With no moving along the transducer's long axis or perpendicular to the long axis, the compression should be uniform and as near to vertical to the skin as possible. Elastograms produced by sliding movements are noisy and of poor quality. As greater pressure is applied, the soft tissues will appear stiffer because biological tissue deforms non-linearly. As a result, there should be minimal pre-compression and lots of gel application with the transducer held gently barely in contact with the skin. Thetissuedisplacementsdeterminedfrom the received high-frequency data (RF)bycomparingsuccessive frames usingthesoftwareintercorrelation method. The resulting strain data is graphically displayed as a two-dimensional map called an elastogram. Elastograms are typically displayed as translucent overlays on grayscale images, using color-coded scales that can vary between US systems [39]. Someusers prefer to use red to signify stiffness (indicating danger or alarm) and blue to signify softness, while others have chosen the opposite. Given the importance of malignant lesions, most elastographic studies of thyroid tissue have focused on nodular pathology and the distinction between malignant and benign nodules. SE proved to be useful in the evaluation of thyroid nodules being an additional method, adjunct to ultrasonography in differentiating malignant from benign nodules [40; 41; 42; 43]. The EFSUMB guidelines on SE state that the method may be considered, in the hands of specialists, as a beneficial addition to US, increasing its accuracy for thyroid cancer identification [44]. It was found that SE can be used with good specificity and high sensitivity to detect malignant thyroid nodules [45]. Every elastographic technique has the common limitation that requires experience to obtain repeatable and accurate elasticity readings. Pre-stress can generate misleadingly high stiffness values, especially in superficial tissues. The fibrotic-atrophic involution that occurs in all types of thyroid nodules, whether benign or malignant, is a significant general constraint in the measurement of thyroid nodule elasticity. The presence of carotid artery pulsations in the thyroid gland, which causes compression-decompression movementsis a special limitation of thyroidelastography [46]. Non-invasive techniques are preferable, especially when frequent evaluations are required. One such efficient and trustworthy technique for evaluating the thyroid in adults is elastography. Children, however, are different from adults. The measurement reproducibility and diagnostic accuracy in the pediatric population can be influenced by several variables, including age and breath holding. There are also some studies on the usefulness of strain elastography in the differentiation of autoimmune thyroid diseases [47; 48], but on smaller groups of patients, leaving the possibility of new research directions. Although important, CAT has not been sufficiently studied in the pediatric population. Thus, our study proposes the elastographic evaluation of thyroid parenchyma affected by CAT in children. We aim to determine if there are significant differences between the level of elasticity of the thyroid parenchyma in children affected by CAT compared to healthy ones, as well as establish a cut-off value for the diagnosis of HT.