First experience of comparisons between two different shear wave speed imaging systems in differentiating malignant...

The purpose of this study was to comparatively evaluate the two different shear wave speed (SWS) imaging systems of Toshiba shear wave elastography (T-SWE) and SuperSonic SWE (S-SWE) in distinguishing malignant from benign thyroid nodules (TNs).

140 patients with 140 focal TNs were enrolled and underwent T-SWE and S-SWE before fine-needle aspiration (FNA) biopsy or surgery. SWE indices of mean, standard deviation and maximum values (E-mean, E-SD and E-max) of elastic modulus in TNs were measured on a color-coded mapping. The receiver operating characteristic (ROC) curve was performed to assess the diagnostic performance.

Of the 140 nodules, 47 were thyroid carcinomas and 93 were benign. Areas under the receiver operating characteristic curve (AUC) were the highest with E-max among the three SWE parameters both for T-SWE and S-SWE (0.816 and 0.799). The most accurate cut-off values, sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were 26.6 kPa versus 42.9 kPa, 83.0% versus 63.8%, 68.8% versus 88.2%, 72.9% versus 80.0%, 56.5% versus 73.2% and 88.7% versus 82.8% with E-max for T-SWE and S-SWE, respectively. Among these comparisons, the sensitivity in T-SWE was statistically higher than S-SWE (83.0% versus 63.8%, p = 0.022), whereas specificity was statistically lower than S-SWE (68.8% versus 88.2%, p < 0.001).

T-SWE is equal to S-SWE with comparable and promising results for diagnosis of TNs. In clinical using, the selection of E-max should be recommended both for T-SWE and S-SWE.