Mammography technique

A radiographic image of the mammary gland can be obtained using X-ray and ultrasound examinations, computed tomography and magnetic resonance imaging. The main X-ray method is mammography.

Mammography is an X-ray examination of the mammary gland without the use of contrast agents.

X-rays are taken on X-ray machines specially designed for this purpose - mammographs. The power of their X-ray tubes is 19-32 kV, they have two focal spots with diameters of 0.3 and 0.1 mm. The tube anode is made of molybdenum, and the output window is made of beryllium. These design features are necessary to obtain a uniform beam of low-energy radiation and achieve differentiated images of breast tissue on the images.

Mammography is performed when the breast tissue is compressed. Images are usually taken in two projections - direct and oblique or direct and lateral. In addition to overview mammograms, targeted images of individual sections of the gland are sometimes necessary. Mammographs are equipped with a stereotactic device for puncturing the gland and collecting material for cytological or histological analysis.

Mammography is performed in the first phase of the menstrual cycle (from the 5th to the 12th day, counting from the first day of menstruation). Women in menopause can have images taken at any time. The radiation load during mammography does not exceed 0.6-1.210° Gy. There are no complications or pathological reactions during the examination. The risk of developing radiation-induced cancer of the gland (radiogenic cancer) is negligible. A priori, it is defined as 5-6 cases per 1 million examined, and with a latent period of 10-20 years. But spontaneous breast cancer occurs in 90-100 thousand women, and only thanks to periodic mammography about half of them can be saved from death due to cancer.

Digital mammography is very promising. Its advantages include reduced radiation exposure, better detection of small details of the gland structure, and the possibility of using it in automated communication and archiving systems. A mammogram is an important document that must be stored in its natural form or in the form of digital copies for subsequent retrospective analysis.

Mammograms clearly differentiate all structures of the mammary gland. The skin stands out as a uniform dark strip 0.5-2.0 mm wide. Under it is fatty tissue, the layer of which gradually expands from the areola to the base of the gland. Against the background of the tissue, shadows of blood vessels and Cooper's ligament (superior pubic ligament) are visible. The main part of the image is occupied by the image of connective tissue and glandular elements located in it. In young women, the glandular-connective tissue complex produces a shadow in the form of a triangle, facing the apex of the nipple and having convex contours. With age, the almost uniform and intense shadow of the "glandular triangle" becomes inhomogeneous due to light layers of fatty tissue. The climacteric and post-climacteric periods are characterized by gradual atrophy of the glandular tissue and its replacement with fat. The remnants of glandular and connective tissue remain for the longest time in the upper outer quadrant of the gland.

In addition to mammography, two methods of artificial X-ray contrasting have become widespread: galactography (synonyms: galactophorography, ductography of the mammary gland) and pneumocystography. Galactography is performed with discharge from the nipple. A solution of radiopaque substance is injected into the secreting milk duct under slight pressure through a needle and X-rays are taken. The images show the system of the lobar milk duct with its branches. They are used to judge the topography of the duct, the type of its branching, the patency of the ducts, their deformation, displacement, the presence of cystic cavities along their course and, most importantly, the presence of tumor growths in them - papillomas or intraductal cancer.

During pneumocystography, a breast cyst is punctured, its contents are sucked out (sent for biochemical and cytological examination) and air is introduced instead. The radiographs show the internal surface of the cyst, which allows detecting intracystic tumor formations. In addition, the introduction of air, provided that the fluid is completely removed from the cyst, is an effective treatment procedure.

The complex of radiological studies also includes radiography of the preparation obtained during stereotactic biopsy or open surgical biopsy of the mammary gland.

Ultrasound has become a great ally of mammography. Its simplicity, harmlessness, and the possibility of multiple repetition are well known. It is more effective than mammography in examining dense mammary glands in young women and in detecting cysts, as well as in examining regional lymph nodes (axillary, supraclavicular and subclavian, parasternal). Sonograms can be performed on pregnant women and women during lactation. Sonograms provide a fairly clear image of the structure of the mammary gland. If Dopplerography with color mapping is performed, it is possible to get an idea of the state of small blood vessels in the area of pathological formations. Puncture of the mammary gland is often performed under ultrasound guidance.

Doctors rarely use X-ray computed tomography of the mammary gland, mainly when examining retromammary tissues. However, magnetic resonance imaging has made a major contribution to the comprehensive diagnostics of mammary gland diseases. It helps in identifying small pathological formations, allows assessing their blood supply, and is indispensable in assessing the condition of the implant after mammary gland prosthetics.

Scintigraphy provides valuable data when it is necessary to differentiate benign and malignant tumors, since radiopharmaceuticals such as 99mTc-sesamibi accumulate specifically in cancerous tumors.

Unlike radiography and sonography, which characterize mainly the morphological structure of the mammary gland, thermography allows us to study its thermal field, i.e., to a certain extent, judge the bioenergetic processes occurring in it.

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