Value of conventional ultrasound combined with contrast-enhanced ultrasound in differential diagnosis of thyroid TI-RADS 3-5 nodules

Objective To evaluate the diagnostic value of gray-scale ultrasound combined with contrast-enhanced ultrasound (CEUS) in thyroid imaging and reporting system (TI-RADS) 3-5 nodules of American College of Radiology (ACR). Methods The 208 patients(216 nodules) who underwent thyroid contrast-enhanced ultrasound examination from April 2014 to December 2016 were retrospectively analyzed. The ACR TI-RADS classification and contrast-enhanced mode of thyroid ultrasound were evaluated. The benign and malignant thyroid lesions were constructed through the analysis of contrast-enhanced mode of thyroid benign and malignant lesions in the past literature and the preliminary study of our group. Prediction model of gray scale combined with contrast-enhanced ultrasound for lesions were established. Besides, the sensitivity, specificity and accuracy of gray scale ultrasound combined with contrast-enhanced ultrasound prediction model for differential diagnosis of benign and malignant thyroid lesions were calculated based on the results of puncture biopsy or surgical pathology as the gold standard. Results Compared with pathological results, the positive predictive value, negative predictive value, accuracy, sensitivity and specificity of gray scale combined with contrast-enhanced ultrasound in evaluating thyroid nodules were 90.8%, 93.3%, 91.2%, 98.8% and 62.2%, respectively. Conclusions Gray-scale ultrasound combined with contrast-enhanced ultrasound can provide clinical value in differential diagnosis of benign and malignant TI-RADS 3-5 thyroid nodules. Key words: Contrast-enhanced ultrasound; Thyroid nodule; Thyroid imaging reporting and data system