EAQ Quizzes
A luminance meter should use a calibration method that is traceable to the National Institute of Standards and Technology (NIST) and should be able to measure luminance in what range?
0.05 to 1000 cd/m 2
Which factors influence shape distortion?
1)Central ray angulation 2)Alignment of the beam 3)Geometry of the beam
Which patient factors cause involuntary motion and lead to blurred radiographic images?
1)Fear 2)Mental illness
Which factors influence image contrast? .
1)Source-to-image-distance (SID) 2)Object-to-image-distance (OID) 3)Focal spot size 4)Alignment of anatomical part
What is the result if the added filtration is increased?
1)The image contrast increases. 2)The scatter radiation decreases. 3)The x-ray beam quality increases.
What are the dimensions of luminance variations that should be observed on the TG 18-UNL80 test pattern?
1. 0.5 cm 2. 0.8 cm 3. 0.7 cm
Which may be used as the typical backup settings for automatic exposure control (AEC)?
1. 1.5 times the expected exposure time 2. 150% to 200% the expected exposure time
What actions should take place prior to beginning the preparation of the radiographic technique chart?
1. A standard for imaging studies should be confirmed. 2. X-ray equipment must be calibrated by a medical physicist.
How can a radiographer reduce the motion caused due to the movement of the lungs during a patient's breathing?
1. By reducing the exposure time 2. By asking the patient to hold his or her br
What is true regarding digital radiography (DR) versus screen-film radiology?
1. DR is faster to process 2. DR is easier to view from multiple locations.
What is the function of the thin-film transistor (TFT) array?
1. Isolating each pixel element 2. Sending electrical charges to the image processor
What is the advantage of the line-focus principle?
1. It improves heat capacity. 2. It improves spatial resolution.
What happens when a long source-to-image receptor distance (SID) is used?
1. It reduces focal spot blur 2. It improves spatial resolution 3. It results in less magnification
When should an automatic exposure control (AEC) system be calibrated?
1. Out of range exposure index numbers 2. Upon installation of new AEC equipment 3. Department change in image receptor systems 4. Intervals determined by the physicist/department protocol
What information should be included on all radiographs?
1. Patient name 2. Date of exam 3. Right or left marker
What information should be included on all radiographs?
1. Patient name 2. Date of exam 3. Right or left marker 4.
Sensors used during automatic exposure control (AEC) exposure detect which types of radiation that will terminate exposure?
1. Scatter 2. Primary 3. Remnant
Which materials are used in a flat panel detector? .
1. Selenium 2. Cesium iodide 3. Amorphous silicon
Which structures represent types of automatic exposure control (AEC) devices?
1. Solid-state diode 2. Ionization chamber
A radiographic image displays with obvious quantum noise (mottle). Which is true?
1. The exposure indicator displays a value that indicates insufficient technical factors were used to obtain the image. 2. mAs should be increased for the repeat exposure.
Which patient factors may affect image quality when using automatic exposure control (AEC)?
1. Thickness 2. Pathologic conditions 3. Orthopedic hardware
What is the purpose of adjusting kilovolt peak (kVp) during a radiographic examination?
1. To adjust voltage 2. To reduce the patient's dose 3. To affect the quality of the x-ray beam
Why does a radiologic technologist implement immobilization techniques?
1. To reduce the radiation dose 2. To avoid the need for a repeat exposure 3. To avoid blurring of the radiographic image
When a radiographic technique chart is found to be inadequate, what factors should be checked first?
1. X-ray beam coincidence 2. Appropriate grid is being used 3. Beam restrictor checked for accuracy
When radiographs are taken in automatic exposure control (AEC) mode, the electronic timer should be set to how many times the expected exposure time as a backup timer in case the AEC fails?
1.5 times
When radiographs are taken in the automatic exposure control (AEC) mode, what timer setting is recommended?
1.5 times the anticipated exposure time
Which factors can control size distortion?
1.Source-to-image distance 2.Object-to-image distance
Which is the minimum kVp typically found on high-kVp technique charts?
100 kVp
What milliampere seconds (mAs) value would result using the 500 mA setting at 0.25 seconds?
125 mAs
A radiograph is made using 40 milliampere seconds (mAs) at a 40-inch SID. If the image must be repeated at a 72-inch SID, what mAs value is necessary to maintain the same exposure?
130 mAs
A radiographic image is made at 200 mA and an exposure time of 100 ms. How can this be expressed in mAs?
20 mAs
A radiographic examination requires 120 mAs at 200 cm source-to-image receptor distance (SID). What should the new mAs be at 100 cm SID in order to maintain exposure to the IR?
