Untangling the ultrasound conundrum of microcalcifications in papillary thyroid cancer

Abstract

The Thyroid Imaging Reporting and Data System (TI-RADS) is a comprehensive system aiming to standardize interpretation and reporting of thyroid nodules on ultrasound (US) proposed by the American College of Radiology (ACR). 1 In a recent meta-analysis, Li and colleagues found that ACR TI-RADS showed moderate to high sensitivity and moderate specificity in risk stratification of thyroid nodules, avoiding a large number of unnecessary biopsies. 2This scoring system relies on the evaluation of five categories of US thyroid nodule features (composition, echogenicity, shape, margins, and echogenic foci) with an incremental score that is correlated to the likelihood of malignancy. 1,3 Regarding the US standardized classification of echogenic foci, the ACR TI-RADS suggests adopting a precise terminology including the following different patterns: large comet-tail artifacts, macrocalcifications, peripheral calcifications, and punctate echogenic foci (PEF). 4,5 Specifically, ACR TI-RADS defines PEF as "dot-like" foci which may be associated with small comet-tail artifacts but without posterior acoustic shadowing. 4,6 Accordingly, the use of the term