A Novel Two-dimensional Quantitative Shear Wave Elastography Mode for Differential Diagnosis of Benign and Malignant Thyroid Nodules

Background: To evaluate the diagnostic performance of a novel two-dimensional quantitative shear wave elastography (SWE) of virtual touch tissue imaging quantification (VTIQ) in the differential diagnosis between benign and malignant thyroid nodules.Methods: Two hundred and six solid thyroid nodules were included in this prospective study. Conventional ultrasound and VTIQ examinations were performed. The diagnostic performances of US, VTIQ, and the combination of the two methods were compared. The usefulness of VTIQ in different size of nodules was also assessed.Results: There were 113 benign nodules and 93 malignant nodules on fine needle aspiration (FNA) or histology. The shear wave velocities (SWVs) in malignant nodules were all significantly higher than those in benign nodules (SWV max: 4.01 ± 1.72 m/s vs 3.25 ± 1.01 m/s, SWV min: 2.87 ± 0.69 m/s vs 2.46 ± 0.67 m/s, SWV mean: 3.33 ± 0.89 m/s vs 2.85 ± 0.81 m/s, SWV median: 3.31 ± 0.88 m/s vs 2.82 ± 0.77 m/s, all P value < 0.001). After combined VTIQ with ultrasound, the diagnostic performances improved compared with ultrasound alone or VTIQ alone. As for lesions of different sizes, areas under curve (AUC) for the largest diameter of nodules ≤ 1.0 cm was 0.711, which was lower than that for the largest diameter of the nodules > 1.0 cm (AUC was 0.862) (P < 0.05). Conventional ultrasound features such as halo sign and microcalcification were predictors for lymphatic metastasis in malignant thyroid nodules (P < 0.05).Conclusions: VTIQ is a new method for measuring stiffness of thyroid lesions qualitatively. The diagnostic performance of combined using VTIQ and conventional ultrasound was better than that of using either alone. Malignant thyroid nodules with conventional ultrasound features such as halo sign and microcalcification were more likely to have lymphatic metastasis. The evaluation of small thyroid lesions remained a difficult problem.