Imaging studies of pyriform sinus fistula

Background. Pyriform sinus fistula (PSF) refers to a persistent embryologic third or fourth pharyngeal pouch, which typically presents as a congenital sinus tract that originates from the pyriform sinus. The sinus tract is often diagnosed by a barium study or direct endoscopic inspection. Utilization of advanced imaging studies, including ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI), may aid in the diagnosis of this disease entity. Objectives: To review the imaging findings of PSF and demonstrate the value of various cross-sectional imaging (US, CT, and MRI) in the diagnosis of PSF. Materials and methods: PSF in five children was verified surgically. Preoperative barium esophagography, US, CT, and MRI were performed selectively in these patients. The clinical and imaging findings are reviewed retrospectively. Results: Barium studies demonstrated the sinus tract in all five patients. US, CT, and MRI demonstrated an associated inflammatory process. By utilizing the trumpet maneuver, the presence of sinus tract was evident in two patients during US. The sinus tract is also demonstrated by CT in another patient. Conclusions: Although barium esophagography is advantageous in demonstration of the sinus tract in PSF, US and CT are also capable of showing the sinus tract. The extent of inflammatory process related to PSF is better delineated by US, CT, and MRI.