The Emerging Echogenic Tract Sign of Pyriform Sinus Fistula: An Early Indicator in the Recovery Stage of Acute Suppurative Thyroiditis

Abstract

AST is commonly associated with pyriform sinus-thyroid fistula in children. Radiologic findings of AST are documented in a few reports. We report a new sign we term the "emerging echogenic tract sign," which reflects a patent air-containing pyriform sinus-thyroid fistula on follow-up US. Recognition of this sign is an important finding suggesting an associated pyriform sinus-thyroid fistula in a patient with AST and also suggesting the adequate timing of barium esophagography to confirm the fistula.