Application of Various Additional Imaging Techniques for Thyroid Ultrasound: Direct Comparison of Combined Various Elastography and Doppler Parameters to Gray-Scale Ultrasound in Differential Diagnosis of Thyroid Nodules

This study was conducted to evaluate the role in the differential diagnosis of thyroid nodules of various elastographic and Doppler parameters when added to gray-scale ultrasonography (US). One-hundred seventy-one thyroid nodules (63 malignant, 108 benign) in 169 patients were included. Elastography (strain and shear wave elastography) and Doppler (power Doppler, superb microvascular imaging and microflow imaging) images of the same thyroid nodule were obtained using a single US machine. The diagnostic performance parameters of gray-scale US with and without elastography and those of Doppler US were calculated and compared. The specificity, positive predictive value and accuracy of gray-scale US were significantly higher than those of US combined with elastographic parameters (all p values < 0.05). The area under the receiver operating characteristic curve for gray-scale US was 0.877, significantly higher than that for US combined with elastography patterns, shear wave elastography ratio (all p values < 0.05) and Doppler parameters. Adding additional imaging modalities such as elastography and Doppler does not improve the diagnostic performance of gray-scale US in differentiating thyroid nodules.