Diagnostic Accuracy of Ultrasound in Diffuse Form of Hashimotoâ??s Thyroiditis

Abstract

Adithya Das1 , Danny Jose Titus2

BACKGROUND Hashimoto’s thyroiditis is a common thyroid disorder of autoimmune aetiology with circulating antithyroid antibodies. It has a high prevalence of 12 % among the female population and has varied clinical and serological presentation. We wanted to describe the sonological findings in diffuse form of Hashimoto’s thyroiditis and assess the diagnostic accuracy of different sonological parameters in the detection of Hashimoto’s thyroiditis. METHODS Ultrasound features associated with Hashimoto’s thyroiditis namely gland enlargement, echogenicity, presence of micronodules, echogenic septations, illdefined macroscopic areas, surface micro-lobulations, vascularity, and level VI cervical lymph nodes were evaluated in 60 patients with diagnosed Hashimoto’s thyroiditis and were compared with 60 control subjects. Sensitivity, specificity, positive predictive value and negative predictive values were calculated for separate sonological features. RESULTS Altered echotexture of the gland was seen in all patients with Hashimoto’s thyroiditis. Echogenic septations showed most sensitivity (83.3 %) in detecting Hashimoto’s thyroiditis. Presence of micro nodules was found to have high specificity (98.3 %), but decreased sensitivity. Surface microlobulations had a positive predictive value and specificity of 100 % in the diagnosis of Hashimoto’s thyroiditis. Macroscopic ill-defined areas were found to have intermediate accuracy values. Increase in the gland vascularity on Doppler and presence of benign cervical lymph nodes in level VI region were found to have high sensitivity and specificity values. CONCLUSIONS Echogenic septation was the most sensitive parameter in diagnosing Hashimoto’s thyroiditis, a finding which represented the ongoing fibrosis within the gland. Sonological findings of micronodules and surface micro-lobulations were found to be specific to Hashimoto’s thyroiditis. Along with the assessment of gland vascularity and level VI cervical lymph nodes, ultrasound has high specificity and sensitivity in the diagnosis of Hashimoto’s thyroiditis.

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