THYROID NODULES CLASSIFIED AS ACR TI-RADS 4 AND 5

A PICTORIAL ESSAY

Abstract

OBJECTIVE: The Thyroid Imaging Reporting and Data System, published by the American College of Radiology (ACR TI-RADS) is a risk stratification and categorization system for ultrasound (US) findings of thyroid nodules. By this system, the nodules are classified into five categories, according to morphological characteristics, the last one having the greatest potential for risk of malignancy, that is, it has an increasing pattern of severity. The objective is to present sonographic images of thyroid nodules classified as moderately and highly suspected of malignancy, ACR TI-RADS 4 and ACR TI-RADS 5, respectively. METHOD: This is a pictorial essay with a collection of original images from the database of a diagnostic imaging center in the city of São Paulo. Eligibility criteria were: nodules classified as ACR TI-RADS 4 and 5, therefore, with moderate and high degree of suspicion for malignancy and recommendation of aspiration puncture for cytological evaluation. RESULT: The evaluation of the nodules and their characteristics evidences the morphological variability of thyroid nodules whose ACR TI-RADS classification can be moderately and increasingly suspicious of malignancy. In this way, it helps the attending physician to take the most appropriate course of action, which can be: expectant in relation to the nodule; perform ultrasound control or indicate a fine needle aspiration for cytological analysis of the nodule. CONCLUSION: This system seeks to simplify the interpretation of images obtained by radiologists, which is a valuable, safe and widely available imaging tool, in addition to being easily reproduced to stratify the risk of thyroid injury and help to avoid unnecessary invasive procedures.