Material in the middle ear of dogs having magnetic resonance imaging for investigation of neurologic signs

Abstract

The aim of this study was to determine the prevalence and potential significance of finding material in the middle ear of dogs having magnetic resonance (MR) imaging. Of 466 MR studies reviewed, an increased signal was identified in the tympanic bulla in 32 (7%) dogs. Cavalier King Charles spaniels, Cocker spaniels, Bulldogs, and Boxers were over-represented compared to the population of dogs having MR imaging. Five (16%) dogs had definite otitis media and one (3%) had a meningioma invading the middle ear. Of the remaining dogs, 13 (41%) had possible otitis media and 13 (41%) had neurologic conditions apparently unrelated to otitis media. The most common appearance of material in the middle ear was isointense in T1-weighted images and hyperintense in T2-weighted images. There was no apparent correlation between the signal characteristics of the material and the diagnosis. Enhanced signal after gadolinium administration was observed affecting the lining of the bulla in dogs with otitis media and in dogs with unrelated neurologic conditions. In dogs without clinical signs of otitis media, finding an increased signal in the middle ear during MR imaging may reflect subclinical otitis media or fluid accumulation unrelated to inflammation. Brachycephalic dogs may be predisposed to this condition.

Prevalence of Ear Disease in Dogs Undergoing Multidetector Thin‐slice Computed Tomography of the Head

“…2,4 A previous study using MRI reported a prevalence of 7% for middle ear effusion in dogs that presented for neurologic signs. 5 In cats, a prevalence of 34% for subclinical middle ear disease has been reported. 6 A common cause of otitis media in dogs is as an extension of chronic otitis externa.…”

Prevalence and Characterization of Small Tympanic Bone Spicules and Drumstick‐like Hyperostotic Tympanic Bone Spicules in the Middle Ear Cavity of Dogs

“…2 Radiography, computed tomography (CT), and magnetic resonance imaging (MRI) represent valuable instruments to diagnose common middle ear diseases such as otitis media, (inflammatory) polyps, cholesteatomas, and neoplasms. [3][4][5][6] Diagnostic imaging findings commonly associated with middle ear disease include changes in the contour of the tympanic bulla, bone proliferation and/or osteolysis, or the presence of abnormal material in the middle ear cavity. 3,4 Occasionally, imaging findings of questionable clinical significance, formerly known as "otolithiasis," are observed on radiographs or CT scans of the tympanic cavities of dogs with variable signs of otitis media.…”

“…[3][4][5][6] Diagnostic imaging findings commonly associated with middle ear disease include changes in the contour of the tympanic bulla, bone proliferation and/or osteolysis, or the presence of abnormal material in the middle ear cavity. 3,4 Occasionally, imaging findings of questionable clinical significance, formerly known as "otolithiasis," are observed on radiographs or CT scans of the tympanic cavities of dogs with variable signs of otitis media. 7,8 "Otolithiasis" refers to the presence of rounded, smooth, sessile, hyperattenuating structures resembling mineral concretions with diameters of up to several millimeters on bulla CT scans of dogs.…”

Relationship between pharyngeal conformation and otitis media with effusion in Cavalier King Charles spaniels

“…Whereas otitis media/interna is usually associated with clinical signs (Little and others 1991), in CKCS this finding is almost invariably incidental during MRI scanning for neurologic diseases (Lu and others 2003, Owen and others 2004). The condition has previously been termed ‘primary secretory otitis media’ (PSOM) and has been associated with various neurologic signs and pain (Stern-Bertholtz and others 2003).…”