To evaluate the diagnosis value of ultrasound guided core needle biopsy (CNB) of thyroid nodules based on large sample retrospective analysis.

From April 2009 to April 2011, 369 thyroid nodules from 355 patients underwent ultrasound guided CNB in our department and were included in our research. Final diagnosis was provided by surgical pathological results for malignant nodules or by at least 3 years follow up for benign nodules. Bethesda classification of fine needle aspiration was used for determination. The inconclusive rates of CNB were evaluated. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy and the receiver operating characteristic (ROC) curve of CNB were calculated. The correlations of CNB results with final diagnosis and ultrasound characteristics were summarized.

The inconclusive result occurred in 22 (6.0%) nodules. The sensitivity, specificity, PPV, NPV, accuracy and area under the ROC curve of CNB were 97.7%, 98.5%, 99.1%, 96.3%, 98.0% and 0.981±0.009 (95%CI 0.964-0.998).

Ultrasound-guided CNB had high rates of conclusive and accurate diagnosis in thyroid nodules. It could reduce repeat FNA, diagnostic surgery and unnecessary follow-up. US characteristics did not affect the diagnostic value of CNB. Ultrasound-guided CNB can also be served as the first-line diagnostic tool for thyroid nodules with suspicious Ultrasound- findings.