[Differential diagnostic value of contrast-enhanced ultrasound in calcified thyroid nodules]

To evaluate the diagnostic value of contrast-enhanced ultrasound(CEUS) in calcified thyroid nodules.

A total of 179 cases with calcified thyroid nodules between February 2009 and September 2012 underwent CEUS by injection of microbubbles via superficial vein was included in the study. Pathological diagnosis as a gold standard, the sensitivity, specificity, positive predictive, negative predictive and diagnostic coincidence rate of CEUS were evaluated.

Among 110 cases of benign nodules, 62 cases were nodular goiter (46 cases with macrocalcification and 16 cases with microcalcification); 29 cases were adenoma (28 cases with macrocalcification and 1 case with microcalcification); 17 cases were Hashimoto's thyroid (13 cases with macrocalcification and 4 cases with microcalcification); and 2 cases were granuloma with microcalcification. Among 69 cases of malignant nodules (t = 14.33, P < 0.05), 68 cases were papillary carcinoma (60 cases with microcalcification and 8 cases with macrocalcification), and 1 case of medullary carcinoma with microcalcification. Malignant nodules mainly showed weak inhomogeneous enhancement, with the mean; peak intensity (51.38 ± 14.33)dB that was lower than that (92.37 ± 33.36)dB in benign nodules, and benign nodules showed isoenhancement or hyperenhancement, with significant differences compared to malignant nodules (t = 14.33, P < 0.05) , however, there were significant differences in the enhanced time and the time to peak between benign and malignant nodules. The sensitivity, specificity, positive predictive, negative predictive and diagnostic coincidence rate of CEUS for the diagnoses of thyroid nodules were 92.75%, 90.91%, 86.49%, 95.24% and 91.62%, respectively.

CEUS has high value in differential diagnosis of benign and malignant calcified thyroid nodules.