Is the reproducibility of shear wave elastography of thyroid nodules high enough for clinical use? a methodological study

Autor: Rubeck, K. Z., Bonnema, S. J., Jespersen, M., Christiansen, P., Bibby, B., Nielsen, V. E.
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: Rubeck, K Z, Bonnema, S J, Jespersen, M, Christiansen, P, Bibby, B & Nielsen, V E 2015, ' Is the reproducibility of shear wave elastography of thyroid nodules high enough for clinical use? a methodological study ', Thyroid, vol. 25, no. S1, 798, pp. A315-A316 . https://doi.org/10.1089/thy.2015.29004.abstracts
Popis: Shear Wave Elastography (SWE) assesses tissue elasticity quantitatively (Elasticity Index, EI). A higher EI in malignant thyroid nodules has been reported, suggesting SWE as a potential tool for diagnosing thyroid malignancy. However, thyroid SWE needs to be further evaluated before clinical application is legitimate. Our aim was therefore to systematically assess the reproducibility of SWE, when applied to patients undergoing surgery for thyroid nodular disease. SWE examinations were performed pre-operatively in 52 patients [male/female: 13/39; mean age: 53 years (range 21-81); malignant/benign 13/39] referred to a tertiary thyroid center. Guided by at color-coded map, repeat registrations of EI in predefined regions of interest (ROIs) were performed for the index nodule by two independent investigators on the same day, and by one investigator on a different day. We assessed thyroid SWE reliability by calculating the inter- and intraobserver variation along with the day-to-day variation. Results are presented as 95% limits of agreement, by which a variation of 0% indicates perfect concordance between observations. Independent measurements for mean EI of 10mm ROI showed an inter-observer variation of 95%, whereas the intra-observer variation was 92% and 85% for the two observers, respectively. The day-today variation (n = 40) was 176%. Using mean EI for a 3mm ROI, measurements showed an inter-observer variation of 164%, while the intra-observer variation was 131% and 126% for the two observers, respectively. The day-to-day variation (n = 40) was 243%. When comparing EI measurements of 10mm ROI, a systematic interobserver difference of 18% (95%-CI: 9-29%, p = 0.0002) was registered, whereas no systematic difference was found for 3mm ROI (p = 0.38). In this methodological study of thyroid SWE, we found a suboptimal observer agreement, as measured by the 10mm ROI, and the variation was even higher by a 3mm ROI. In addition, a high day-today variation of EI raises concern, and may invalidate this method as a reliable tool for discriminating malignant from benign thyroid nodules.
Databáze: OpenAIRE