30 mAs
A radiographic procedure is performed at 150 mA for 120 ms. Which milliamperes (mA) setting results in the same exposure, but half the initial exposure time?
300 mA
If any particular examination requires 8 mAs to produce a radiograph using a 500 speed image receptor, how much mAs is required for a 700 speed image receptor at the same voltage?
5.7 mAs
A radiologic technologist wants to use 100 milliampere-seconds (mAs). If the generator has the capacity from 200 milliamperes (mA) to 1000 mA, what should be the maximum exposure time for the examination?
500 ms
For most x-ray examinations of the spine and trunk of the body, the optimal kilovolts peak (kVp) is approximately what value on the technique charts?
80 kVp
Which kilovoltage setting range would be most appropriate for adequate penetration of a lateral lumbar spine on a digital system?
90 to 100 kVp
In addition to patient identification, what process is often helpful in informing the clinician about anatomy and exam information?
Annotation
A foundation technique chart is one made for which patient population?
Average-sized adult patients
Where is the automatic exposure control (AEC) chamber located?
Between the patient and the image receptor (IR)
Which capture element is used in indirect digital radiography?
Cesium iodide
Which component controls the size and shape of the x-ray exposure field?
Collimator assembly
What is the function of milliampere-seconds?
Control of the quantity of x-ray photons
When is penumbra increased?
Decreasing the distance between the beam and the object
Which circuit element allows electrons to flow only in one direction?
Diode
Which postprocessing function increases noise that is already present in an image?
Edge enhancement
What is the most likely reason for loss of contrast and loss of distinct images in an image?
Excessive exposure
Variable kilovoltage chart
Exposure directed by what type of radiographic technique chart usually results in higher patient radiation dose and less exposure latitude?
Which type of technique chart may result in more uniform images?
Fixed kilovoltage chart
Offset images and gain images are automatic calibration images designed to make the response of the image receptor uniform. What are these preprocessing calibration techniques identified as?
Flatfielding
5 years
For what period of time should radiology records, report copies and printouts, films, scans, and other image records of adult patients be retained?
Which combination is appropriate when imaging the chest of a patient?
High kVp; low mAs
What type of exposure techniques are ideal for barium work to ensure adequate penetration of the barium?
High kilovoltage techniques
Which type of power generators are used to produce the maximum quantity and quality of x-ray image?
High-frequency generators
Decreased by 25%
How much is the radiation quantity changed from the preset radiation detection value when the exposure control is set at −1?
53 kVp
If a phantom knee measures 14 cm thick, what kilovolts peak (kVp) should be used to begin construction of a variable-kVp technique chart for a three-phase x-ray machine?
What does the radiologic technologist check on the display monitor to assess the reason for the mirror images?
Images of light sources
Therapeutic radiology
In which modality is the amount of dose of the X-ray or radioactive material administered, as well as the date and time required to be documented in the medical record?
How does high kilovolt peak affect the x-ray beam?
It results in higher energy.
What will happen if the source-to-image-receptor-distance (SID) is increased?
It will increase image sharpness.
What is the most likely cause of warping and rotational friction of the anode?
Long exposure time
The lower jaw and associated teeth are radiographed in a patient complaining of a toothache. Which post-processing technique is useful for improving the visibility of the minutest roots of the teeth?
Magnification
Which process helps to improve the visibility of a digital image?
Magnification
Which should be used to ascertain partial thickness for accurate technique selection?
Measuring caliper
Most electric exposure timers are controlled by which device?
Microprocessor
Which association provides the guidelines to transfer a radiographic image to various DICOM-compatible display devices without altering its gray scale?
National Electrical Manufacturers Association (NEMA)
Which component of the x-ray imaging system would one use to control the exposure time and milliamperes (mA) during a radiographic examination?
Operating console
Spatial resolution in digital radiography is primarily determined by which factor?
Pixel size
A radiographic technologist is performing a radiographic examination of the thoracic spine. Which position takes advantage of the heel effect and will reduce focal spot blur?
Positioning the abdomen toward the cathode and the neck towards the anode
Consistent image quality when producing radiographs using automatic exposure control (AEC) is primarily controlled by which factor?
Proper patient/part positioning over the activated detector
Which device is used to evaluate the exposure reproducibility of the x-ray tube?
Radiation dosimeter
What is a SMPTE pattern used for?
Resolution of display systems
Which adjustment will have an impact on contrast to noise ratio (CNR) in digital radiography?
Scatter radiation decreased
What is the first step in beginning the preparation of a variable-kVp radiographic technique chart?
Select the body part for examination.
How frequently should the collimation of the x-ray tube be evaluated?
Semiannually
How can a radiologic technologist obtain high-quality diagnostic images when involuntary patient motions, such as peristalsis, occur?
