Reproducibility of the Shear Wave Elastography in Thyroid Stiffness Assessment

16 patients with the normal thyroid (32 lobes) and 11 patients with the focal lesions (15 colloid nodules) were examined. Intra- and interobserver reproducibility of the shear wave elastography was assessed. Young’s modulus (kPa) (Emax and Emean) was measured by using Aixplorer scanner (Supersonic Imagine, France) with linear probe (4-15 MHz). All measurements were acquired by two operators with the same experience in ultrasound. Interobserver reproducibility in assessment of Emean for normal thyroid parenchyma was as follows: intraclass correlation coefficient - 0.85 (0.63-0.95) (95% confidence interval), Spearman rank correlation coefficient - 0.84 (P = 0.0001) and kappa - 0.58 (0.41-0.74); intraobserver reproducibility - 0.95 (0.86-0.98), 0.94 (P < 0.0001) and 0.73 (0.63-0.82), respectively. Inter- and intraobserver reproducibility of Emax for normal thyroid parenchyma - 0. 81 (0.53-0.93), 0.85 (P < 0.0001) and 0.54 (0.41-0.74); 0.95 (0.85-0.98), 0.89 (P < 0.0001) and 0. 61 (0.45-0.78), respectively. Interobserver reproducibility in assessment of Emean for colloid nodules - 0.93 (0.84-0.97), 0.85 (P < 0.0001) and 0.62 (0.47-0.77); Emax - 0.90 (0.77-0.96), 0.79 (P < 0.0001) and 0.55 (0.38-0.72), respectively. Study results show high reproducibility and agree ment in Young’s modulus measurements. Intraobserver reproducibility of Young’s modulus measurements for normal thyroid parenchyma and colloid lesions was higher than interobserver reproducibility. Inter- and intraobserver reproducibility of Emean measurements was higher comparing with Emax. All reproducibility results for normal thyroid parenchyma and nodules assessment gave comparable results.

1. ГОСТ Р 8.563-96 “Государственная система обеспечения единства измерений. Методики выполнения измерений”. Режим доступа: // http://standartgost.ru/g/%D0%93%D0%9E%D0%A1%D0%A2_%D0%A0_8.563-96, свободный. Загл. с экрана. 20.03.2015.

2. Choi S.H., Kim E.K., Kwak J.Y., Kim M.J., Son E.J. Interobserver and intraobserver variations in ultrasound assessment of thyroid nodules // Thyroid. 2010. V. 20. No. 2. P. 167-172.

3. Митьков В.В., Васильева А.К., Митькова М.Д. Механические (упругие) свойства предстательной железы при эластографии сдвиговой волны // Ультразвуковая и функциональная диагностика. 2012. № 6. С. 16-25.

4. Sebag F., Vaillant-Lombard J., Berbis J. et al. Shear wave elastography: a new ultrasound imaging mode for the differential diagnosis of benign and malignant thyroid nodules // J. Clin. Endocrinol. Metab. 2010. V. 95. No. 12. P. 5281-5288.

5. Monpeyssen H., Correas J.-M., Tramalloni J. et al. Shearwave elastography of thyroid nodules: correlations with cytological data: study about 157 patients // Ultrasound Med. Biol. 2011. V. 37. No. 8. P. S8-S9.

6. Bhatia K., Tong C.S., Cho C.C., Yuen E.H., Lee J., Ahuja A.T. Reliability of shear wave ultrasound elastography for neck lesions identified in routine clinical practice // Ultraschall Med. 2012. V. 33. No. 5. P. 463-468.

7. Shrout P.E., Fleiss J.L. Intraclass correlations: uses in assessing rater reliability // Psychol. Bull. 1979. V. 86. No. 2. P. 420-428.

8. Zhang Y.F., Xu H.X., He Y., Liu C., Guo L.H., Liu L.N., Xu J.M. Virtual touch tissue quantification of acoustic radiation force impulse: a new ultrasound elastic imaging in the diagnosis of thyroid nodules // PLoS One. 2012. V. 7. No. 11. P. e49094.

9. Grazhdani H., Cantisani V., Lodise P., Di Rocco G., Proietto M.C., Fioravanti E., Rubini A., Redler A. Prospective evaluation of acoustic radiation force impulse technology in the differentiation of thyroid nodules: accuracy and interobserver variability assessment // J. Ultrasound. 2014. V. 17. No. 1. P. 13-20.

10. Landis J.R., Koch G.G. An application of hierarchical kappa-type statistics in the assessment of majority agreement among multiple observers // Biometrics. 1977. V. 33. No. 2. P. 363-374.

11. Митьков В.В., Хуако С.А., Ампилогова Э.Р., Митькова М.Д. Оценка воспроизводимости результатов количественной ультразвуковой эластографии // Ультразвуковая и функциональная диагностика. 2011. № 2. С. 115-120.