Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Principles Exam #1
| Question | Answer |
|---|---|
| The date that X-rays were discovered | November 8, 1895 |
| The person who discovered X-rays | Wilhelm Conrad Roentgen |
| The type of partially evacuated glass tube that was being used when X-rays were discovered | Hittorf-Crookes Tube |
| The term "radiation" simply means | energy emitted and transferred through space/matter |
| 3 types of ionizing radiation that can potentially cause biological changes in human tissue | x-rays, gamma rays, alpha/beta particles |
| X-rays are part of an energy spectrum of waves traveling through space all around us | electromagnetic spectrum |
| X-rays are considered what kind of radiation | man-made |
| gamma rays are known as what kind of radiation | natural |
| gamma rays are produced in what part of an atom | inside the nucleus |
| X-ray photons are produced in what part of an atom | outside the nucleus |
| tube converts about what percentage of the electrons accelerated across the tube into X-ray photons | 1/4-1/10 of 1% |
| Brems X-rays | Produce randon electrons (high-Low) breaking/slowing General and wide spectrum isotropic no ionization attracted by nucleus lose kinetic energy |
| Characteristic X-ray | must have less than 69.5 KVP ionization is unstable only 15% of X-rays outer shell fills in inner shell specific to the difference in binding electrons (characteristic cascade) |
| The direction of all X-rays produced in an X-ray tube | isotropic |
| electrons | have a mas of 9.1 X 10~3 KG and a negative charge and can travel at high speeds |
| X-ray photons | Have no mass and no charge and travel only at the speed of light |
| individual bundle of X-ray energy | photon or quantum |
| X-ray frequency and wavelength are | inversely proportional to each other |
| longer wavelength X-ray photons have | shorter/lower frequencies |
| The positive electrode/component of an X-ray tube is | Anode |
| Negative electrode/section of the tube is | Cathode |
| what is the diagnostic X-ray wavelength range | 0.1-1.0 A units |
| Basic function of Cathode | produce electrons |
| Basic function of Anode | produce X-ray photons |
| The filament of the X-ray tube is heated to boil electrons off of its surface by what process | Thermionic emission |
| During Thermionic emission electrons are accelerated across the tube to give them what | Kinetic Energy |
| The electrons sitting around the filament are known as the | electron cloud or space charge cloud |
| when electrons move across the X-ray tube they are known as | electron stream |
| The electron cloud will never move across the X-ray tube unless what | High KVP voltage is applied to them |
| 3 major components of an X-ray circuit are: | Power supply/high voltage generator X-ray tube X-ray control panel/console |
| Attenuation definition | a decrease in the # amount of X-ray photons passing through a patient or object being exposed to X-rays |
| 2 main physical processes that produce attenuation of the X-ray beam during an exposure | Absorption Scattered Radiation |
| 2 main patient attenuation factors that we can assess before making an exposure are: | patients size/thickness tissue/density |
| The greater the thickness of the patients tissue being exposed the greater the amount of | Attenuation that will be produced |
| The lower the density of the tissue being exposed the lower the | amount of attenuation that will be produced |
| The greater amount of attenuation that occurs to the X-ray beam as it passes through the patients tissues the ______________the density of the image area | Lower/whiter |
| "Real Time" viewing of the X-ray image on a TV or computer monitor is known as what? | Fluoroscopy |
| What is the function of the tube housing surrounding the X-ray tube | It absorbs isotropic radiation produced inside the tube and supports the tube and acts as a heat reservoir |
| X-ray photons travel through space or matter in the form of what | sine waves or electromagnetic waves |
| The term Bremsstrahlung means what | slowing/breaking |
| The term frequency applies to the what | wave characteristics of X-ray photons |
| What must be applied to an electron cloud in order for it to move across the X-ray tube | high voltage/energy as KVP (kilo volts peak) |
| An object that produces NO attenuation of the X-ray beam would produce what type of image | A totally black image or uniformly dark image there would be no differentiation because all photons hit the IR and the same density across the image |
| The wavelength of a X-ray photon is | inversely proportional to its energy |
