the X-ray machine is turned on
Activating the rotor
Reduces tube life
The process of thermionic emission causes
Electrons to boil off the filament
The force with which the electron steam passes from cathode to anode is a result of … passing through the X-ray tube
Kilovoltage
Heat is produced in the X-ray tube as
Electrons interact with the target material
Most of the energy conversion in the X-ray tube produces
Heat
Xrays are produces as incident electrons are slowed going past the nuclei of target atoms by a process called
Bremsstrahlung
Xrays are produced as incident electrons collide with inner shell electrons in target atoms by a process called
Characteristic
What percentage of energy in the X-ray tube is converted to X-rays
1%
X-ray emission spectrum consists of
Discrete spectrum (characteristic) and continuous (brems)
Primary purpose of filtration
Radiation protection
Total filtration not less than
2.5 mm aluminum equivalent
Primary grid used in diagnostic imaging
Focused
Receptor exposure may be defined as
Dose area product
The radio graphic image is for
Ed by
Exit rays striking the image receptor
Primary controlling factors of receptor exposure are
Mas and Sid
Relationship between mas and receptor exposure
Receptor exposure is directly proportional
Receptor exposure is formally called
Density
MAS directly control
The quantity of X-rays produced at the anode
Relationship between kvp and receptor exposure may be described as
Direct although not proportional
The 15% rule states that
Receptor exposure may be halved by decreasing kvp by 15%
Governs the relationship between SId and receptor exposure
Inverse square law
If SId is doubled what may be said about the receptor exposure
Receptor exposure is reduced to one fourth
If SId is reduced by one half what must be done to mas to maintain a constant receptor exposure
Reduce mas to one fourth it’s original value
Which of the following describes the relationship between receptor exposure and the use of grids
Grids reduce receptor exposure unless mas are increased to compensate
The use of filtration
Has little effect on receptor exposure because a X-rays removed from beam are not image producing rays
As beam restriction increases
Receptor exposure decreases
The fiction of contrast is to
Make detail visible
Lower spatial resolution may be cause by what factors
Wide pixel pitch
Converts X-ray energy to light energy
Input phosphor
Coverts light every to electron energy
Photocathode
Converts electron energy T light energy for viewing
Output phosphor
Product of flux gain and minufcation gain
Total brightness gain
The ability to do work
Energy
Energy if position
Potential energy
Energy of motion
Kinetic energy
Energy that is emitted and transferred through matter
Electromagnetic energyy
Electromagnetic radiation that is able to remove an electron from an atom
Ionizing radiation
Removal of an electron from an atom
Ionization
Number of protons plus number of neutrons represented by the letter a
Atomic mass
Number of protons in nucleus: letter Z
Atomic number if an atom
Atoms with the same number of protons but with a different number of neutrons
Isotopes
X-ray bean inversely proportional to the square of the distance between the source of the X-rays and the object
Inverse square law
Matter cannot be created or destroyed only changed in form
Law of conservation of matter
Energy cannot be created or destroyed only changed in form
Law of converse ration of energy
Material that allow the free flow of electrons
Conductor
Object that prohibits the flow of electrons
Insulator
Material that may act as an insulator or conductor under different conditions
Semiconductor
Voltage in the circuit is equal to the current X resistance
Ohm’s Law
What is the source of brem and characteristic tags
Anode
The force with which the electron steam passes from cathode to anode is a result of … passing through the tube
Kilovoltage
Xrays are produced as electron are slowed going past the nuclei of target atoms by a process called
Brems
What percentage of energy is in the X-ray tube is converted to X-rays
1%
Exposure linearity must be accurate to withi
10%
Exposure reproducibility must be accurate to within
5%
Test that measures the accuracy of adjacent ma stations
Exposure linearity
Test that measures the accuracy of successive exposures
Exposure reproducibility
Up to a certain point
Threshold
No dose is a safe one
Non threshold
Brem or characteristic in the nucleus
Brem
Excited the cell and leaves no interaction non ionizing
Coherent
Procedure order
Endoscopy, urinary, biliary, CT, lower GI, Upper GI
What is a fomite
Object that has been in contact with a pathogen and susceptible host
What is a vector
Animal or insect transfers pathogen to human
Droplets and shat that are able to remain suspended in air for extended periods of time
Airborne transmission.
Transmitted primarily by coughs sneezes or other methods of spraying into a nearby host
Droplet transmission
Transmitted primarily by contaminated items such as food water medication device and equipment
Common vehicle transmission.
Arteries used for pulse
Carotid, radial
Blood pressure
Systolic/ diastolic
Pumping action of heart
Systolic pressure
Heart at rest measured
Dyastolic
Oxygen flow rate
3-5 liters a minute
Atoning number of 53
Iodine
Atomic number of 56
Barium
Upper GI and esophagram is barium mixed with
cold water
Barium enema is mixed with
Really warm water 100 F
