High-resolution CT of the temporal bone in dysplasia of the auricle and external auditory canal.

TLDR

The study aimed to identify CT abnormalities in the external, middle, and inner ear of patients with microtia and external auditory canal dysplasia. High‑resolution CT with 1‑mm continuous sections, coronal/sagittal reformations, or low‑dose spiral scans was performed on 184 temporal bones of children with microtia. In minor microtia, auditory canal stenosis was most common, whereas major microtia was mainly associated with atresia; middle‑ear malformations correlated with auricular severity, and inner‑ear abnormalities—including ossicle dysplasia (98%), oval‑window absence (36%), labyrinthine malformations (13%), closed round window (6%), facial‑canal displacement (up to 75%), and vascular‑canal aberrations (38% in severe cases)—were frequently observed, indicating a spectrum of temporal‑bone changes linked to microtia.

Abstract

PURPOSE To determine CT findings in the external, middle, and inner ear of patients with microtia and external auditory canal dysplasia. METHODS We used high-resolution CT, with multiplanar or axial 1-mm continuous sections, coronal or sagittal reformations, or low-dose spiral acquisitions, to examine 184 temporal bones of children with microtia. RESULTS In cases of minor microtia, auditory canal stenosis was the most common associated abnormality; in those with major microtia, atresia was predominant. Middle ear malformations depended on the severity of the auricular anomalies. Inner ear changes could also be noted. Ossicle dysplasias occurred in 98% of patients (stapes, 72%), absence of the oval window in 36%, labyrinthine malformations in 13%, closed round window in 6%, facial canal displacement in up to 75%, and aberrations of the vascular canal in 38% of patients with third-grade auricular deformity. CONCLUSION A variety of external, middle, and, less frequently, inner ear changes were detected in connection with microtia.