Strain Imaging in the Evaluation of Thyroid Nodules: The Associated Factors Leading to Misdiagnosis.

Abstract

This study analyzed which imaging characteristics may contribute to misdiagnosis of benign and malignant thyroid nodules (TNs) through strain imaging (SI). We analyzed SI parameters and conventional ultrasound (CUS) characteristics of 264 nodules with histopathology results and we applied binary logistic regression analysis to select independent variables for incorrect SI results. The elastography imaging (EI) score and the virtual touch tissue imaging (VTI) score of malignant TNs were remarkably higher than that in benign TNs. VTI, of which the false-positive rate (FPR), the false-negative rate (FNR), and the cutoff value were 47.6% (39/82), 17.6% (32/182) and 3.5, presented higher diagnostic performance than EI. Aspect ratio (odd ratio [OR]: 14.208) and intra-nodular calcification (OR: 20.384) were significantly associated with false-positive VTI findings, while posterior acoustic feature (OR: 30.424) was significantly associated with false-negative VTI findings. Sex (OR: 0.221) and aspect ratio (OR: 0.268) were negatively associated with false-negative EI findings. In conclusion, sex and aspect ratio significantly affect the accuracy of EI results, while aspect ratio, intra-nodular calcification and posterior acoustic features notably affect the accuracy of VTI results. These CUS features of TNs should not be ignored before explaining SI examination results.