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Mammography2
Instrumentation and Quality Assurance
Question | Answer |
---|---|
In mammography, selecting extremely low kVp values | increases contrast but increases patient dose |
What target-filtration combination provides the best penetration for dense or thick breast? | rhodium target with rhodium filtration |
The material used for the exit port of the mammography tube is necessary because | Regular glass would harden the emerging beam. |
The intensity of the x-ray beam from the cathode side of the tube is generally higher because | The heel effect causes variation in the intensity of the x-ray beam. |
The design of the lip of the compression paddle (both height and angle along the chest wall) affects all of the following | -prevents the posterior and axillary fat from overlapping the body of the breast -allows uniform compression of the posterior breast tissue -helps to increase structural strength of the compression paddle |
The primary goal of compression is to | allow uniform penetration of structures within the breast. |
AEC failure, resulting in an underexposed radiograph, can be caused by | improper placement of the dense breast tissue/size over the detector |
Most AEC circuitry in modern mammographic imaging has at least three detectors. Three or more detectors are recommended because | Multiple detectors allow for maximum variations in breast size and tissue density. |
The major difference between the general radiography grid and the grid used in mammography is that the | grids used in general radiography have higher ratios |
As the size of the x-ray field decreases, to maintain a constant image density the exposure will | increase |
The chest wall edge of the compression paddle should be aligned just beyond the chest wall edge of the IR to | avoid projecting the chest wall edge of the paddle on the mammogram. |
Which of the following affects focal spot size? | angle of the anode |
In mammography, the commonly used focal spot size for routine work is | 0.3 mm |
Which of the following characteristics are unique to mammography cassettes? | generally have a single intensifying screen. |
Two main disadvantages of extended processing are | increased processing artifact and increased film fog |
In digital mammography, both the film and cassette can be replaced by | a detector and electronic system |
The greatest difference between digital technology and conventional mammography imaging is | In digital technology, the final image can be manipulated |
All of the following are characteristics of double emulsion film/screens combination. Which characteristic makes these systems undesirable in mammography use? | The system has a lower spatial resolution than the single emulsion systems. |
Film fog is best demonstrated on the characteristic curve as | the toe of the graph |
The characteristic curve, obtained by plotting density values from a sensitometer, can be used to assess all of the following exvept: | to compare the x-ray beam quality with different films |
The characteristic curve of two films is plotted.The curve of film A is positioned to the left of the curve of film B. | -film A is faster than film B -at any optical density, film A will require less exposure than film B |
Which of the following mammographic quality control tests is performed monthly? | visual checklist |
Adequate "air bleed time" refers to the | elapsed time between film loading and exposure |
Which of the following quality control tests does not require a densitometer? | screen cleanliness |
The criteria to pass the ACR Mammography Accreditation on conventional phantom imaging require a minimum of ___ masses. | three |
In establishing processing quality control operating levels, the speed index is designated as the density | closest to but not less than 1.20 |
For the daily quality control testing, the base-plus-fog level should remain within | +0.03 of the established levels |
The screen-cleaning test should be carried out whenever | a mammographer notices dust artifacts on the image |
Before processing the sensitometric strip each day, the mammographer should | check the developer temperature |
The phantom image background optical density should never be | less than 1.20 |
In the darkroom fog test, the optical density difference between fogged and unfogged areas of the film should not exceed | 0.05 |
In viewing phantom image, which of the following viewing conditions need not apply? | using the same film emulsion batch |
In the test for screen contact there were multiple points of small areas (<1 cm in diameter) of poor contact. The corrective action is to | return the cassette to clinical use |
One of the two reasons towels are used in the compression test is to | protect the cassette holder |
For the repeat analysis to be meaningful, a patient volume of at least ___ patients is needed. | 250 |
Daily processing control can involve all of the following except | using the sensitometer to measure the densities on the strip |
Proving that a darkroom fog failure is a result of safelight problems involves | repeating the test with the safelights off |
The darkroom fog test is performed | semiannually |
Daily processor control is used to | -determine the film speed -check the film contrast -check the stability of the processor |
If, after examining a phantom image, the number of visualized fibers of masses has changed significantly, the next step is to | check the mammography unit or the image processor |
Repeated films are | films that involve exposure to the patient |
If the patient volume at a mammography site is 200 patients per week, the repeat/reject analysis should be done every | 3 months |
All the fluorescent tubes in the mammography view box should be replaced at the same time because | Fluorescent tubes decrease in brightness with age |
In imaging the phantom, the technical factors used should be the same as those used clinically for a __-cm-thick breast of medium glandularity. | 4.0-4.5 |
Mammography facilities can receive certification from | -the FDA -an SAC state |
An MQSA certificate is issued when a mammography facility has been accredited. This certification is valued for | 3 years |
If any of the visual checks fail, the first step is to | correct or replace the item |
Digital images can be viewed on a computer monitor or printed using | dry laser technology |
Hardcopy viewing of the digital imaging describes | the image that is sent for interpretation |
The grid ratio can vary in modern mammography units. A common grid ratio used is | 4:1 |