VueBox? perfusion analysis of dynamic contrast enhanced ultrasound provides added value in the diagnosis of small thyroid nodules

OBJECTIVES: To explore the potential added value of dynamic contrast enhanced ultrasound (DCE-US) using VueBox (R) 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 (R) software (Bracco, Italy). The CEUS quantitative parameters were obtained after curve fitting. The diagnostic performance of CEUS and DCE-USwas evaluated and compared. The weighted kappa statistic (kappa) 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, andWoR 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 (R) is a helpful tool for the evaluation of dynamic microvascularization of thyroid nodules, and DCE-US using VueBox (R) perfusion analysis could provide added values for differential diagnosis of small solid thyroid nodules (<= 1.0 cm).