Comparison of Ultrasonography and Computed Tomography Features of Calcified Thyroid Nodules

Abstract

Background: No previous studies have reported the direct comparison between Ultrasonography (US) and Computed Tomography (CT) features of Calcified Thyroid Nodules (CTNs). Objective: This study aimed to compare the patterns and types of CTNs examined by preoperative neck US and CT. Methods: From January to June 2011, 224 patients who underwent neck US and CT before thyroid surgery were included. Out of the 224 patients, 165 had a CTN showing a clear match on US and CT. The CTN patterns were classified as follows: peripheral, central, and combined. The CTN types were classified as follows: micro-, nodular, eggshell, curvilinear, pure, and mixed. Results: Out of the 165 CTNs in 165 patients, 143 were papillary thyroid carcinomas, 2 follicular thyroid carcinomas, 7 follicular adenomas, and 13 nodular hyperplasias. The most common CTN pattern on US and CT was combined and central, respectively, and a statistical difference was observed in the CTN patterns between US and CT (p < 0.0001). In the type of CTNs, the most common type on US was microcalcification (64.2%, 106/165), whereas the prevalence rate of punctate calcification on CT was only 9.1% (15/165). A statistical difference was observed in the type of CTNs between US and CT (p < 0.0001). Conclusion: US is superior to CT in the evaluation of microcalcifications, whereas macrocalcifications showed the different features between US and CT. Recognizing the different features of CTNs on US and CT may be helpful in the evaluation of thyroid nodules.