Before purchasing mammography parts, it is important to know what type of mammography system your medical facility uses. Mammography x-ray systems are specially designed to produce radiographic images of the breast. This equipment is assembled of unique mammography parts, customized to produce the best images, with the minimal possible amount of exposure to x-ray radiation.
There are currently there are two main directions of development in the mammography field:
- Tomosynthesis – thin slices and 3D images of the breast are obtained and the breast is compressed in a standard way. While holding the breast stationary, the x-ray tube mammography part is rotated over the limited angular range. A series of low-dose exposures are made every degree or so, creating a series of digital images. The individual images represent projections through the breast at different angles and are reconstructed into slices.
- Computer-aided detection for mammography (CAD) – CAD is a computer-based process designed to analyze mammographic images for suspicious areas. In effect, it is a “second pair of eyes” for the radiologist. It is believed that CAD, when used for screening diagnostic mammography, can be a valuable procedure to aid in the early detection of breast cancer.
The main clinical applications of both of these types of systems are: breast cancer screening, staging and grading, and differential diagnosis in symptomatic patients.
Most types of mammographs allow magnification views and spot images. In general, mammographs are composed of mammography parts which have special ergonomic requirements, compared to those of the general radiographic systems.
A special stereotactic attachment, another critical mammography part, enables the performance of stereotactic biopsy procedures. The previous generation mammographs were all screen-film-types. A limitation of screen-film mammography is the film itself. Once a screen-field mammogram is obtained, it cannot be significantly altered. Contrast loss due to film underexposure, especially of dense glandular-tissues, cannot be regained through film display.
The latest mammography equipment features special mammography parts which are integrated, and as a result, digital mammography images can be obtained. Now, when the mammograph is in a digital format, the image can be manipulated in a variety of ways to highlight lesion conspicuity.
In addition, image storage, transmission and retrieval are improved. Digital images can be processed by a computer mammography part and displayed in multiple formats; on film or on a monitor. Computer-aided detection software to assist the radiologist in interpreting the images can also be used to provide a second opinion and improve diagnostic accuracy.
Digital mammography images can be obtained either by a full field of view (FFDM – full field digital mammography) a digital detector mammography part, or by using CR cassettes and a CR reader. Also, a small sized digital detector, another integral mammography part, can be incorporated into the film holder device mammography part, for image spotting and as a way of guiding stereotactic biopsies.
Small field digital mammography units are also available as add-on component mammography parts to the older screen-film mammographs. They can be used in conjunction with the mammography part stereotactic attachment. Digital imaging can be processed using sophisticated pattern recognition software, another vital mammography part, and suspicious features are highlighted on the image and brought to the attention of the reader. It is necessary to understand that the existing workflow will probably not work at a maximum efficiency once the department has moved to digital imaging. To achieve an efficient workflow, links to a PACS (Picture Archiving and Communications System) must be considered.
Reducing patient dosage to levels which are as low as reasonably practicable (ALARP) is both an ethical and legal requirement, falling under the Ionizing Radiation (medical exposure) regulations. There is a responsibility to reduce the long-term risks of radiation exposure (such as cancer reduction) to levels where the potential benefit of the examination outweighs the risk of any adverse effect. This is of particular importance in mammography, as the breast is a radiosensitive organ and mammography is currently the technique of choice for breast cancer screening, which results in a large number of disease-free women being imaged.
Some digital mammographs are based on a different approach: instead of using a flat panel detector mammography part, a scanning slot imaging geometry is used. A fan beam x-ray mammography part and a line of detectors, mechanically scan the breasts to acquire the mammographic data.
The mammographic system is integrated of a number of important mammography parts. The main mammographic parts are listed below:
The x-ray tube mammography part is the most important component of the system. It is responsible for the quality of the radiation. The target material (Mo, Mo/RH, Mo/W), the focal spots sized and the power of the tube are of prime importance.
The x-ray filter type is also very important mammography part. It filters out the unnecessary components of the x-ray radiation, and improves the beam “quality”.
The generator, as a mammography part, supplies the power to the x-ray tube. The generator should match the tube.
Automatic exposure control system is a mammography part which automatically optimizes the electric parameters and sets the proper exposure.
Compression pads are mammography parts of various sizes to match the size and the shape of various shapes and sizes of breasts.
The full field digital detector (24 X 30cm) can be a very expensive mammography part. The image acquisition and reconstruction system is the mammography part which accesses the digital detector. It is capable of converting the digital data flow into high-resolution images.
The workstation is an important mammography part of the mammography system. The stereotactic biopsy attachment is the indispensable mammography part for taking biopsies of possibly abnormal tissue.
