16 Questions
Why is a grid not typically used in xeroradiography?
Because it is relatively insensitive to low spatial frequency information
What type of tumors is film-screen imaging particularly useful for visualizing?
Subtle, soft tissue density tumors
What is a convenience of viewing xeroradiographs?
They can be viewed under normal room illumination conditions
What may vary locally and requires advice from colleagues?
The quality of service
Why may the downtime of an xeroradiographic processor be longer than that of a film development unit?
Because xeroradiographic processors are more mechanically complex
What is a potential advantage of having multiple automatic film processors?
One can be used as a backup in case of equipment failure
How does the average glandular dose for non-grid film-screen imaging compare to that of the original xeroradiography system?
It is lower
What may bring the radiation doses from the two techniques closer together?
Using a grid for film-screen imaging
What is a critical factor in producing high-quality mammograms with minimal radiation dose?
Careful selection of equipment, patient positioning, and imaging techniques
What is a characteristic of xeroradiographic systems?
Images display significant edge enhancement
What type of X-ray tube is typically used in film-screen mammography?
Special thin window x-ray tube with molybdenum target
What is the purpose of an antiscatter grid in film-screen mammography?
To improve image contrast
What is a recommended view for xeroradiography?
Medio-lateral view
What is a difference between film-screen and xeroradiographic systems?
Type of X-ray tube used
What is the benefit of using a dual-screen image receptor with double-emulsion anti-crossover film?
Increased dynamic range of tissue attenuation
Why is a grid frequently used in film-screen mammography?
To improve contrast
Study Notes
Mammography
- Mammography is a highly technically exacting radiographic procedure, requiring careful consideration of equipment, patient positioning, and imaging techniques to produce high-quality images at low radiation doses.
Film-Screen Mammography
- Typically uses a single, thin, highly-absorbing intensifying screen and a single-emulsion film.
- Recently, a dual-screen image receptor using double-emulsion anti-crossover film has been introduced.
- Antiscatter grids are widely used for film-screen mammography.
Xeroradiography
- Uses a more penetrating x-ray beam than film-screen mammography.
- Displays significant edge enhancement, providing high spatial resolution and imaging a wide dynamic range of tissue attenuation.
- Especially useful near the chest wall.
Choice of X-ray Equipment
- Xeroradiography: conventional small focus tungsten target tube with aluminum filter, conventional generator operating at 42-52 kVp.
- Film-screen systems: special thin window x-ray tube with molybdenum target and molybdenum filter, generator designed to operate at low kilovoltage (22-35 kVp).
Differences in Patient Positioning
- Film-screen mammography: craniocaudal and medio-lateral oblique views are recommended.
- Xeroradiography: craniocaudal and medio-lateral views are generally used.
- Grid is frequently used to improve contrast in film-screen mammography, but not in xeroradiography.
Differences in Diagnostic Image Quality
- Film-screen imaging: better images of subtle, soft tissue density tumors.
- Xeroradiography: edge-enhanced contrast useful for visualization of microcalcifications and masses with well-defined borders and/or fine, radiating fibers.
Considerations of Convenience and Personal Preference
- Viewing ease: xeroradiographs are viewed by reflected light under normal room illumination, convenient for referring clinicians.
- Film images require low ambient light on a masked viewbox to display subtle contrasts.
- Reliability: equipment reliability and downtime may vary for the two techniques.
Differences in Radiation Dose
- Average glandular dose for non-grid film-screen imaging: two to three times lower than for the original xeroradiography system.
- Increasing use of grids for film-screen imaging may bring the dose from the two techniques closer together when each system is used optimally.
This quiz covers the technical aspects of mammography, including equipment selection, patient positioning, and imaging techniques to produce high-quality images at low radiation doses.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
