Evsen Polattas Solak MD, Presenter: Nothing to Disclose

Suna Ozhan Oktar MD, Abstract Co-Author: Nothing to Disclose

Emetullah Cindil MD, Abstract Co-Author: Nothing to Disclose

Doga Ozdemir MD, Abstract Co-Author: Nothing to Disclose

Cem Yucel MD, Abstract Co-Author: Nothing to Disclose

The aim of this study was to evaluate diagnostic performance of US elastography in differentiating benign and malignant thyroid nodules in the background of chronic thyroiditis and to compare it with grey scale US and Doppler findings.

Patients with chronic thyroiditis who had a coexisting nodule that was proven by fine needle aspiration or surgical pathologic analysis to be benign or malignant were included in the study. The US elastographic image was matched with an elasticity color scale and nodules were classlfied into 4 groups using elasticity score. In addition, parenchyma to tumor strain ratio (strain index) was calculated. Grey scale properties ( internal structure, echogenity, presence or absence of hypoechoic halo sign, microcalcifications, ‘taller than wide’ sign ), vascularity scores, elasticity scores and mean strain ratios of all nodules were compared with their pathologic diagnosis.          

Sixty seven of all nodules were benign and seven were malignant. Five of all malignant nodules were papillary carcinoma, one of them was lymphoma and one of them was thyroid carcinoma including different differentiation areas ( papillary carcinoma+epidermiod carcinoma+sarcomatous component ). Hypoechogenicity, absence of halo sign, microcalcifications, ‘taller than wide’ sign and irregular course of vascular structures were statistically related with malignancy. There was a statistically significant relation between high elasticity score and malignancy. We determined 6.16 as the cut-off point of the strain ratio. There was a statistically significant difference between the nodules with the strain ratio above and below 6.16. Solid internal structure, hypoechogenity, absence of hypoechoic halo sign and irregular course of vascular structures in nodule had the highest sensitiviy (100%); the strain ratio above 6.16 had the highest specificity (100%) among all nodule characteristics. 

Strain ratio values of malignant nodules with chronic thyroiditis is higher than the values of malignant nodules developing at the background of normal thyroid parenchyma. US elasotography is an asisting imaging technique to differentiate benign and malignant nodules associated with chronic thyroiditis.  

US elastography can be used to differentiate malignant nodules from benign nodules associated with chronic thyroiditis,especially in focal thyroiditis which can mimic carsinoma in gray scale features.

Polattas Solak, E, Oktar, S, Cindil, E, Ozdemir, D, Yucel, C, The Role of US Elastography in the Differential Diagnosis of Nodules Associated with Chronic Thyroiditis.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13044297.html