Acoustic reflectometry in discrimination of otoscopic diagnoses in young ambulatory children.

BACKGROUND: Studies concerning spectral gradient acoustic reflectometry (SG-AR) have analyzed middle ear effusion only as 1 entity. The usefulness of SG-AR to detect specific otoscopic diagnoses of otitis media in young children is unknown.

METHODS: Among 515 children aged 6-35 months, we compared SG-AR with pneumatic otoscopy and evaluated the proportions of 5 manufacturer-recommended SG-AR levels in relation to specific otoscopic diagnoses in 2802 and 1240 examinations at symptomatic and asymptomatic visits, respectively.

RESULTS: At symptomatic visits, when the angle value was >95° (level 1), healthy middle ear was diagnosed in 76% of otoscopic examinations and acute otitis media in 5%. Levels 2 (70-95°) and 3 (60-69°) did not relate to any otoscopic diagnosis. Levels 4 and 5 associated with acute otitis media in 50% and 64%, and otitis media with effusion in 33% and 32% of examinations, respectively. At asymptomatic visits, levels 1, 2 and 3 were associated with healthy middle ear in 87%, 71% and 54% of examinations, respectively. With levels 4 and 5, otitis media with effusion was diagnosed in 62% and 79% of examinations, respectively.

CONCLUSIONS: SG-AR is not useful in making specific otoscopic diagnoses. Although the extremities of 5 SG-AR levels are able to differentiate ears with and without effusion, SG-AR is not able to differentiate acute otitis media from otitis media with effusion. Therefore, SG-AR can aid in diagnostics, but careful pneumatic otoscopy is needed to determine accurate diagnoses.