CT features of congenital nasal piriform aperture stenosis: initial experience

To describe the computed tomographic (CT) measurements and features that enable accurate diagnosis of congenital nasal piriform aperture stenosis (CNPAS).

The clinical and imaging features of six patients (age range, 0-11 months) with CNPAS were retrospectively evaluated and compared with those of 61 control subjects younger than 24 months.

The average widths of the piriform aperture in patients aged 0-3, 4-6, and 10-12 months were 4.8, 7.0, and 6.0 mm, respectively, compared with 13.4 (P < .001), 14.9, and 15.6 mm, respectively, in the age-matched control subjects. The average areas of the piriform aperture in patients in the three age groups measured 0.24, 0.46, and 0.36 cm2, respectively, compared with 0.67 (P < .001), 0.86, and 1.11 cm2, respectively, in the age-matched control subjects. The width of the nasal cavity in patients with CNPAS was in the less than 5th percentile compard with that in the control subjects. Abnormal dentition and a midline bone ridge projecting from the inferior palate were present in all six patients.

CT measurement of the piriform aperture width is a simple and accurate method for diagnosing CNPAS; a width less than 11 mm in a term infant is considered to be diagnostic. An abnormal dentition and a bone ridge along the underside of the palate are confirmatory imaging findings.