Setting short exposure times
Which material is used in the manufacturing of solid-state rectifiers in an x-ray circuit?
Silicon
What mechanism allows the radiographic technologist to make minor adjustments to the position of a ceiling-supported x-ray tube?
Single-control lock system
Which postprocessing function helps with viewing small anatomical parts by removing image noise?
Smoothing
Which factor affects the geometric properties of an image?
Source-to-image distance
In which scenario is automatic exposure control (AEC) most likely to produce an acceptable radiograph?
Spine radiography
Which accrediting agency sets the guidelines for medical record documentation?
The Healthcare Facilities Accreditation Program
What organization requires the health record to contain sufficient information to identify the patient, support the diagnoses, justify the treatment, document the course and the results, and facilitate continuity of care?
The Joint Commission
What can be concluded if the minimum total filtration is found to be 3.1 mm Al while evaluating a general purpose radiographic unit?
The filtration is adequate.
Which is true regarding the radiology facility's responsibility for retaining adult patients' imaging and radiology records?
They must be retained for 5 years from the date that the patient is last seen by the facility.
Which collection element is utilized with indirect and direct digital radiography?
Thin-film transistor
Why must the automatic exposure control ionization chamber be radiolucent?
To avoid interference with the radiographic image
Why does a radiologic technologist increase source-to-image distance (SID) and use a small focal spot size during the radiographic examination?
To increase image resolution
Why does a radiologic technologist use the small focal spot while performing radiographic examination?
To obtain fine details of small bones
What is the primary purpose of the backup time in an automatic exposure control (AEC) system?
To protect the tube from overheating and the patient from overexposure
Why is it necessary to evaluate the exposure time accuracy during a quality control program?
To reduce patient dose
What can a radiologic technologist do to improve recorded detail?
Use a small focal spot
Which action results in low spatial resolution?
Using the largest image receptor
Decrease the milliampere-seconds (mAs).
What change to the typical technique chart is necessary when imaging the abdomen of a patient with ulcerative colitis?
The mandible, cranium, and vertebrae are symmetrical.
What criteria are used to measure rotation for an anteroposterior (AP) projection of the dens?
Image lag
What phenomenon can be troublesome when switching from high-dose to low-dose techniques, such as switching from digital subtraction angiography (DSA) to fluoroscopy?
The patient's neck is flexed too much toward the chest.
What positioning error has been made if the patient's upper teeth are visualized over the dens for an open mouth anteroposterior (AP) projection of the dens?
1. Lag correction 2. Noise correction 3. Pixel interpolation
What preprocessing actions are automatically applied with most systems?
High kilovoltage techniques
What type of exposure techniques are ideal for barium work to ensure adequate penetration of the barium?
At the proper exposure of the image receptor (IR)
When does automatic exposure control terminate the X-ray exposure?
1. mA 2. kVp 3. Optical density 4. Proper sensors 5. Backup time
When using automatic exposure control (AEC), the radiologic technologist can still select or change which factors?
Worklist in the radiographic exam room
Where would a radiologic technologist most likely encounter the RIS?
1. Flat display surface 2. Modulation of light 3. Pixel cross-talk distortion
Which are characteristic features of an active matrix liquid crystal display (AMLCD)?
Proximal one-third of metacarpals to distal radius and ulna
Which bony landmarks must be included on a posteroanterior (PA) projection of the wrist?
1. Increase in kV 2. Increase in mA 3. Decrease in grid ratio
Which changes result in a decrease in exposure time when using automatic exposure control (AEC) to produce a radiographic image?
1. Increase in grid ratio 2. Decrease in kilovoltage
Which changes would increase image contrast?
Increase in spatial resolution
Which describes the effect of an increase in matrix size on digital image quality?
1. Grid ratio 2. Scatter radiation 3. Quantum mottle 4. Beam restriction
Which factors affect contrast to noise ratio (CNR) in digital radiography?
Flat panel detectors with amorphous selenium
Which is a direct capture digital image receptor?
1. It helps in proper separation of the images. 2. It results in proper collimation of the images. 3. It helps in proper projection of multiple fields onto a single imaging plate.
Which is true regarding partitioning in digital radiography?
90 to 100 kVp
Which kilovoltage setting range would be most appropriate for adequate penetration of a lateral lumbar spine on a digital system?
Fill factor
Which portion of the pixel face is sensitive to x-rays?
Exposure index
Which term is used to refer to the numeric representation of the quantity of exposure received by a digital image receptor?
Increase in beam restriction
Which will increase contrast resolution in a digital image?
1. Decrease in kVp 2. Increase in grid ratio 3. Increase in beam restriction
Which will result in an increase in contrast to noise resolution (CNR)?