Overview of the Ultrasound Classification Systems in the Field of Thyroid Cytology

SIMPLE SUMMARY: Ultrasound (US) is the preferred imaging modality for thyroid nodule evaluation. Accurate US assessment of thyroid lesions can help decrease unwarranted FNA procedures of benign nodules. Several thyroid nodule risk classification systems that focus on US features have been published. Some of them highlight simple US patterns, while others rely on the presence of multiple US features to categorize thyroid nodules. The current review offers an evaluation of different US system, combining them with the use of fine needle aspiration and the cytological classification systems. ABSTRACT: The increasing application of ultrasound (US) in recent years has led to a greater number of thyroid nodule diagnoses. Consequently, the number of fine needle aspirations performed to evaluate these lesions has increased. Although the majority of thyroid nodules are benign, identifying methods to define specific lesions and tailor risk of malignancy has become vital. Some of the tools employed to stratify thyroid nodule risk include clinical factors, thyroid US findings, and reporting systems for thyroid cytopathology. Establishing high concordance between US features and cytologic diagnoses might help reduce healthcare costs by diminishing unnecessary thyroid procedures and treatment. This review aims to review radiology US classification systems that influence the practice of thyroid cytology.