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PRI-II
CR & DR
| Question | Answer |
|---|---|
| Two types of digital imaging: | CR & DR |
| CR imaging is ________ based: | Cassette |
| CR imaging can be _______ or _______: | fixed or portable |
| The most common type of CR imaging is ________: | Portable |
| You can use existing XRay equipment with : | CR imaging |
| A CR cassette uses an ____ ________ instead of film: | IP plate |
| _________ alters the regions viewed on the displayed image and removes white/unexposed edges: | Cropping |
| _______ reduces veil glare by removing the white edges: | Background removal |
| _______ ____ sets the midpoint brightness level: | Window level |
| Increasing window level does what to brightness: | Increases |
| ______ _____ adjusts the number of shades of gray displayed on the monitor: | Window width |
| Narrower window width has ______ grays and _____ contrast: | Fewer, higher |
| Wider window width has ______ contrast and ______ grays: | lower, more |
| ________ __________ alters pixel values to increase contrast: | Contrast enhancement |
| ________ suppresses noise and lowers contrast, but degrades spatial resolution: | Smoothing |
| ________ removes superimposing structures: | Subtraction |
| _______ _______ is used for full leg or spine studies by putting the entire length of study on one image: | Image stitching |
| _____ receives, stores, distributes and displays images: | PACS |
| What does PACS stand for: | Picture Archiving communications system |
| What does DICOM stand for: | Digital imaging and communications in Medicine |
| ______ is the communication standard for information sharing between PACS and imaging modalities: | DICOM |
| HL7 stands for: | Health level standard 7 |
| ____ is the communication standard for medical information: | HL7 |
| What does HIS stand for: | Hospital information system |
| What does RIS stand for: | Radiology information system |
| Ability of IR (direct conversion), smaller helium neon laser, smaller pixels, larger matrix for given fov, increased sampling frequency, decreased sampling pitch, decreased pixel pitch, increased pixel density contribute to ________ _________ _______: | Increased spatial resolution |
| Contrast resolution is effected by _____ ___ _____: | Pixel bit depth |
| Direct digital imaing receptors can be _________ or _______ based: | Cassetteless or cassette |
| Three types of digital imaging receptors: | Direct conversion, indirect conversion & CCD |
| CCD (Charge couple device is an ________ process: | Indirect |
| DR is a one step process, it combines which two processes: | Image capture & image readout |
| DR detectors receive exit radiation and converts the varying x-ray intensities into _______ electronic signals for ditizing: | proportional |
| _________ uses a solid state IR, active matrix array of electronic components, converts x-ray photons into electrical charges that are temporarily stored for readout: | Flat panel detectors |
| ______ ______ detectors signal storage, readout & digitizing components are built into this type of detector: | flat panel |
| ________ ________ detectors have the following layers; x-ray converter, TFT & glass substrate: | Flat panel detectors |
| _____ is divided into DEL and each has a capacitor to store electrical charges and a switching transistor for readout: | TFT |
| TFT stands for: | Thin film transistor |
| List the 2 types of DR capture: | Indirect & direct |
| _________ capture is when x-ray photons are converted to light and then electrical charges: | Indirect |
| The scintillator layer of indirect conversion flat panels are made of _____ ______ or ______ _______: | Cesium iodide or gadolinium oxysulfide |
| Cesium iodide are _________ columnar and provide _____ spatial resolution: | Structured, higher |
| Why does cesium iodide provide higher spatial resolution: | Reduced light spread |
| Gadolonium oxysulfide are _________ turbid and posesses decreased spatial resolution because _______: | Unstructured, light spread |
| Indirect conversion flat panels have a photodiode layer of ______ ________: | Amorphous silicon |
| _________ _______ absorbs the light & converts light to electrons: | Amorphous silicon |
| Indirect flat panel detectors store electrical charge where: | The capacitor of the TFT |
| Direct capture flat panels have a semi-conductive layer of ________ ______: | Amorphous selenium |
| The semi-conductive layer of amorphous selenium absorbs x-rays and ________: | Converts them to electrons |
| Amorphous selenium has a ______ atomic number and is _____: | Low, thick |
| An electrical field is applied across the selenium layer to limit _____ ______ of _____ as they migrate toward the TFT, and what benefit does this provide: | Lateral diffussion or electrons,Maintains spatial resolution |
| Electrical charges (electrons) are stored where before being sent to ADC for digitizing: | Capacitor of the TFT |
| ____ is an old indirect conversion digital system: | CCD or Charge couple device |
| How is the signal linked in CCD: | Lenses or fiber optics that act like cameras |
| The electrical charge in CCD is stored in ___________ ________ and released _______ by ______ and sent to ADC: | Sequential pattern, line by line |
