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
