The diagnostic value of a new ultrasonographic method for the measurement of a taller-than-wide shape of benign and malignant thyroid nodules.

Abstract

To evaluate the diagnostic value of a new ultrasonographic method in the measurement of thyroid nodules with a taller-than-wide (TTW) shape. A total of 982 thyroid nodules were analysed, 571 of which were malignant thyroid nodules and 411 of which were benign nodules. Nodules were divided into two groups by size: Group A (<1 cm, n = 627) and Group B (≥1 cm, n = 355). The angle between the maximum diameter of each nodule and the horizontal axis was measured by image analysis software. The best cut-off value for distinguishing between benign and malignant thyroid nodules and the diagnostic accuracy of the new ultrasonographic method in the measurement of TTW shapes were determined by receiver operating characteristic (ROC) curve analysis. The cut-off value for distinguishing benign and malignant thyroid nodules was 44.5 degrees. The area under the ROC curve (AUC) was 0.849 (95% CI: 0.822~0.875), and the sensitivity and specificity of the diagnosis of malignant thyroid nodules were 86.9% and 84.4%, respectively. Regarding the angle between the maximum diameter and the transverse axis of the thyroid nodules, an angle greater than 45 degrees was a significant indicator of a diagnosis of malignant thyroid nodules. The AUC for distinguishing malignant from benign thyroid nodules with the new ultrasonographic method in the measurement of TTW shapes was higher than that with the first method (FM) in the whole group, Group A and Group B (respectively, 0.849 vs. 0.812, 0.853 vs. 0.808, 0.852 vs. 0.828). The diagnostic sensitivity of a TTW shape measured by the new ultrasonographic method for predicting thyroid malignancy was significantly higher than that measured by the FM in the whole group, Group A and Group B (respectively, 0.858 vs. 0.760, 0.764 vs. 0.669, 0.890 vs. 0.815). A TTW shape measured by our new ultrasonographic method showed superior performance for predicting thyroid malignancy.