OBJECTIVES:

To explore the potential added value of dynamic contrast enhanced ultrasound (DCE-US) using VueBox® software for the diagnosis of small solid thyroid nodules (≤1.0 cm).

PATIENTS AND METHODS:

This prospective study was approved by the institutional review board and it was performed at two hospitals from January 2020 to October 2020. B mode ultrasound and contrast enhanced ultrasound (CEUS) images were obtained for 79 small solid thyroid nodules (≤1.0 cm) confirmed by ultrasound-guided fine needle aspiration cytology results in 79 consecutive patients (55 women and 24 men, median age: 41 years). The CEUS time-intensity curves (TICs) of thyroid nodules and surrounding parenchyma were created by VueBox® software (Bracco, Italy). The CEUS quantitative parameters were obtained after curve fitting. The diagnostic performance of CEUS and DCE-US was evaluated and compared. The weighted kappa statistic (κ) was performed to assess the interobserver agreement and consistency between the diagnosis of CEUS and DCE-US.

RESULTS:

Among the 79 thyroid nodules, 56 (70.9 %) were malignant and 23 (29.1 %) were benign lesions. Hypoenhancement during the arterial phase of CEUS was associated with malignancy (P < 0.001), with an AUC of 0.705 (sensitivity 71.4 %, specificity 69.6 %). Among all CEUS quantitative parameters, the peak enhancement (PE), wash-in rate (WiR), and wash-out rate (WoR) of DCE-US in malignancies were significantly lower than those in benign nodules (P = 0.049, P = 0.046, and P = 0.020, respectively). The area under the receiver operating characteristic curves (AUCs) of PE, WiR, and WoR were 0.642 (sensitivity 65.2 %, specificity 67.9 %), 0.643 (sensitivity 43.5 %, specificity 91.1 %), and 0.667 (sensitivity 69.6 %, specificity 69.6 %) in differentiation between benign and malignant small solid thyroid nodules (≤1.0 cm), respectively. Comparing the quantitative parameters of DCE-US between small solid thyroid nodules and surrounding normal thyroid parenchyma, the PE, WiAUC, WiR, wash-in perfusion index (WiPI), WoAUC, WiWoAUC, and WoR of the nodules were significantly lower than those of normal thyroid tissue (P = 0.008, P < 0.001, P = 0.037, P = 0.009, P = 0.003, P = 0.002, P = 0.049, respectively). A total of 16 (20.3 %) nodules showed isoenhancement during the arterial phase of CEUS, while the median PE ratio of surrounding tissue and thyroid nodules was 1.70 (IQR: 1.33–1.89).

CONCLUSIONS:

VueBox® is a helpful tool for the evaluation of dynamic microvascularization of thyroid nodules, and DCE-US using VueBox® perfusion analysis could provide added values for differential diagnosis of small solid thyroid nodules (≤1.0 cm).