Diagnostic Accuracy of Real-Time Sonography in Differentiating Diffuse Thyroid Disease From Normal Thyroid Parenchyma: A Multicenter Study.

ABSTRACT

OBJECTIVE: The purpose of this multicenter study was to assess the diagnostic accuracy of real-time sonography (US) for differentiating diffuse thyroid disease (DTD) from normal thyroid parenchyma among radiologists blinded to patients' clinical, serologic, and imaging history and to determine the differences in diagnostic accuracy among radiologists from different institutions. MATERIALS AND METHODS: From January to March 2017, 214 patients underwent preoperative thyroid US and subsequent thyroid surgery at four participating institutions. Real-time US was performed at each institution by an attending radiologist, who classified US diagnoses into one of the following four categories based on US findings: no DTD, indeterminate, suspicious for DTD, and DTD. The outcomes of US diagnoses were compared with histopathologic results to determine the diagnostic accuracy of real-time US at each institution. RESULTS: Histopathologic results included normal thyroid parenchyma (n = 143), Hashimoto thyroiditis (n = 29), non-Hashimoto lymphocytic thyroiditis (n = 37), and diffuse hyperplasia (n = 5). Normal thyroid parenchyma and DTD exhibited statistically significant differences in echogenicity, echotexture, size, glandular margin, vascularity of thyroid, and US classification. There was positive correlation between US classification and histopathologic results at all institutions for detecting DTD. The highest diagnostic indexes were obtained when the cutoff criterion was suspicious for DTD. There was favorable diagnostic accuracy, with statistically significant differences, at all institutions for the diagnosis of DTD. CONCLUSION: Real-time US can be helpful for differentiating DTD from normal thyroid parenchyma.