Breast Ultrasound: Mammary Sonography

Mammary ultrasonography (synonyms: breast ultrasound; breast ultrasound examination) is a medically and scientifically recognized examination of the mammary gland using ultrasound waves. It is used for the diagnosis of tissue changes in the mammary glands.The procedure is used for the early detection of malignant (malignant) breast tumors and the diagnosis of mastopathic changes in the female breast. Mastopathy refers to a variety of proliferative or degenerative remodeling processes of the mammary gland parenchyma (breast tissue), the causes of which are diverse.In addition to the sonographic examination of the breast, mammasonography always includes the examination of the axilla (armpit). Notice: The current German “S3 Guideline for the Early Detection, Diagnosis, Therapy, and Follow-up of Breast Cancer,” September 2018, emphasizes, “As the sole method for early breast cancer detection, the systematic use of sonography cannot be recommended. “Furthermore, “As part of complementary supplementary diagnostics, the use of sonography can lead to an increase in sensitivity, especially in women with an increased risk of breast cancer, < 50 years of age, and with dense glandular tissue.”

Indications (areas of application)

Breast ultrasonography is recommended as part of complementary diagnostics:

For prevention

  • Early detection and screening – especially in patients at increased risk of breast cancer:
    • If close relatives – mother, sisters, aunts – have breast cancer.
    • Women with BRCA mutation (biannual medical palpation and sonography and an annual magnetic resonance imaging (MRI)).
    • High mammographic density of the glandular body.
    • In patients with mastopathy
    • In the case of childlessness – 1.5 to 2.3 times increased risk of breast carcinoma

For diagnostics

  • In case of carcinophobia (pathologically exaggerated fear of own cancer).
  • Mastitis (inflammation of the breast) incl.an inflammation in the axilla (armpit).
  • Mastodynia (cycle-dependent feelings of tension in the breasts or breast pain).
  • In any change in the mammary gland – such as lumps, swelling, painfulness, galactorrhea (abnormal breast milk discharge).
  • During pregnancy and lactation
  • As an additive method, in patients in whom microcalcifications, cysts or other unclear changes have been found during mammography
  • For follow-up, i.e., in patients who have already had breast cancer.
  • For targeted cyst drainage in fluid-filled cyst formation.
  • In patients in whom a biopsy (tissue sample) has revealed microscopic signs of increased risk of degeneration
  • Follow-up of findings classified as benign (benign) that do not need to be extirpated (surgically removed) but observed.
  • For therapy control in preoperative chemotherapy for breast carcinoma.
  • To determine the size of the tumor (due todecision whether a breast carcinoma can be removed breast-conserving).
  • To determine the regional lymph node status (axilla sonography).

Contraindications

Due to the sound waves used, mammary sonography is absolutely free of side effects and harmless and can be repeated as often as desired. The only thing to pay attention to is an intact skin surface, so as not to cause pain or contamination of larger wounds.

Before the examination

Mammary sonography is always preceded by a medical history (taking of the patient’s medical history), especially with a focus on family history, and a clinical examination of the breast. The examining physician assesses the shape of the breasts and looks for visible irregularities. Furthermore, an orienting palpation (palpation) of the breast is an obligatory part of the examination. A change in the structure or, for example, the firmness of the breast tissue can often already be detected. Both clinical examination and sonography are always performed on both breasts and both axillae.

The procedure

During sonography, the patient lies on her back and puts both hands behind or above her head.Mammary sonography is performed using ultrasound waves, which differ from normal sound in that they have a different frequency of oscillation. High-resolution broadband linear probes with a frequency of at least 7.5 MHz are used.The ultrasound waves are reflected back differently at the boundaries of different body tissues and made visible on a screen. The procedure is called B-scan sonography (B-mode; B for brightness modulation; B-scan sonography), in which the gray tones are reproduced as a two-dimensional image. In addition, a color Doppler is usually used. This can record flow measurements of the blood flow in the blood vessels, providing information about the vascular richness and thus the dignity of a nodule (biological behavior of tumors; i.e., whether they are benign (benign) or malignant (malignant)). The vascularity of a nodule is thereby rendered as a color-coded signal.During the examination, a transparent gel containing water is applied to the breast to optimize the conduction of ultrasound waves into the breast tissue and back again. The transducer is moved over the breast with gentle pressure. Care must be taken to keep the transducer in a vertical position. In addition to assessing large-scale changes in the breast tissue, e.g. in the case of mastitis (inflammation of the breast), the examination serves to detect so-called focal findings: This refers to connective tissue or cystic changes that are distinct from the rest of the breast tissue, can be delineated and circumscribed, and can be visualized in two planes. There are numerous criteria for the evaluation of these focal findings, which can indicate benign or malignant findings. The following is an exemplary list of some criteria:

