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206 midterm
| Question | Answer |
|---|---|
| Computer programs are called software | True |
| As image noise increases contrast decreases | True |
| The smaller the pixels the lower the spatial resolution | False |
| Computer equipment is called software | False |
| Computer equipment is called hardware | True |
| As window level increases image density decreases | False |
| The most familiar computer input device is a keyboard | True |
| A digital image is one that is converted into a picture for transmission or processing | True |
| As window with increases image contrast decreases | False |
| A pixel is a square series of boxes that gives form to the image | False |
| As matrix size increases image resolution increases | True |
| The individual matrix boxes are known as pixels | True |
| In medical imaging each pixel value corresponds to the three dimensional volume of tissue known as voxel | True |
| CR Imaging plates are more sensitive to scatter than radiographic film | True |
| The goal of hospitals is to allow patients information to be exchanged between an interconnected HIS and RIS | True |
| An increase in number of pixels results in an increase in resolution | True |
| Soft copy display refers to images that are visualized on film | False |
| A PACS system is used to convert analog film to digital images | False |
| The CR Imaging plate is only sensitive to scatter after it is sensitized through exposure to the x ray beam | False |
| When fluorohalides luminescence they release all their energy as light | True |
| The latent image stored on the CR Imaging plate had wider energy latitude than radiographic film | True |
| All monitors in a workstation should have the same level of luminescence | True |
| When the main power to the computer is turned off,_ is erased? | RAM |
| When the main power to the computer is turned off,_ is maintained? | ROM |
| Which does not store memory? Floppy disk Diskette Optical disk Mouse | Mouse |
| Which is not used as an input device? Keyboard Voice activation Touch screen Laser disk | Laser disk |
| Which is not output device? CRT screen Ultrasound transducer Printer Laser film | Ultrasound transducer |
| Detectors can detect information from which source? | Ionizing radiation Ultrasonic waves Radio frequencies |
| Detectors acquire information 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 PSP Imaging plates CCD Capacitor receptors Silicon receptors | Capacitor plates |
| Silicon and selenium receptors are also known as | Flat panel detectors |
| Which type of system uses a two part process to convert incoming x ray photons to an electric signal? | Indirect conversion |
| During two part conversion, a _ converts x ray photon to light | Scintillator |
| During two part conversion, a _ converts light to an electronic digital signal | Photo detector |
| Digital radiography cassettes are also known as | Film-less cassettes |
| The active layer of the CR Imaging plate is made of | Photostimulable fluorohalides |
| The latent image is created by energy transfer during | Photoelectric interactions |
| When the CR Imaging plate is scanned the phosphors of the latent image release energy in the form of | Light |
| A CR artifact caused by the Imaging plate being exposed to intense heat is | Heat blur |
| What are advantages to the DR over film? | Digital images can be manipulated without re exposure to patients Digital images can be sent to remote locations Digital images require less physical storage |
| Gray scale bit depth ranges from | 8-32 bits |
| 1.How many shades of gray can be displayed with a bit depth of 10 bits? a.256 b.512 c.1024 d.2048 | c.1024 |
| The amount of exposure required for CR is similar to which of the following film-screen systems? a.100 b.200 c.400 d.800 | b.200 |
| What is the spatial resolution of a 24 cm x 30 cm IP? a.2 lp/mm b.3 lp/mm c.4 lp/mm d.5 lp/mm | C. 4 lp/mm A 24 cm wide imaging plate is also 240 mm wide. If the plate is scanned at a frequency of 2000, then there would be 8 pixels/mm. It takes two pixels to make a line pair, so the spatial resolution would be 4 lp/mm. |
| 1.A cassette-based IP requires ______ of exposure to produce an optimum quality image. a.0.5 mR b.1.0 mR c.2.0 mR d.5.0 mR | 1.0mR |
| 1.Which of the following occurs when the IP or detector is grossly overexposed? a.Saturation b.Intensification c.Dynamic quantum d.Dynamic inefficiency | Saturation |
| 1.In digital radiography, Nyquist is referring to which of the following? a.The efficiency of the flat panel detector b.The accuracy of the histogram c.The sampling frequency of the digital data d.The brightness of the laser beam | The sampling frequency of the digital data |
| 1.If the Nyquist frequency and the grid frequency are approximately the same, which of the following may occur? a.Histogram error b.Moire effect c.Grid cutoff d.Dark image | Moore effect |
