title: Imaging studies of pyriform sinus fistula.
abstract: 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.
  
  
  OBJECTIVE
  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.
  
  
  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.
authors.affiliation: Department of Radiology, Taipei Veterans General Hospital, 201, Section 2, Shih-Pai Rd, Taipei, Taiwan 11217, Republic of China.
authors.forename: Hsin-Kai
authors.initials: HK
authors.lastname: Wang
authors.forename: Chui-Mei
authors.initials: CM
authors.lastname: Tiu
authors.forename: Yi-Hong
authors.initials: YH
authors.lastname: Chou
authors.forename: Cheng-Yen
authors.initials: CY
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D001934:Branchial Region / Q000002:abnormalities* / Q000196:embryology; D002648:Child; D005260:Female; D005402:Fistula / Q000175:diagnosis / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D016156:Respiratory Tract Fistula / Q000175:diagnosis* / Q000000981:diagnostic imaging; D013961:Thyroid Gland / Q000000981:diagnostic imaging; D013969:Thyroiditis, Suppurative / Q000175:diagnosis* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography