Objective To investigate the findings of contrast-enhanced ultrasound for papillary thyroid carcinoma and its pathological bases. Methods Seventy two (72) patients with thyroid nodules underwent routine conventional ultrasound and color Doppler examination, and 86 nodules with TI-RADS≥3 were examined by contrast-enhanced ultrasound (CEUS). Histopathological examination was kept as standard reference and the findings of CEUS were analyzed. Pathological studies of all nodules were made after post-operative CD34 immunohistochemistry staining examination. Results Of the total 86 nodules, Adler CDFI classification grades were: grade 0-26, grade Ⅰ-34, grade Ⅱ-23 and grade Ⅲ-3 nodules respectively. Enhancement pattern on CEUS showed that there was low enhancement on 71 nodules, iso-enhancement on 12 and high enhancement on 3 nodules. The differences of echo mean intensity, the peak intensity, area under the curve for enhancement intensity and CD34 count between the nodules and surrounding tissue were statistical significant (P