| 1.Edge enhancement can be applied to a digital image to improve which of the following? a.The black border around the edge of the image b.The loss of detail in the image c.The contrast along the edges of a structure d.The sharpness of structural lines | The contrast along the edges of a structure |
| 1.Applying too much edge enhancement to a digital image can result in which of the following? a.Loss of visibility of details b.Halo artifact c.Noise d.Loss of recorded details | Halo artifact |
| 1. Thin film transistors (TFT)are found in which type of digital system? a.CR b.Cassette-less c.Cassette-based d.CCD | Cassette-less |
| 1. The latent image can remain âstoredâ in the PSP plate for _____ hours before information is loss. a.8 b.16 c.24 d.36 | 8 hours |
| 1.Contrast resolution is a major advantage of digital imaging. What determines high contrast resolution in a digital image? a.High exposure and low noise b.Low exposure and high noise c.High exposure and high resolution d.High resolution and low noise | High exposure and low noise |
| 1.A flat-panel detector requires ______ of exposure to produce an optimum quality image. a.0.5 mR b.1.0 mR c.2.0 mR d.5.0 mR | 0.5mR |
| 1. _____ releases electrons when struck by light photons and _____ releases electrons when struck by x-ray photons. a.Gadolinium oxysulfide, cesium iodide b.Amorphous silicon, amorphous selenium c.Amorphous selenium, amorphous silicon d.Silver bromide, zi | Amorphous silicon,amorphous selenium |
| 1.What is the definition of amorphous? a.A noncrystalline state of an otherwise crystallline material b.The process of emitting light when stimulated by x-rays c.Converting x-ray to light d.Storing electrical charge for digital viewing | a.A noncrystalline state of an otherwise crystallline material |
| 1.Detectors can detect information from which source? a.Ionizing radiation b.Ultrasonic waves c.Radiofrequencies d.All of the above | All of the above |
| 1.Detectors acquire information by; a.Scanning b.Array detection c.Both a and b d.All of the above | A and B |
| 1.The latent image is created by energy transfer during; a.Pair production b.Coherent scatterring c.Photodisintegration d.Photoelectric interactions | Photoelectric interactions |
| 1.The latent image will lose about 25% of its energy in; a.3 seconds b.10 minutes c.8 hours d.24 hours | 8 hours |
| 1.The CR plate is scanned by a(n); a.Helium-neon laser beam b.Ultraviolet light beam c.Infrared heat source d.All of the above | A |
| 1.When the CR imaging plate is scanned, the phosphors of the latent image release energy in the form of: a.Heat b.Light c.Electricity d.None of the above | B |
| 1.During CR imaging plate processing, the laser frees trapped electrons, allowing them to return to a lower energy. This process is known as: a.Photostimulated luminescence b.Thermal emission c.Green-light phosphorescence d.None of the above | A |
| 1. During CR imaging plate processing, when the laser frees trapped electrons, allowing them to return to a lower energy state, which type of light photon is released? a.Red-orange b.Ultraviolet c.Blue-purple d.Green-yellow | C |
| 1. The response of the imaging plate to ionizing radiation is; a.The characteristic curve similar to the one for film b.The D log E curve c.The H and D curve d.linear | D |
| 1. A CR artifact caused by insufficient mAs is; a.Quantum mottle b.Heat blur c.Histogram error d.Nonpararellel collimation | A |
| 1. A CR artifact caused by incorrect preprocessing histogram histogram selection is; a.Quantum mottle b.Heat blur c.Histogram error d.Nonpararellel collimation | C |
| 1. A CR artifact caused by bthe imaging plate being exposed to intense heat is; a.Quantum mottle b.Heat blur c.Histogram error d.Nonpararellel collimation | B |
| 1. Production of a grainy, reticulated image that cannot be corrected in digital post-processing is the result of: a.Failure to use high enough mAs setting b.Failure to use high enough kVp setting c.Failure to use the correct algorithm d.Failure to use th | A |
| What is the principle difference between film screen and CR? | Analog v.Digital |
| Doping of PSP with europium result in | More stimulants light emission |
| Which step is eliminated during switching from film to CR? | Reload cassette |
| Monochromatic | Laser light |
| CR Imaging display how many shades of gray | 10,000 |
| In scanned projection digital radiography which moves o produce image | Patient |
| DR Imaging system_ than screen film rad | Use film as the image receptor |
| An electron that is described as being metastable | Has higher energy than it should have |
| Unique to DR | No cassette required |
| Used as image receptor in DR | a-Se |
| Used as a radiation detector in DR | a-Se |
| Image receptor in CR could be | BaFICI |
| Most important for soft tissue contrast | Contrast resolution |
| Spatial frequency consists of unit | lp/mm |
| 12bits how many shades of gray | 4096 |
| The principle advantage of DR over film screen | Contrast resolution |
| DQE is measure of | X ray absorption |
| Spatial resolution in DR is determined principally by | Pixel size |
| What happens at the K edge of the phosphor of receptor? | Higher x ray absorption |
Created by:
ZMM