Diagnostic value of CT combined with ultrasonography for benign nodules in thyroid gland
HUANG Ya-yuan1, BAO Ling-yun1, HAN Zhi-jiang1, SHU Yan-yan2, GU Ying1, LUO Ding-cun1
1． Department of Ultrasound, First People’s Hospital of Hangzhou City, Hangzhou Center for Diagnosis and Treatment of Thyroid Disease, Hangzhou 310006, China; 2． Department of Radiology, First People’s Hospital of Hangzhou Xiaoshan Area, Hangzhou 311200, China
Abstract：Objective: To investigate the diagnostic value of CT combined with ultrasonography(US) for the diagnosis of benign annular calcification nodules in the thyroid gland. Methods: Eighty-six annular calcification nodules in 75 patients whom were detected by CT and?蛐or US were confirmed by pathology were included in this study. According to the collected imaging data, the nodules were divided into 2 groups: Group 1: CT was not diagnostic for benign thyroid nodules(BNS): in which US showed annular calcification, but showed no ring-like calcification on CT. A long curved-like calcification was the characteristic US sign for BNS. US is ideal for diagnosing BNS in this group. Group 2: US was not diagnostic for BNS, as the posterior wall of the annular calcification was covered by acoustic shadow, but on contrast CT when the interior content of the annular calcification or the rim of calcification had obvious enhancement or even more obviously enhanced was the CT characteristic sign for BNS. The sensitivity, specificity of the characteristic CT sign, the characteristic US sign, and combination of the two characteristic sign for BNS were evaluated. In this study, 61 nodules were BNS, and 25 nodules were malignant nodules(MNS). The imaging features of BNS and MNS were also compared. Results: In 86 annular calcification nodules, group 2 can see 77 nodules, and group 1 can see only 9. Group 1 can see 69 nodules and 17 in group 2. In group 2, the CT characteristic sign seen in BNS was 77.2%(44?蛐57), while in MNS was 35%(7?蛐20), P＜0.05. In group 1, the characteristic US sign seen in BNS was 77.6%(38?蛐49), while in MNS was 10%(2?蛐20), P＜0.05. The sensitivity and specificity of characteristic CT sign for BNS were 77.2% and 65.0% respectively. The sensitivity and specificity of US characteristic sign for BNS were 77.6% and 90.0% respectively. The sensitivity and specificity of the combined characteristic sign of CT and US for BNS were 39.3% and 100% respectively. Conclusion: Either CT alone or US alone has advantages and disadvantages in diagnosing the nature of annular calcification, but combined using CT and US can significantly improve the specificity of benign annular calcification in BNS vs MNS, and thus reduce unnecessary fine needle aspiration or even surgical operation.
2014, Vol. 25 