  • Shape – An irregular shape is among the typical findings of a malignant focus.
  • Alteration of the surrounding tissue
    • A malignant tumor often grows in a star shape and invades its surroundings (infiltration).
    • A benign tumor is more likely to displace surrounding tissue.
  • Tumor axis – The tumor axis describes the shape of the extent of the focal finding; a vertical axis may represent a malignancy criterion.
  • Rim – Rim is the term used to describe the edge and immediate surroundings of the tumor.
    • A narrow, circumscribed rim is indicative of a benign tumor.
    • An echo rich rim is among the typical findings of a malignant focus.
  • Echogenicity (reflection or scattering properties of a structure to sound waves) and internal echoes – Echogenicity describes the representation of the focal finding in the sonographic image and does not initially provide information about the dignity (biological behavior of tumors; i.e., whether they are benign (benign) or malignant (malignant)) of a finding.
    • A mammary cyst shows a circumscribed, homogeneous, and hypoechogenic structure; in some circumstances, the lobulated structure and a thin capsular boundary are visible.
    • So-called internal echoes are indications of the structure of the finding; malignant tumors often show a coarse internal echo (= inhomogeneous-echo-poor internal structure).
    • Dorsal acoustic extinction is among the typical findings of a malignant focus.
  • Compressibility and displaceability – Both signs indicate the benign nature of a tumor.

As soon as a finding is noticeable, it must be documented by the examiner, for example, by a printout of the ultrasound image. Any conspicuous focal findings or palpable tumor must be examined by a histological evaluation (biopsy), unless it has been documented and already clarified. A sonographic finding in combination with a palpable (palpable) finding is usually also followed by a mammographic examination.

Advantages of mammary sonography over mammography

  • Very good assessability of dense glandular tissue – e.g., in young women or postmenopausal women receiving hormone therapy
  • Repeatable as often as desired without hesitation;; furthermore, will be/are by a complementary mammasonography:
    • Raised the limited sensitivity (percentage of diseased patients in whom the disease is detected by use of the test, i.e., a positive test result occurs) of mammography at a “high mammographic density (ACR III and IV).
    • Tumors detected at an earlier stage; most (78%) of the tumors found only on ultrasound were invasive and lymph node negative
  • Dynamic assessability (“in real time”) of tissue changes.
  • Possibility of intervention – e.g. targeted fine needle biopsy under ultrasound control.
  • Gentle, low-radiation procedure
  • Very good distinguishability of different tissue structures – facilitates, among other things, tumor diagnostics.

Advantages of mammography compared to breast sonography

  • Established screening method for early detection of breast carcinoma.
  • Very good standardizability
  • The quality of performance of the procedure, unlike mammary sonography, is not primarily dependent on the skills and experience of the examiner.
  • The quality of the procedure is not as strongly dependent on the device as in mammary sonography.
  • Reliable representation of the so-called microcalcifications, which can be an important indication of malignant (malignant) disease of the mammary gland.

Other indications

  • An evaluation of 6,000 mammograms combined with breast ultrasonography in nearly 3,400 women compared with 15,000 women with approximately 30,000 mammograms without additional breast ultrasonography led to the following results: Cancer detection rates were similar in both study groups, at 5.4 versus 5.5 per 1,000 images. This was also true for the interval cancer rate, at 1.5 versus 1.9 per 1,000 images.

Benefit

Mammary sonography is a harmless and valuable diagnostic complementary procedure. Malignant diseases can be detected safely and treated in time.