Quantitative assessment of thyroid-to-background ratio improves the interobserver reliability of technetium-99m sestamibi thyroid scintigraphy for investigation of amiodarone-induced thyrotoxicosis

摘要

Background Amiodarone-induced thyrotoxicosis (AIT) is caused by excessive hormone synthesis and release (AIT I), a destructive thyroiditis (AIT II), or a combination of both (AIT Ind). Although no gold-standard diagnostic test is available, technetium-99m sestamibi thyroid scintigraphy (Tc-99m-STS) has been previously reported to be an accurate tool for differentiating subtypes with important therapeutic implications. However, the information to guide reporting of Tc-99m-STS is qualitative and highly subjective. This study aims to compare the interobserver reliability of Tc-99m-STS before and after the use of quantitative thyroid-to-background ratios (TBRs) displayed on a time-activity curve for differentiation of AIT subtypes.