Preliminary study on the diagnostic value of acoustic radiation force impulse technology for differentiating between benign and malignant thyroid nodules

Abstract

Objectives-This study aimed to evaluate the diagnostic value of acoustic radiation force impulse (ARFI) elasticity imaging for differentiating between benign and malignant thyroid lesions. Methods-Hospitalized patients needing thyroid surgery were evaluated. After routine thyroid sonography, the patients underwent ARFI elasticity imaging. Virtual Touch tissue imaging (VTI) and Virtual Touch tissue quantification (VTQ; Siemens Medical Solutions, Mountain View, CA) were used to qualitatively and quantitatively analyze the elasticity and hardness of nodules. For statistical analysis, the Student t test, analysis of variance, and the X2 test were used to compare the elastic parameters. Results-Of the 98 thyroid nodules observed in 72 hospitalized patients, 56 were nodular goiters, 16 thyroid adenomas, 4 thyroiditis, and 22 thyroid malignancies, with mean VTQ values ± SD of 2.034 ± 0.484, 1.835 ± 0.364, 2.293 ± 0.787, and 3.941 ± 1.393 m/s, respectively. The elastic parameters of malignant nodules were significantly higher than those of benign nodules (P < .001) and the surrounding thyroid parenchyma (P< .001). There was no significant difference between the VTQ value of benign nodules and that of the surrounding normal thyroid parenchyma (P > .05). For differentiating between benign and malignant nodules, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accordance rate were 86.36%, 93.42%, 79.17%, 95.95%, and 91.84% based on the standard VTQ value (2.555m/s). In total, 77.6% (59 of 76) of the benign nodules showed softer and equal images in the VTI mode, and 77.3% (17 of 22) of the malignant nodules showed stiffer images (P < .001). Conclusions- Acoustic radiation force impulse imaging has high sensitivity and specificity in evaluating benign and malignant thyroid nodules and therefore had good diagnostic value in clinical applications. ©2012 by the American Institute of Ultrasound in Medicine.