FNAC	fine-needle aspiration cytology
PPV	positive predictive value
NPV	negative predictive value
CAD	computer-aided diagnosis
ECI	elasticity contrast index
DL-CAD	deep learning-based computer-aided diagnosis
K-TIRADS	Korean Thyroid Imaging Reporting and Data System
SD	standard deviation
ROC	receiver operating characteristic
AUC	area under the curve
CI	confidence interval
SE	standard error