| The cameras in CCD ______ the size of the projected visible light image and transfer the image to one or more ______ or ______ that contains a semiconductive layer and converts the light into an electron: | Reduce, chips or pixels |
| ______ is how much of the x-ray photons are absorbed by the IR: | DQE, Dose quantum efficiency |
| _____ refers to how efficiently a system can absorb and convert xrays into a useful signal: | DQE |
| Which systems offer a higher DQE: | Wider latitude and dyanamic range |
| Which type of panel offers the highest DQE: | Direct conversion |
| Increased SNR results in ______: | Increased image quality |
| ______ is a method of describing the strength of radiation exposure in comparison to the amount of noise apparent in the digital image: | SNR |
| Dose creep is considered _____: | Bad |
| Technique creep is considered _____: | Good |
| What is technique creep used for: | Th eliminate dose creep |
| What is dose creep: | When technologists use higher mAs to achieve a better quality image |
| List the 3 common types of DR image receptors: | Direct conversion, indirect conversion, CCD (Charge couple device) |
| CCDs are considered _______ conversion: | Indirect |
| The three layers of flat panel detectors: | X-ray convertor TFT Glass substrate |
| Each DEL in the TFT consists of: | Semi-conductive material & active layer |
| The electrical components of the TFT consist of: | Capacitor to store electrical charges Switching transistor for readout |
| DELs have a _______ pixel size: | Fixed |
| Spatial resolution is ______: | Fixed |
| The semi-conductive layer of direct conversion flat panels is _________ ________: | Amorphous selenium |
| Indirect conversion flat panels use a _______ to convert xrays to light: | Scintillator |
| The two types of scintillators in indirect flat panels are: | Cesium iodide & gadolinium oxysulfide |
| The scintillator that is considered structured and offers better spatial resolution is: | Cesium iodide |
| The photodector in indirect flat panel is composed of: | Amorphous silicon |
| In both indirect and direct the electrical charge is temporarily stored in the ________ of the _______ and switched to the ____ for digitizing: | capacitor of the TFT, ADC |
| Charge couple devices use a scintillator that is coupled to a CCD by ______ or ________: | Lenses, fiber optics |
| ______ determines the range of histogram data set that should be included and displayed: | VOI |
| _________ suppresses image noise, but degrades spatial resolution: | Smoothing |
| ______ removes superimposing structures: | Subtraction |
| _______ graphic representation of the amount of exposure and incidence of pixels for each: | Histogram |
| ______ uses an S number and has an indirect relationship to exposure: | Fuji & Konica |
| _____ computer identification of the field by locating the edges of the image: | Edge detection |
| __________ noisy image resulting from improper edge detection: | Histogram analysis error |
| ________ Hospital information system: | HIS |
| _________ radiology worklist: | RIS |
| _______ process by which the computer maps the grayscale to the VOI to present a specific display of brightness: | Automatic rescaling |
| ________ number used to indicate the amount of exposure that reaches the IR: | Exposure indicator |
| ______ uses the EI number and has a direct relationship to exposure: | Kodak/Carestream |
| ______ uses lgm and has a direct relationship to exposure: | Agfa |
| _____ used to alter the brightness and grayscale of the low contrast raw image: | Look up table |
| _____ sets the number of shades of graydisplayed on the computer monitor: | Window width |
| _______ monitor that creates the image by accelerating and focusing electrons to strike a fluorescent screen: | CRT |
| Measurement of light intensity; cd/m : | Luminance |
| _______ communication standard for medical information: | HL7 |
| _____ passes light through liquid crystals to display the image on the glass faceplate: | LCD |
| _______ level of room lighting while viewing digital images: | Ambient lighting |
| _______ comparison of a pre-established histogram to the exposure histogram: | Histogram analysis |
| _______ altering the regions viewed on the displayed image. Removing the distractinf white/unexposed borders: | Cropping or shuttering |
| _____ sets the midpoint brightness level: | Window level |
| _______ improves visibility of small high contrast structures, but will increase noise: | Edge enhancement |
| _______ receives, stores, distributes and displays images: | PACS |
| _______ communication standard for information sharing between PACS and imaging modalities: | DICOM |
| Once data is in digital format what are the differences between image processing and image display in CR & DR: | None |
| Is there light produced with CR when radiation interacts with the IP: | Yes |
| The quality of the CR latent image will remain for how long before deteriating: | It begins to lose quality immediately |
| Will a fixed matrix system the sampling frequency is maintained, will a larger IP yield more spatial resolution: | No, DEL (Pixels) remain fixed |
| The barcode label on a CR cassette is used to identify ________: | IP plate |
| When pixel bit depth is increased, ______ is increased and spatial resolution is _________: | amount of colors that can be displayed, increased |
