Correlation between the size of incidental thyroid nodules detected on CT, MRI or PET-CT and subsequent ultrasound

Purpose: The aim of this study was to assess the relationship between size of thyroid nodules at computed tomography (CT), magnetic resonance imaging (MRI) or positron emission tomography Cr (PET-CT), and size at ultrasound. Materials and methods: We performed a retrospective review of thyroid ultrasound studies over a 2-year period. Results: A total of 307 patients were included in the study. There was a statistically significant difference between the size of nodules measured on ultrasound compared with cross-sectional imaging (P <.001). American College of Radiology white paper recommendations would have decreased ultrasound referrals by 24% without any additional missed malignancies. Conclusion: Cross-sectional imaging underestimates the size of thyroid nodules; however, the difference is small and likely not clinically significant. (C) 2016 Elsevier Inc. All rights reserved.