Image Production: Equipment Operation and Quality Assurance Flashcards
(47 cards)
221 - To verify the accuracy of the timer on a three-phase equipment, which exposure timer test is utilized?
A. Wire mesh test
B. Spin top test
C. Synchronous timer test
D. Gramophone motor spindle test
C. Synchronous timer test
A three-phase unit’s timer accuracy can be verified using a synchronous timer. Timer accuracy is measured by measuring the degrees of arch of a density band that is formed on the resulting radiograph, as opposed to measuring individual density dots such as with a spin top test. The exposure duration is computed by dividing the density arch’s degrees by 360 degrees.
222 - In the given image of a tube housing, what does A represent?
A. Tungsten
B. Rotor
C. Stator
D. Cathode
D. Cathode
The following is described in this illustration of the envelope and housing of a rotating anode X-ray tube: a spinning anode (A) driven by the bearings of the rotor (R). These generate a focal area of X-ray production surrounding the anode target (T). The cathode (C) is displayed with the filament circuit in green. These components are contained within the evacuated tube envelope (E). The stator (S), which causes the rotor to rotate, is located outside the envelope. In order to prevent the heated oil from over-expanding, an expansion bellows (B), usually attached to a regulator switch, surrounds the tube envelope in a dielectric cooling oil (O). The X-ray beam is emitted through the tube window (W). Lead or copper are commonly used in the housing to attenuate divergent X-rays.
223 - In the given image of a tube housing, what does A represent?
A. Anode
B. Cooling dielectric oil
C. Beryllium tube window
D. Cathode
A. Anode
The following is described in this illustration of the envelope and housing of a rotating anode X-ray tube: a spinning anode (A) driven by the bearings of the rotor (R). These generate a focal area of X-ray production surrounding the anode target (T). The cathode (C) is displayed with the filament circuit in green. These components are contained within the evacuated tube envelope (E). The stator (S), which causes the rotor to rotate, is located outside the envelope. In order to prevent the heated oil from over-expanding, an expansion bellows (B), usually attached to a regulator switch, surrounds the tube envelope in a dielectric cooling oil (O). The X-ray beam is emitted through the tube window (W). Lead or copper are commonly used in the housing to attenuate divergent X-rays.
224 - What does the S represent in this image of a tube housing
A. Anode
B. Cathode
D. Induction stator
C. Evacuated tube envelope
D. Induction stator
The following is described in this illustration of the envelope and housing of a rotating anode X-ray tube: a spinning anode (A) driven by the bearings of the rotor (R). These generate a focal area of X-ray production surrounding the anode target (T). The cathode (C) is displayed with the filament circuit in green. These components are contained within the evacuated tube envelope (E). The stator (S), which causes the rotor to rotate, is located outside the envelope. In order to prevent the heated oil from over-expanding, an expansion bellows (B), usually attached to a regulator switch, surrounds the tube envelope in a dielectric cooling oil (O). The X-ray beam is emitted through the tube window (W). Lead or copper are commonly used in the housing to attenuate divergent X-rays.
225 - By monitoring the mR/mAs output at various mA and time settings, linearity tests can be conducted. During a linearity test, variation cannot exceed what value?
A. +/- 10%
B. +/- 12%
C. +/- 5%
D. +/- 15%
A. +/- 10%
The ability to identify equipment malfunction is an essential skill required of radiologic technologists. During quality assurance testing, it is vital to evaluate exposure linearity and repeatability to ensure that radiography equipment is functioning properly and to identify possible causes of radiographs which are produced too light or too dark. A linearity test can be performed by observing the mR/mAs output across various mA and time settings. This test allows for a maximum variation of 10%.
- Which Letter in this diagram indicates the source of electrons
B
A
C
T
R
C
The following is described in this illustration of the envelope and housing of a rotating anode X-ray tube: a spinning anode (A) driven by the bearings of the rotor (R). These generate a focal area of X-ray production surrounding the anode target (T). The cathode (C) is displayed with the filament circuit in green. These components are contained within the evacuated tube envelope (E). The stator (S), which causes the rotor to rotate, is located outside the envelope. In order to prevent the heated oil from over-expanding, an expansion bellows (B), usually attached to a regulator switch, surrounds the tube envelope in a dielectric cooling oil (O). The X-ray beam is emitted through the tube window (W). Lead or copper are commonly used in the housing to attenuate divergent X-rays.
227 - Which letter in this diagram indicates where x-rays are produced?
R
C
T
S
A
B
T - Anode target
The following is described in this illustration of the envelope and housing of a rotating anode X-ray tube: a spinning anode (A) driven by the bearings of the rotor (R). These generate a focal area of X-ray production surrounding the anode target (T). The cathode (C) is displayed with the filament circuit in green. These components are contained within the evacuated tube envelope (E). The stator (S), which causes the rotor to rotate, is located outside the envelope. In order to prevent the heated oil from over-expanding, an expansion bellows (B), usually attached to a regulator switch, surrounds the tube envelope in a dielectric cooling oil (O). The X-ray beam is emitted through the tube window (W). Lead or copper are commonly used in the housing to attenuate divergent X-rays.
