Show:
Ch. 2,5 & 8
Ch. 6,7 &10
Ch. 11,12 & 15
Ch. 16 &17
Ch. 22,28 & 29
100
Define an atom and a molecule?
Atom: smallest particle of an element that still posses the chemical properties. Molecule: two or more atoms chemically united
100
What conditions must exists for x-rays to be produced?
source of electrons, target material, high voltage and vacuum
100
What is the relationship between distance and density/IR exposure?
As distance increase, intensity decreases which causes a decrease in IR exposure
100
What elements comprise the majority of those found in the body?
Air, fat, muscle and bone
100
What are the 4 basic components of an intensifying screen?
Base, reflective layer, phosphor layer and protective coat
200
What is ionization
Process of adding or removing an electron from an atom
200
Define leakage radiation?
Any photons that escapes from the housing except at the port
200
What is the unit of measurement for x-ray quantity?
Roentgen
200
What type of grid has the lead strips running in one direction?
Linear grid
200
What is the differences between fluoroscences and phosphorescences?
Fluroescences is instantaneous emission whereas phosphorescences is a delayed emission
300
What is kerma?
The kinetic energy released per unit mass
300
Most of the electron energy in the x-ray tube is converted into what kind of energy?
Kinetic energy
300
What is backscatter?
Photons that deflect back toward the source, traveling in the opposite direction of the incident photon
300
When should a grid be used?
when a kVp is above 60 and body part thickness exceeds 10cm
300
What are the 3 methods of measuring resolution?
lp/ mm, line speed function and modulation transfer function
400
Name 3 types of tube support systems?
Over-head, floor to ceiling, and floor
400
What is the average keV of the primary beam as compared to the kilovoltage peak?
30-40 percent
400
What are the 2 interactions that have an impact on radiographic imaging?
Photoelectric and Compton
400
How does an off-level grid error occur?
When the tube is angled across the long axis of the grid strips
400
What 3 factors affect the power of intensifying screens?
phosphor size, phosphor layer thickness and phosphor concentration
500
What device in the x-ray circuit controls kvp? ma? time? rectification?
Autotransformer, filament transformer, timer circuit, # of diodes
500
What is filtration?
Is the process of eliminating undersirable low energy photons by the insertion of absorbing materials into the primary beam
500
What are the 2 factors that affect the amount of scatter produced?
kilovoltage and irradiated material
500
How does the air gap technique improve contrast?
By moving the patient away from the IR, which in return reduces the amount of scatter
500
How can shape distortion be used to an advantage?
As in a tangential view