| _______ layer is where electrons become trapped during exposure: | Phosphor |
| ______ layer absorbs and reduces static electricity: | Conductive |
| _________ layer gives imaging sheet strength: | Support |
| _______ layer is a thin, tough, clear plastic that protects the phosphor layer: | Protective |
| ________ layer sends light in a forward direction when released in the CR reader, usually a black layer to reduce simulating: | Reflective |
| ________ layer is used to absorb stimulating light while reflecting emitting light: | Color |
| ______ layer is made of soft polymer layer that provides protection: | Backing |
| PSP stands for: | Photostimulable phosphor |
| The phosphor layer contains ________ ________ doped in _________: | Barium fluorohalide, europium |
| Emission of light when stimulated by a high intensity light beam is termed _________: | Photostimulable luminescence |
| Ionization of the __________ results in electrons being trapped or stored: | Europium atoms |
| Where is the phosphor center: | In the phosphor crystals contained within the phosphor layer |
| The latent image is stored in the _________ until exposed to a high intensity laser beam in the CR reader: | Phosphor centers |
| List the major components of the CR reader: | Drive mechanism Optical mechanism Photodetector ADC |
| The drive mechanism move the IP constantly and slowly along the long axis of the IP. This is referred to as ________: | Slow scan |
| What 2 items are used to deflect the laser beam light back and forth across the IP: | Rotating polygon Oscillating mirror |
| The deflection of the laser beam across the IP is referred to as the _________: | Fast scan |
| List the components of the optical system and their function: | -Laser -Beam shaping optics -Light collecting optic -Optical filter |
| The laser in the optical system provides what function: | Provides stimulating light to IP |
| The Beam shaping optics in the optical system serve what function: | Shapes optic lens to keep diamter under 100um |
| The light collecting optic in the optical system provides what function: | Receives emitted light/directs it to the optical filter |
| The optical filter in the optical system provides what function: | It filters out any long wave length stimulation light from reaching the photodector |
| The __, ___ or ____ collects, amplifies and converts the emitted light into electrical signal and then sends it to ADC: | PD, PMT or CCD |
| Sampling and quantization are a function of ____: | ADC |
| _________ determines the pixel pitch and affects spatial resolution: | Sampling frequency |
| _________ determines the pixel bit depth and affects contrast resolution: | Quantization |
| The signal in the photodector is ______ to the range of energies stored in PSP: | proportional |
| The photodector sends _______ signal to ADC for digitization: | continuos |
| The ____ is capable of receiving, absorbing, and storing an image formed by incident xray photon excitation of phosphors: | IP |
| What two factors are different between CR & DR imaging receptors: | Construction How they acquire the raw data for the latent image |
| A CR uses _______ ______ in place of an intensifying screen: | Antistatic material |
| Photostimulable phosphors ______ electrons during exposure: | Trap |
| The _______ layer absorbs stimulating light but reflects emitted light: while | Color |
| List the two processes of CR: | Image aquisition Image readout |
| Europium is considered a _______ and is responsible for ________: | Activator, storage |
| When is the visible light emitted in CR imaging: | When the outer shell electrons return to their normal metabolic state |
| Xray interaction with a _____ results in excitation of electrons into a metastable state: | PSP |
| Some electrons return to ground state immediately after excitation, resulting in ________: | Immediate light emission |
| CR images should always be processed within ______: | 1 hr |
| Trapped electrons store the latent image until _________: | They are exposed to high intensity laser beam in CR reader |
| The CR ______ _____ is aquired in the PSP layer of the IP: | Latent image |
| Exposed CR imaging plate is placed in a reader to: | -Release stored image -Convert analog image to digital image -Send data to a computer monitor |
| Stages of digitizing include: | -Scanning -Sampling -Quantization |
| The laser reader is made of: | Helium neon or solid state laser diode |
| The laser in a CR reader is used to: | Direct stimulating light to the IP |
| A smaller shaping beam results in ________ spatial resolution: | Increased |
| In digital imaging ______ number of pixels needed to form the image must be sampled or it will result in lack of resolution: | 2X |
| For a given matrix size increasing FOV ______ spatial resolution and decreasing FOV ______ spatial resultion: | Decreases, Increases |
| Fixed spatial resolution systems vary sampling frequency to _____: | Maintain a fixed spatial resolution |
| In fixed spatial resolution a larger IP must have a _____ to maintain the spatial resolution: | Larger matrix |
| Spatial resolution is set by the DEL, systems with smaller DELs have a _______ spatial resolution: | Increased |
Created by:
akhernandez19