| Primary function of the focusing cup in the X-ray tube | forces the electrons in the electron cloud to stay together in an electron stream. because it has a higher negative charge than the cloud |
| OID | object - to image receptor-distance |
| SOD | source - to object - distance |
| SID | Source - to image receptor - distance most used |
| SR | scatter radiation |
| scatter radiation | x-rays scattered back in the direction of the incident X-ray beam |
| PR | Primary radiation: what comes out of the tube |
| RR | after attenuation |
| what is the relationship between X-ray energy (KVp) to beam penetrability | Direct relationship KVp is the radiographic exposure or technique factor that controls X-ray beam penetrability. Higher KVp = more penetrability |
| whats the relationship between patient tissue density and the image density that tissue produces | opposites because X-rays are negative images |
| an area of radiographic film that is lighter/whiter than surrounding area means that lighter area has... | higher/increased tissue density higher/increased patient thickness |
| A black or dark area of radiographic image is produced when there is | very little attenuation of the primary X-ray beam |
| A radiographic cassette is used to hold | intensifying screens and X-ray film or imaging plate |
| resolution in radiology is measured in | pairs/mm |
| recorded detail | refers to the sharpness of the structural lines that can be seen in an X-ray image |
| In radiographic images what is considered to be the reciprocal or opposite of contrast | latitude |
| in radiographic images latitude is considered the opposite or reciprocal of what | contrast |
| in radiographic images contrast is usually defined as: | the differences between blacks and whites in the image |
| In radiographic images latitude is described as: | ability to recored the grey tones |
| Density definition | the amount of light transmitted to the observer of the image |
| Contrast definitions | described as the difference between density areas in an image |
| An individual density level in an image is know as | tone |
| in radiographic images a white or clear area represents what | a lack of density |
| Any radiographic image requires a minimum of how many different densities to produce an image | 2 |
| Low contrast is also known as | long scale contrast |
| Short scale contrast is also known as | high contrast |
| an X-ray image with mostly grey tones would have what kind of contrast | low contrast |
| CR | Central ray unless talking about a specific type or method of digital imaging |
| Higher contrast images are produced using what kind energy techniques | lower energy techniques |
| Lower contrast images are produced with what kind of techniques | Higher energy techniques |
| The contrast seen in the final radiographic image is composed of 2 components known as | image receptor contrast & subject contrast |
| The contrast inherent in the patient is controlled by 3 factors that include - | KVp, patient thickness and amount of SR produced |
| Higher KVp (energy) techniques produce what kind of attitude image | Wider latitude |
| Higher contrast images have what kind of latitude | narrow latitude |
| which type of contrast & latitude has less room for technique variations when making X-ray exposure | high contrast also known as low scale contrast |
| Why use "beam restriction" during an X-ray | to reduce exposure to patients and techs |
| Scatter Radiation definition | An X-ray photon that interacts with matter and changes direction SR |
| whats the major function of an intensifying screen | absorb X-ray photons Change X-ray photons to light to expose radiographic film |
| Grid function | absorbs SR to keep it off the IR |
| filtration function | to remove low energy photons and reduce patient dose |
| Collimator | has no direct function in the production of X-ray photons it is a variable aperture beam limiting device |
| Fog | decreases image contrast and hides info recorded in the image |
| intensity is known as | exposure rate |
| what material is most commonly used in diagnostic radiology to filter X-ray beam | Aluminum |
| SID is composed of 2 other distances | OID & SOD |
| scatter radiation is the primary source of radiation exposure to both | patient and healthcare personnel |
| 2 photographic properties of an X-ray image are | Density & Contrast |
| X-ray photons travel in | straight lines |
| 3 factors that affect/control the geometry of X-ray image formation include | Distance, Motion and FSS |
Created by:
1265731140
Popular Radiology sets