[Evaluation of Extrathyroidal Extension of Papillary Thyroid Microcarcinoma With Three-Dimensional Tomographic Ultrasound Imaging].

Objective To evaluate extrathyroidal extension (ETE) in papillary thyroid microcarcinoma (PTMC) with three-dimensional tomographic ultrasound imaging (3D-TUI). Methods A total of 97 thyroid nodules of 79 patients with PTMC treated in PUMC Hospital from February 2016 to January 2018 were included in this study.Two ultrasound experts performed independent blinded assessment of the relationship between thyroid nodules and thyroid capsule by two-dimensional ultrasound (2D-US) and 3D-TUI.The results of 2D-US and 3D-TUI in evaluating ETE were compared with intraoperative findings and postoperative histological and pathological results. Results Among the 97 nodules,54 (55.7%) nodules had ETE.The diagnostic sensitivity (68.5% vs.37.0%;χ2=10.737,P=0.002),accuracy (74.5% vs.56.7%;χ2=6.686,P=0.015),and area under the receiver operating characteristic curve[0.761 (95%CI=0.677-0.845) vs.0.592 (95%CI=0.504-0.680);Z=3.500,P<0.001] of 3D-TUI were higher than those of 2D-US.However,3D-TUI and 2D-US showed no significant difference in the specificity (84.1% vs.81.4%;χ2=0.081,P=0.776),negative predictive value (67.9% vs.50.7%;χ2=3.645,P=0.066),or positive predictive value (84.1% vs.71.4%;χ2=1.663,P=0.240). Conclusion Compared with 2D-US,3D-TUI demonstrates increased diagnostic efficiency for ETE of PTMC.