228 - Using self-induction, which component of the X-ray circuit regulates and determines the voltage that is transmitted to the high-voltage transformer’s primary winding?
A. Step-up transformer
B. Autotransformer
C. High-tension transformer
D. High-voltage transformer
B. Autotransformer
The voltage applied to the high-voltage transformer’s primary winding is controlled by the autotransformer. It uses the self-induction principle to function. The mutual induction concept governs the operation of the step-up or high-voltage transformer. The purpose of the step-up transformer is to convert low voltage to the high voltage necessary to generate X-ray photons.
229 - What is the purpose of the step-up transformer?
A. Convert high voltage to low voltage
B. Apply low voltage to the transformer’s primary winding
C. Generate protons
D. Convert low voltage to high voltage
D. Convert low voltage to high voltage
The voltage applied to the high-voltage transformer’s primary winding is controlled by the autotransformer. It uses the self-induction principle to function. The mutual induction concept governs the operation of the step-up, or high-voltage transformer. The purpose of the step-up transformer is to convert low voltage to the high voltage necessary to generate x-ray photons
230 - By stopping the exposure when a predefined amount of ionization and image density is reached, which X-ray technology yields consistent radiographic data?
A. Photomultiplier AEC
B. Photocathode AEC
C. Ionization chamber AEC
D. Phototimer AEC
C. Ionization chamber AEC
Radiographic results can be consistently and comparably produced by means of automatic exposure control (AEC) equipment. One kind of AEC involves an ionization chamber situated above the IR and underneath the tabletop. The anatomical part is centered on the sensor and radiographed, enabling the exposure to automatically end when the appropriate density is reached through a predefined level of ionization. A phototimer (photomultiplier), which is a small fluorescent screen, is placed underneath the cassette in an alternative kind of AEC. The fluorescent screen emits light when the residual radiation from the patient exposes the image receptor (IR) and leaves the cassette. The exposure ceases when the photocell sensor detects a specific quantity of fluorescent light.
231 - For what kind of radiographic unit is a spin top test conducted?
A. Three-phase unit
B. Half-wave rectified unit
C. Fully rectified unit
D. A and B
E. Single-phase unit
E. Single-phase unit
For single-phase units, an exposure timer test called a spin top test can be conducted. In the case of a half-wave rectified unit, this test produces a visible number of dots of density equal to the exposure timer setting × 60, and in the case of a completely rectified unit, equal to the exposure timer setting × 120. Any fluctuation in the dots seen on the radiograph suggests a faulty timer or rectifier.
232 - For a radiographic examination, a 72-inch SID is utilized. What is the minimum distance that the radiation field needs to be aligned with respect to the edge of the light field?
A. +/- 1.4 inches
B. +/- 3.6 cm
C. +/- 2 cm
D. +/- 2.1 inches
E. A and B
E. A and B
Accurate beam restriction requires the light field to radiation field alignment to be within plus or minus 2% of the source to image distance (SID). 1.4 inches, or 3.6 cm, is the equivalent to 2% of a 72-inch SID. Positive beam limitation, for example, is one kind of beam restricting device. When employing automatically light-localized variable aperture collimators, the field control must be within 2% of the SID.
233 - The quantity of scatter radiation that reaches the image receptor (IR) rises with kVp. What impact does this have on radiographic contrast?
A. Contrast is unchanged, but quantum mottle results
B. Contrast is unchanged, but density decreases
C. Contrast decreases
D. Contrast increases
C. Contrast decreases
The amount of scatter radiation that reaches the image receptor (IR) increases with an increase in kVp. This causes a decrease in radiographic contrast.
234 - Computed radiography (CR) employs reusable solid-state image receptors (IRs). What is the active ingredient that absorbs X-ray energy and becomes energized?
A. Amorphous selenium
B. Amorphous silicon photodiodes
C. Cesium Iodide scintillation phosphor
D. Europium-activated barium fluorohalide
D. Europium-activated barium fluorohalide
A reusable solid-state image receptor and photostimulable phosphor (PSP) are used in computed radiography (CR), a type of digital radiography. The active ingredient in the cassette-based CR system is europium-activated barium fluorohalide. The PSP’s sensitivity is comparable to that of a 200-speed film/screen system.
235 - Which of the following is an essential component of the CR plate reader?
A. Photomultiplier tube
B. Cesium Iodide scintillation phosphor
C. Thin-film transistor
D. Active matrix array
A. Photomultiplier tube
A reusable solid-state image receptor and photostimulable phosphor (PSP) are used in computed radiography (CR), a type of digital radiography. By subjecting a latent image to a high-intensity laser beam, the CR image is made visible. Trapped electrons in the PSP can return to the valence band when the laser beam releases violet light. An extremely sensitive photomultiplier tube detects violet emission and transforms the light into an electrical signal. The photomultiplier tube’s electrical signal is converted to digital form and saved for later viewing on a computer monitor. The PSP becomes active in response to as little as 10 µR. A PSP should be erased if it is not used for more than 48 hours.
