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Mammography is a high-definition, low-dose X-ray examination of the breasts. A mammography examination (mammogram) is used for the early diagnosis of breast cancer or other breast diseases.

Types of mammography

Mammograms can be digital or three-dimensional (3-D tomosynthesis).

Digital mammography differs from the conventional technique as it replaces the X-ray film with an electronic image of the breast that can be saved on a computer. Nowadays the majority of mammograms are digital and they offer the advantage of producing better images and at lower doses of radiation.

Tomosynthesis is used to capture 3D images and produce a three-dimensional, and therefore more realistic, representation of the breast. This latter technique has the advantage of creating a clearer picture of any injuries, their extension, size and location.

Computer-aided detection (CAD) systems use a digitalised mammogram that can be obtained through either conventional plain film or digital mammography. CAD software can search for and highlight any areas of irregular density, masses or calcifications that may indicate the presence of cancer.

How does it work?

Mammograms are obtained with X-rays that pass through the breast to produce an image. The images can be recorded in either a digital format or on a film. Different areas of the breast appear lighter or darker depending on their density. Although the patient receives less radiation, they are only recommended when absolutely necessary.

What is it used for?

Mammograms can be used in the early detection of breast cancer, to study new lesions and to diagnose breast diseases.

How is it performed?

Conventional mammograms are usually carried out with the patient in a standing position. A healthcare professional will place the breast in the mammography unit (on a tray) and squeeze it against a flat surface. This compression helps produce a clearer image of the tissues, in other words the breast adopts a more suitable shape allowing the machine to take the best possible images.

How do I prepare for a mammogram?

No special preparation is required. However, you do have to remove all metal objects (e.g., jewellery, piercings or other adornments) and attend the examination without any body cream, deodorant or talc under your armpits or on your breasts as these products can affect image quality.

If you notice any symptoms or discomfort during the test, you should tell the healthcare professional there to guide you through the whole process.

If you have already undergone a mammogram(s), you should give the results to the specialist as it is very important to make a comparison with previous studies. Patients should always keep their examinations. Both the test being carried out and the preparation with previous studies are important. Additionally, you should tell the doctor about any prior surgery, the use of hormones and any personal or family history of breast cancer.

It is recommended to perform the mammogram one week after menstruation as sometimes the breasts can be more sensitive during the process.

Special situations

Tell your healthcare professional in the following situacions:

  • Pregnancy. It's necessary to confirm your pregnancy and then assess whether the examination is appropriate.
  • Breastfeeding. They will have to assess whether a mammogram is the best option.
  • A recent operation or a strong blow. When you have been operated recently or received a strong blow to the breasts.
  • A breast implant. As the technique will have to be adjusted.
  • Under 35 years. The test is not recommended because breast tissue is very dense at this age and mammograms do not yield clear results. Patients in this age group usually start their study with an ultrasound test.

Who performs the test?

Healthcare professionals will guide and assist the patient throughout the test.

Who interprets the results?

A healthcare professional specialising in radiology and with specific training in the diagnosis of breast diseases.

What can I expect to feel during the test?

Patients do not generally feel anything. You may sometimes note a little discomfort due to the pressure applied, but only for a very short period. If you notice pain as the pressure increases then you should tell the healthcare professional.

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Substantiated information by:

Laura Oleaga Zufiría

Published: 20 February 2018
Updated: 28 October 2022


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