Relevance: Breast cancer is one of the most common types of cancer among women worldwide and despite significant efforts in the field of diagnosis and treatment, remains a serious medical problem. According to GLOBOCAN, in 2022, more than 2.3 million new cases of breast cancer were registered, while the mortality rate from breast cancer was 669,846, which ranks fourth in terms of mortality among all malignant neoplasms [1]. In Kazakhstan, the incidence of breast cancer in 2022 amounted to 5,171 cases, ranking first among malignant neoplasms of all sexes and ages, and the mortality rate was 1,060, amounting to 8.1% [2].

For more than 10 years, screening for early detection of breast cancer from 40 to 70 years of age has been carried out once every 2 years in Kazakhstan. Digital mammography is the gold standard in breast cancer screening, however, despite the effectiveness of mammography, one of its main disadvantage is its limited sensitivity in women with dense breast tissue [3, 4]. Therefore, MR mammography is the method of choice for diagnosis in women with high density of mammary tissue. 

Magnetic resonance imaging has advantages in detecting small foci (from 4-5 mm), assessing retromammary tissue and axillary region, which are not determined by mammography. Due to the high specificity and sensitivity, MRI gives much more accurate images, therefore it is widely used before surgery, which allows you to completely remove cancerous tumors and avoid relapses.

Objective: to evaluate the role of MRI in the differential diagnosis of breast malignancies. 

Materials and methods: in the hospital of the Medical Center of the Office of the President of the Republic of Kazakhstan from January 2015 to January 2024, a total of 274 women aged 19 to 82 years were examined. Among them, 54 (19.7%) women showed signs of malignant neoplasm and pathomorphologically verified breast cancer. In total examined 4 patients up to 35 years old, 21 patients from 36 to 45 years old, 15 patients from 46 to 55 years old, 14 patients from 56 years and older.

These patients underwent MR mammography on a Magnetom Skyra Siemens 3.0 Tesla device using the contrast agent gadovist 7.5ml, calculated in a dosage per body weight of 0.1ml/kg. 

Results: The MRI data evaluated according to the standardized BI-RADS scale (Breast Imaging-Reporting and Data System) according to the degree of presence of breast malignancies and by type of density according to ACR (American College of Radiology).

BI-RADS 4 was exposed to 30 (55.6%) women with suspected breast cancer and a fine needle aspiration biopsy under ultrasound control was recommended.

BI-RADS 5 was exposed to 3 (5.6%) women, trepan biopsy under ultrasound control or in the presence of microcalcinates stereotactic trepan biopsy under mammography control was recommended.

BI-RADS 6 was exposed to 21 (38.8%) women, of which 15 women had pathomorphologically verified breast cancer, and 6 women underwent MRI to assess the prevalence malignancy of the process. Pathohistological findings include invasive carcinoma in 5 women, infiltrative carcinoma in 5 women, and intracurrent carcinoma in 5 women.

According to ACR, type A was detected in 5 (9.2%) women, type B in 23 (42.6%) women, type C in 9 (16.7%) women, type D in 17 (31.5%) women.

Conclusion: MR mammography is not a screening method for detecting primary cancer, given the high cost and duration of the diagnostic procedure. However, MRI with dynamic contrast is an important additional and most sensitive method for evaluating mammary glands in the presence of contraindications to X-ray methods, in cases where difficulties arise in interpreting the data of traditional mammography and ultrasound, for example, with a dense structure of the breast, in the presence of mutations in the BRCA1/BRCA2 genes, the presence of implants (if it is impossible to perform high-quality mammographic examination), in the presence of lobular cancer, postoperative scarring, and also after chemo-radiation therapy. Its high sensitivity and specificity makes it possible to evaluate not only the structure of the mammary glands, but also the surrounding soft tissues and the degree of damage to the chest wall, making it a valuable tool for early diagnosis of malignant changes.