Thyroglossal duct cyst imaging: Thyroid scintigraphy versus Ultrasound

The two imaging modalities most frequently used in thyroglossal duct cyst (TDC) are thyroid scintigraphy and ultrasound. The imaging is mainly used to exclude the cyst from being the only functioning ectopic thyroid tissue. The main objective of this study is to compare the results of scintigraphy and ultrasound.Methods: A total of 56 patients referred to the National Cancer Institute (NCI), University of Gezira in the period from Jan 2007 to Dec 2009 were included in this study, 30 females and 26 males patients; with median of 12.5 years. Data were analyzed by SPSS software.Results: Both thyroid scintigraphy and ultrasound reached the same imaging findings i.e. 53 patients with TDC and 3 patients with ectopic thyroid tissues. The Fisher exact test revealed no significant difference between the two modalities final results (P- value = 1). In addition, Pearson correlation showed complete correlation between the final ultrasound and scintigraphy results (R2 = 1, P-value < 0.0001). Furthermore, ultrasound has provided detailed cyst characterization.Conclusion: Both modalities revealed almost identical results. Ultrasound has the additional advantages of being non-ionizing radiation and accurately localizes and characterizes the TDC.Keywords: thyroid scan, thyroid ultrasound.