Purpose. Determination of the capabilities of a complex of ultrasound techniques and technologies for the differential diagnosis of thyroid follicular neoplasms.

Materials and methods. A retrospective open-blind cohort study was conducted. We studied the data of preoperative examination of 222 patients with follicular thyroid tumors: 86 patients with adenomas (FA) and 136 with follicular cancer (FC). The results of ultrasound examination of the thyroid (US) are analyzed. Emphasis was placed on identifying and evaluating signs that could indicate malignancy of the process. The study compared thyroid cancer risk stratification systems based on subjective pattern assessment (EU-TIRADS - European Thyroid Imaging and Reporting Data System) and computer image processing (TLA_RU - Thyroid Lineal Analisis_Russia). The criterion of truth was considered to be the results of morphological studies performed in the studied cohorts of patients. For evaluation, systematization and processing, the combined data of ultrasound and morphological studies were entered into the original database (certificate no. 2018621306 dated 16.08.2018).

Results and discussion. According to the evaluation system of US thyroid nodules, 21 cases (24.4%) of thyroid nodules were associated with EU-TIRADS2, 4 (4.7%) with EU-TIRADS3, 50 (58.1%) with EU-TIRADS4a, 11 (12.8%) with EU-TIRADS4b. According to the EU-TIRADS system, only 25 cases (24.4%) were followed-up without performing FNA. According to the TLA_RU system, the computer assigned 15 cases (17.4%) of follicular adenoma thyroid nodules to TLA_RU1 (high probability of a benign process), and 71 (82.6%) to TLA_RU2 (high tumor risk).

According to the evaluation system of US thyroid nodules, specialists regarded 4 cases (2.9%) as EU-TIRADS3, 9 (6.6%) as EU-TIRADS4a, 40 (29.4%) as EU-TIRADS4b, 83 (61, 0%) as EU-TIRADS5. According to the TLA_RU system, all cases of thyroid nodules risk factors were related to TLA_RU2.

The analysis of variance with the isolation of ultrasound signs and the assessment of their validity and rank in the rating system was carried out for a comparative assessment. The study showed that significant differences in nosologies exist only for 11 out of 15 signs and their diagnostic power is different. The diagnostic value of ultrasound signs based on the data of variance analysis of using multiple comparison (Multiple Comparisons) was established.

The performed ROC analysis showed that in the diagnosis of follicular neoplasms, the TLA-RU system reliably has a number of advantages over EU-TIRADS, primarily higher specificity.

Conclusion. Statistical evaluation of images obtained using various methods and technologies of ultrasound expands the capabilities of the method, improves the differential diagnosis of follicular neoplasms of the thyroid gland, and allows you to plan further diagnostic and therapeutic measures. Systems that reduce the subjectivity factor of evaluations are more promising in diagnostic terms.