236 - Solid-state detectors are used in the cassette-less direct digital radiography system. Processing can be accomplished in two ways: one method coats an active matrix array of amorphous silicon photodiodes with a cesium iodide scintillation phosphor, while the other method does not. Which technique yields the greatest spatial resolution?
A. The method which involves coating CsI over an AMA of a-Si photodiodes
B. The method in which remnant radiation interacts directly with a-Se
C. Both methods yield the same level of spatial resolution
D. The CsI method offers both enhanced spatial resolution and lower patient dose
B. The method in which remnant radiation interacts directly with a-Se
Solid-state detectors are used in the cassette-less direct digital radiography system. Remnant radiation interacts directly with a thin layer of amorphous selenium (a-Se), producing electron hole pairs (EHP). The thin-film transistors’ (TFTs) active matrix array (AMA) is charged by the EHP signal. Superior spatial resolution is achieved by the phosphor coating-free a-Se processing approach. Comparatively, reduced radiation dosage to the patient and high detective quantum efficiency (DQE) are two advantages of the CsI phosphor method.
237 - Direct digital radiography can be achieved through use of which components?
A. Thin-film transistors
B. Cesium Iodide scintillation phosphors
C. Amorphous silicon photodiodes
D. Amorphous selenium
E. All of the above
E. All of the above
The cassetteless direct digital radiography system uses solid-state detectors. There are two approaches to processing: the first applies a cesium iodide scintillation phosphor to an active matrix array of amorphous silicon photodiodes, whilst the second approach does not. Remnant radiation directly interacts with a thin layer of amorphous selenium (a-Se) in the approach that does not make use of the phosphor coating, creating electron hole pairs (EHP). The EHP signal charges the active matrix array (AMA) of thin-film transistors (TFTs). The a-Se processing method without phosphor coating can yield better spatial resolution. In contrast, the CsI phosphor technique offers two advantages: a lower radiation exposure to the patient and a higher detective quantum efficiency (DQE).
238 - The ability to modify a digital image’s brightness and contrast is achieved through which of the following?
A. Networking
B. Leveling
C. Rescaling
D. Windowing
D. Windowing
The capability to modify a digital image’s contrast and/or brightness is known as windowing. Digital systems with automatic rescaling can generate images with a consistent brightness display throughout a broad exposure range.
239 - What impact does SID have on radiographic density?
A. SID is unrelated to density, and inversely related to contrast
B. As SID decreases, density decreases
C. SID is unrelated to density, and directly related to contrast
D. As SID increases, density decreases
D. As SID increases, density decreases
There is an inverse relationship between SID and radiographic density. Density decreases with increasing SID. The amount that density varies as SID is changed is determined by the inverse square law. If SID is altered, the change in mAs needed to produce an image with a similar density is determined by the direct square law.
240 - What technical parameter influences tissue attenuation, radiographic contrast, and beam penetrability?
A. mAs
B. OID
C. S-number
D. kVp
E. A, B, and C
D. kVp
Raising kVp makes the x-ray beam more penetrating, but tissue attenuation capacity falls and radiographic contrast is reduced.
241 - What percentage of kVp modification is necessary to achieve an appreciable alteration in density within the radiographic image?
A. 25%
B. 20%
C. 15%
D. 10%
C. 15%
A kVp modification of at least 15% is required in order to produce an appreciable change in density within the radiography image. Generally, if a radiograph must be reacquired because of overexposure or underexposure, the exposure variables used to produce the original radiograph should be doubled or halved.
242 - Which stage of image processing involves the conversion of an analog signal to a digital value?
A. Developing
B. Acquisition
C. Archiving
D. Data manipulation
B. Acquisition
The process of obtaining and recreating an image on a digital platform is known as image acquisition. It entails the methodical application of extremely intricate mathematical concepts and computations known as algorithms. Analog signals, or electrical pulses, are transformed to digital values throughout the image acquisition process.
243 - The reciprocity law formula states that density rises or falls in proportion to:
A. kVp
B. SID
C. mAs
D. Film-screen speed
C. mAs
Density is one aspect influencing image evaluation. Density follows the reciprocity rule formula, increasing and decreasing proportionately with mAs.
244 - What percentage of mAs modification is necessary to achieve a noticeable change in density within the radiographic image?
A. 50%
B. 10%
C. 15%
D. 30%
D. 30%
A mAs modification of at least 30% is required in order to produce an appreciable change in density within the radiography image. Generally, if a radiograph must be reacquired because of overexposure or underexposure, the exposure variables used to produce the original radiograph should be doubled or halved.