Biochemical and ultrasonographic parameters influencing thyroid nodules elasticity

Abstract

Elastography is a method of tissue stiffness assessment. It has already been demonstrated that thyroid cancers are less elastic than benign lesions. However, little is known about other factors, which might influence the stiffness of thyroid nodules and disrupt the prediction of malignancy using this technique. The aim of this study was to conduct the first systematic assessment of factors potentially affecting the elasticity of thyroid lesions. One hundred and twenty-two patients with thyroid nodular disease admitted for thyroidectomy underwent preoperative ultrasonography and sonoelastography. The definite diagnosis of thyroid lesions was based on histological examination. What was evaluated in the study was the influence of composition, size, localization, nodularity, and selected laboratory parameters on thyroid nodule elasticity. Firstly, association between the above-mentioned factors and elasticity was assessed in benign lesions. Secondly, all nodules (benign and malignant) were divided into subgroups according to the presence or absence of particular features, which turned out to be an important disturbing factor increasing the stiffness of the lesion in the first step of analysis. There were 22 malignant and 371 benign lesions. The analysis of benign lesions revealed that the presence calcifications (p < 0.0001) significantly increased nodule stiffness. Partially, cystic nodules were significantly less elastic than solid ones (p = 0.03). There was also positive correlation between nodule size and stiffness (p < 0.0001). Lesions localized in the isthmus were significantly less elastic than nodules in other localizations. (p = 0.0001). Solitary nodules were less elastic than lesions in multinodular goiter (p = 0.006). Correlation between Tg concentration and stiffness was significant (p < 0.0001, r = 0.24). The concentration of anti-thyroid autoantibodies was associated with stiffness at the border of significance. However, there was no significant difference between benign lesions in patients with diagnosed chronic autoimmune thyroiditis and patients without the disease. The analysis of the entire group of nodules revealed that shear wave elastography is a valuable modality of thyroid nodule assessment, with sensitivity of over 95 % and specificity of about 70 %. However, the stiffness value of the lesion might be increased in the case of nodules containing calcifications, cystic component, and those of size above 20 mm. Certain clinical conditions or attributes of the lesions influence the stiffness values of thyroid nodules. Identifying these variables is the basis for a credible interpretation of the results of a sonoelastographic examination and makes it possible to estimate the risk of thyroid nodule malignancy adequately.

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

“…Several internal and external factors may influence EI measurements, including characteristics of the nodule, structural interfaces between tissues, movement artefacts and the so-called vertical artefacts. 15,[19][20][21][22] Operator-dependent issues are transducer precompression, as well as the selection of the imaging plane through the nodule and of the ROI on the colour image. 15 Furthermore, the colour codes continue to vary even after three and up to ten seconds during the acquisition processa problem that is most pronounced in stiffer nodules.…”

Does Shear Wave Elastography Provide Additional Value in the Evaluation of Thyroid Nodules That Are Suspicious for Malignancy?

“…To overcome these limitations, we excluded nodules with cystic components of greater than 25% and calcifications with shadows that occupied greater than 25% on US, as well as nodules located in the isthmus because it is often too difficult to distinguish between actual stiffness and artifacts in this region. However, some studies assessed the influence of the cystic composition, calcification, and localization of lesions on the results of SWE examinations of patients with thyroid nodular disease 31 , 32 . Therefore, more in‐depth studies on parameters influencing SWE and the relationship between the elastic indices of lesions and their histopathologic findings are needed.…”

Risk stratification of thyroid nodules with Bethesda category III results on fine-needle aspiration cytology: The additional value of acoustic radiation force impulse elastography

“…Therefore, ARFI imaging may play more promising role in clinical practice. However, ARFI imaging also could be confounded by several factors, including inflammation and calcification, both of which are possible to increase estimated tissue stiffness [37, 38]. …”