Use of an Easily Applicable Thyroid Imaging-Reporting and Data System (TI-RADS): Our Kwak TI-RADS Experience

Background: Early detection of malignant thyroid nodules is possible using ultrasonography (US)-guided fine needle aspiration biopsy (US-FNAB), which is a minimally invasive and easily applicable method. There are several guidelines based on the US findings, including the Thyroid Imaging-Reporting and Data System (TI-RADS), to identify patients requiring FNAB or patients with nodules suspicious of malignancy. Objectives: To emphasize the importance of the easily applicable Kwak TI-RADS classification system. Methods: In this cross-sectional study, the radiological and pathological findings of 641 consecutive patients, who underwent US-FNAB in our center, were retrospectively evaluated. The relationship between the cytological/histopathological results and the US findings was investigated using univariate and multivariate analyses. The results were also compared with the data in the literature. Results: In the univariate analysis, US features, including the presence of a solid component, hypoechogenicity, microlobulation or irregular margins, microcalcifications, and a taller-than-wide shape, were significantly associated with malignancy (P < 0.05). However, in the multivariate analysis, only hypoechogenicity and a taller-than-wide shape significantly contributed to the diagnosis of malignancy (P < 0.05). The malignancy rates of TI-RADS 3, 4a, and 4b lesions were lower in the present study compared to the literature. Conclusions: The US features, including the presence of a solid component, microcalcifications, hypoechogenicity, microlobulation or irregular margins, and a taller-than-wide shape, must be evaluated during US examinations. Besides, the widespread use of Kwak TI-RADS classification system, similar to the Breast Imaging-Reporting and Data System (BI-RADS), should be encouraged to provide a common tool for clinicians and prevent unnecessary surgical procedures.