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
Intro Rad Pro week 3
Intro to Rad Protection week 3
| Question | Answer |
|---|---|
| Digital imaging techniques are always applied to | computed tomography (CT). ultrasound. magnetic resonance imaging. (All of the above.) |
| The latent image is formed on the____ for digital radiography. | radiation detector |
| Each matrix pixel represents_____ in digital fluorscopy. | atomic number and mass density |
| In digital radiography, the brightness of the image is determined by | pixel values |
| Digital imaging could only be developed after advances were made in | microprocessors. semiconductor memory. |
| Computed radiography developed in the 1970s with the use of ____ as the image receptor. | phosphor |
| Scanned projection radiography was developed as a complement to____. | computerized tomography. |
| What is the most recent development in digital radiography image receptors? | direct capture solid-state devices |
| Digital radiography first began to be used in clinical settings in the_____. | 1980s |
| Spatial resolution is improved with increased____ in digital radiography. | matrix size |
| The number of visible shades of gray in a digital image is determined by___. | bit depth |
| The dynamic range determines the degree of___ in the image | contrast resolution |
| _____ requires the largest matrix size. | Computed radiography |
| The typical matrix size for digital radiography is____. | 1024 X 1024 |
| Spatial resolution is determined by the ratio of____to____. | field of view, matrix size |
| Scanned projection radiography differs from conventional radiography in the lack of | scattered x-rays. |
| In scanned beam radiography the spatial resolution is determined by the | number of detectors. |
| The primary limitation of fanned beam radiography is | long scanning time. |
| Computed radiography utilizes____ for latent image formation. | photostimulable phosphor |
| Conventional x-ray tubes and cassettes are used with____ radiography systems. | computed |
| Detectors acquire info by | Scanning array detection |
| The window level controls | image density |
| The window width controls | image contrast |
| Resolution is controlled by ____ size. | Pixel |
| Detectors currently used in CR include all of the following except | capacitor plates |
| Digital radiography replaces | Traditional film |
| Silicon and selenium receptors are also known as | Flat panel detectors |
| Which type of system uses a a two-part process to convert incoming x-ray photons to an electronic digital signal | indirect conversion |
| During the two part conversion system a ___ converts light into an electronic digital signal | photodectector |
| During the two part conversion system a _____ converts x-ray photons to light | Scintillator |
| A photostimulable imaging plate includes a ___ layer | Phosphor, conductor, protective |
| DR cassettes are also know as | Filmless cassettes |
| The most common phosper use for computed radiography imaging plates is | barium fluorohalide bromides and iodides with europium activators |
| The active layer of the CR imaging plate is made of | phototimulable fluorohalides |
| The latent image is created by energy transfer during | photoeletric interactions |
| The latent image will lose about 25% of its energy in | 8 hours |
| The latent image is processed by a(n) | image reader device |
| The CR imaging plate is scanned by a(n) | Helium-neon laser beam |
| When the CR imaging plate is scanned the phosphors of the latent image release energy in the form of | Light |
| During CR imaging plate processing, the laser frees trapped electrons allowing them to return to a lower energy state. This process is known as. | photostimulated luminescence |
| Fluoro was developed so that radiologist could view ____ images | dynamic |
| What is the milliamperage used during fluoro | 5mA |
| The image intensifier improved fluoro by increasing image____. | brightness |
| With image intensification the light level is raised to ____ vision. | photopic |
| X-rays that exit the patient and enter the image intensifier first interact with the | input phosphor |
| The output phosphor of the image intensifier is composed of___. | zinc cadmium sulfide |
| The input phosphor converts___ to ___. | x-rays, light |
| The ___ in the image intensifier emits electrons when it is stimulated by light photons | photocathode |
| The number of light photons emitted withing the image intensifier is ___ to the amount of x-ray photons exiting the patient. | directly proportional |
