Diagnostic ultrasonography study on thyroid nodules

Objective To study the effectiveness of conventional ultrasonography(US) and color Doppler flow imaging(CDFI) in differentiation of malignant and benign nodules of thyroid gland. Methods One hundred and fifty three consecutive patients with thyroid nodules who were to undergo surgery were examined before thyroidectomy by US and CDFI. The vascular pattern on CDFI was classified as follows: TypeⅠ,absence or little blood flow; Type Ⅱ, rich perinodular blood flow,absence or little inside; Type Ⅲ, marked intranodular and perinodular blood flow. Results On histology, 87 cases(263 nodules) were diagnosed as benign and 66 cases(109 nodules) as malignant. There was no correlation between solitary or multiple thyroid nodules and incidence of thyroid cancer. Differences of the US characteristic between the benign and malignant nodules of thyroid gland showed statistical significance (p 0.05 ). Malignant nodules were more often ill defined, hypoechogenic, solid, irregular, absent of halo sign and contain microcalcification. The Type Ⅲ pattern on CDFI was more often found in malignant nodules while the Type Ⅰ and Ⅱ pattern were more often found in benign ones(P 0.001 ). Conclusions The detection and differential diagnosis of thyroid nodules by ultrasonography is clinically valuable. The combination of conventional US characteristic and vascular pattern on CDFI in thyroid nodule can improve the accuracy of differential diagnosis.