Additional screen-film mammography information
It has been demonstrated that routine screening with high quality mammography is effective in reducing mortality from breast cancer in women aged 40-69. In order to detect breast cancer accurately and at the earliest possible stage, the image must have excellent contrast to reveal mass densities and spiculated fibrous structures radiating from them that are characteristic of cancer. In addition, the spatial resolution must be excellent to reveal the calcifications, their number and their shape. It has been well established that to achieve high quality mammography the following elements are essential: (i) well-trained and experienced personnel (radiologist, radiographer, medical physicist), (ii) modern, well designed equipment (iii) equipment in good working order (iv) proper positioning and technical factors for exposure and (v) appropriate image viewing conditions. An effective quality assurance programme is necessary to ensure that all of these elements remain in place over time.
Relevant documents: Quality Assurance Programme for Screen Film Mammography (IAEA)
1. Principles of QA
A quality assurance (QA) programme in diagnostic radiology, as defined by the WHO, is an organized effort by the staff operating a facility to ensure that the diagnostic images produced are of sufficiently high quality so that they reliably provide adequate diagnostic information with both the lowest possible cost and the least possible exposure of the patient to radiation consistent with the requisite level of image quality. The establishment of a comprehensive QA program for medical diagnosis is required for this with the technical aspects of such a programme under the supervision of an appropriate medical physicist.
Relevant Human Health Website cross-links: Technology Management
2. Clinical considerations for mammography
This section contains a full treatment on positioning and compression and clinical image evaluation.
The section on clinical image quality is taken with permission from the American College of Radiology. Permission was not given to reproduce this material for electronic distribution, so is only available in the hardcopy version of the IAEA publication Quality Assurance for Screen Film Mammography.
For information on purchasing a hardcopy, please click here.
3. Radiographer test
The tests provided in the IAEA QA document form a QC programme for the radiographer. This programme does not include maintenance or calibration procedures. Maintenance and calibration activities should be performed by the appropriate individual according to the manufacturer’s instructions.
A brief description of the methodology to be undertaken when performing the radiographer’s QC tests is provided. The order in which tests are performed does not necessarily have to be that in which they appear in this document. The preferred order will depend on various factors relating to the mammography facility as well as the preferences of the individual performing the testing, always having in mind that the results of one test may affect the execution of others.
Radiographer data collection sheets can be found in Annex 1 of the Quality Assurance Programme for Screen Film Mammography (IAEA)
4. Medical physics tests
The tests provided in the IAEA QA document form a QC programme for the medical physicist. In addition to periodic testing, all tests should be performed at commissioning, i.e. before the equipment is initially used to image patients. Some commissioning tests are necessary to set up the base line values needed for the radiographer QC tests. In some cases, the medical physicist may also be responsible for performing some of the tests described in the section on radiographer’s tests.
Medical Physicist data collection sheets can be found in Annex 2 of the Quality Assurance Programme for Screen Film Mammography (IAEA)
The appendices give practical advice on subjects such as mammography room design, darkroom design, automatic processors, and areas of sensitometry.