| Electrons hit the ____ after exiting the anode. | output phosphor |
| The ___ is the product of the minification gain and the flux gain. | brightness gain |
| The ratio of x-rays incident on the input phosphor to light photons exiting the output phosphor is called ___ gain. | flux |
| The capability of an image intensifier to increase the illumination level of the image is called its. | brightness gain |
| An image intensifier tube is identified by the diameter of its | input phosphor |
| Brightness gain is typically in the range of___. | 5,000 - 30,000 |
| Fluoro for an air contrast barium enema is generally done at ___ kV. | 80-90 |
| Viewing the fluoro image in magnification mode increases | (all of the above) Contrast resolution, spatial resolution and patient dose |
| Automatic brightness control(ABC) maintains the brightness of the image by varying | kV and mA |
| The fluoro x-ray tube and image receptor are mounted on a | C arm |
| The carriage commonly support the | (all of the above) image intensifier, power drive controls, and spot film selector |
| During fluoro, the SOD cannot be less than ___ inches | 15 |
| The photocathode absorbs ___ and emits ____. | light photons, electrons |
| Electrostatic lenses are used to accelerate and focus | electrons |
| The primary ___ occurs from the acceleration and focusing of the electron beam. | brightness gain |
| The input screen is ____ in shape. | concave |
| The shape of the input screen helps to control | distortion |
| The photocathode is composed of ___ metals | photoemissive |
| Photoemissive materials absorb ____ and emit ___. | light photons, electrons |
| The greater the voltage supplied to the electrostatic lenses, the ___ the acceleration and the ___ the focal point to the input screen. | greater, closer |
| the most common solution for quantum mottle is to | increase the fluoro tube mA. |
| An electron that is described as being metastable: | Has higher energy than it should have |
| Doping of a photostimulable phosphor with Europium results in | More stimulable light emission |
| Photostimulable phosphor image receptors are effective because | Metastable states are produced |
| Photostimulable phosphor image receptors | Can be fogged by background radiation |
| To remove the image background radiation or a previous image, one should | Expose the image receptor to intense light |
| The slow-scan portion of the computed radiography reader | Is under mechanical control |
| Spatial resolution in computed radiography is principally determined by | laser beam diameter |
| The source of the stimulating light is: | The laser |
| How does the computed radiography reader maintain the laser beam as a circle | Beam-shaping optics |
| The x-ray capture element of a computed radiography imaging plate is the | BaFlBr (w/europrium) |
| An advantage of computed radiography over film/screen, regardless of the type of exam, is the relatively constant: | Image contrast |
| Which of the following is an advantage of CR over film/screen. | Fewer repeats |
| Digital radiography | Requires computer processing |
| A scanned projection radiograph | Is virtually scatter-free |
| The image receptor in CR is | BaFlCl |
| Which of the following is used as a radiation detector in a DR | Selenium (silicon) |
| The max frame acquisition rate in digital fluoro is about: | 30 frames per second |
| During digital fluoro | The x-ray beam is pulsed |
| How many video monitors are required for digital fluoro | Two |
| Interrogation time: | Is the time needed to switch on the x-ray tube |
| An advantage of digital imaging over conventional imaging is which of the following | postprocessing |
| The mask image is usually the: | Image just preceding contrast |
| A misregistration artifact | Occurs when a patient moves |
| Remasking | Can correct for patient motion |
| CR Computerized Radiography | Barium Fluorohalide with Europium (Cassette w/ IR) |
| Indirect DR (Digital Radiography) | Digital Radiography where photons are converted to light then to electrons |
| Indirect DR (Digital Radiography) | CsI or Gadolinium oxysulfide GdOS |
| Indirect DR (Digital Radiography) | Thin film transitor or amorphous silicon convert electrons captured to light |
| Direct DR | Involves no scintillating crystals |
| Direct DR | Uses amporphous Selenium as capture and coupling element |
| Minification times flux gain equals | Brightness gain |
Created by:
Joker71
Popular Radiology sets