MRI in Children With Pyriform Sinus Fistula

A variety of imaging modalities have been described for the diagnosis of congenital pyriform sinus fistula (CPSF). To date, there have been few MRI reports.

To evaluate MRI findings of CPSF and interobserver reliability.

Retrospective.

In all, 115 patients aged 23 days to 15.4 years at operation.

3.0T/axial T₁ -weighted image (T₁ WI)-SPIR, axial T₂ WI, axial T₂ WI-STIR, coronal T₂ WI-SPIR, diffusion-weighted imaging (DWI), axial and coronal gadolinium-enhanced T₁ WI-SPIR.

For each patient, the medical records, including demographics, clinical manifestations, and MRI findings were reviewed. All the MRI studies were interpreted by three radiologists independently.

Kendall's W test was made to determine the interobserver reliability of three reviewers for MRI findings.

CPSF occurred on the left side in 104 (90.4%) patients and on the right side in 11 (9.6%) patients. The male-to-female ratio was 59:56. The age at first episode varied from birth to 12.3 years. There was one neonate patient, who presented with a unilocular cystic mass in the left neck. A tunnel-like lesion between the pyriform fossa and the upper pole of the thyroid gland, T₂ high signal behind the cricothyroid joint, thyroid gland involvement, deep neck abscesses or masses were noted in 46 (40%), 93 (80.9%), 96 (83.5%), and 36 (31.3%) patients, respectively. There was excellent interobserver reliability for all the MRI findings, ranging from 0.84 to 1.00.

The sinus tract presenting with a tunnel-like lesion goes behind the cricothyroid joint in most cases. For patients presenting with acute suppurative thyroiditis (AST) or neck infection with thyroid gland involvement, the presence of T₂ high signal behind the cricothyroid joint highly suggests the diagnosis of CPSF. MRI is a reliable method for the diagnosis of CPSF.

4 TECHNICAL EFFICACY STAGE: 2.