Comparison of imaging modalities in pediatric thyroglossal duct cysts.

OBJECTIVES/HYPOTHESIS: To determine and compare the accuracy of different imaging modalities including ultrasound (US), magnetic resonance imaging (MRI), and computed tomography (CT) in the diagnosis of thyroglossal duct cysts (TGDC) in children.

STUDY DESIGN: Retrospective chart review.

METHODS: A retrospective chart review was performed on patients under the age of 18 years who had undergone surgical excision of midline neck masses between January 2002 and June 2011. All patients had preoperative imaging. Data including age at surgery, preoperative imaging results, and postoperative pathology results were recorded. Preoperative imaging diagnoses were then compared to postoperative pathologic diagnoses. Diagnostic test statistics were performed.

RESULTS: A total of 44 patients met the study criteria. There were 15 patients who underwent more than one modality of imaging study. US had a sensitivity of 75% in diagnosis of TGDC. MRI sensitivity was 60% and CT was 82%. None of the tests had high specificity for TGDC; US was the highest at 80%. All three modalities had positive predictive values higher than 90%. US had the highest positive likelihood ratio (3.8), although the 95% confidence interval was not statistically significant.

CONCLUSIONS: In a comparison of the three most commonly used imaging modalities for pediatric TGDC, US was the preferred exam given its comparable accuracy, ease of administration, and lower cost. In addition, the added risks of general anesthesia with MRI and ionizing radiation with CT are not justified in this setting given their equivalent or inferior performance when compared to US in this cohort.