3-D Ultrasound and Thyroid Cancer Diagnosis: A Prospective Study

This study tests the hypothesis that evaluation of thyroid nodule (TN) margin irregularities by three-dimensional ultrasound (3-D-US) distinguishes benign from malignant TNs with greater sensitivity and specificity than two-dimensional ultrasound (2-D-US). We prospectively evaluated 344 TNs using both 2-D-US and 3-D-US followed by fine needle aspiration biopsy. TNs were divided into four groups based on the 3-D-US appearance of the margins. Bi-variate and multi-variate analyses were used. Surgical pathology confirmed 44 thyroid cancers in 40 patients. For 2-D-US, irregular margins and micro-calcifications (p < 0.001) were found more frequently in malignant TNs. Irregular margins on 2-D-US had a sensitivity and specificity of 61.4% and 79.3%, respectively. Irregular margins on 3-D-US had a sensitivity and specificity of 86.4% and 83.3%, respectively. Sensitivity, specificity, positive and negative predictive values were higher for irregular margins on 3-D-US than micro-calcifications and irregular margins on 2-D-US. Evaluation of TN margins by 3-D-US distinguished benign from malignant TNs with greater sensitivity and specificity than 2-D-US.