7-year-old female Domestic Short-hair cat, with peripheral vestibular signs, left otitis media was suspected. An MRI of the head was performed.
The left external ear canal is well aerated with normal wall. The left tympanic bulla shows a mild diffuse thickening of its wall, without signs of lysis. In addition, it is completely occupied by material of mixed intensity on T2W, slightly hyperintense to the musculature on T1W and with marked enhancement of the inner surface of the wall (blue arrows).
The adjacent soft tissues, ventral to the bulla, show a very mild enhancement (pink arrow).
3D T1 FS+Gd
The structures of the left inner ear (cochlea and vestibule) are hyperintense on T2W, but there is no suppression of the intralabyrinthine fluid in FLAIR, showing a moderate and homogeneous contrast enhancement (green arrows).
There is an abnormal post-contrast enhancement of the facial (N.VII) and vestibulocochlear (N.VIII) nerves (yellow and orange arrows, respectively).
3D T1 FS
No alterations are detected in the right external ear canal, tympanic bulla or inner ear. The nasopharynx is well aerated.
The are no intracranial abnormalities.
The left medial retropharyngeal lymph node is slightly more prominent and asymmetric compared to the contralateral side (yellow arrows).
- Findings in the left ear, consistent with otitis media and interna, associated with inflammation of the adjacent soft tissues (ventral to the tympanic bulla) and left facial and vestibulocochlear neuritis.
- Ipsilateral medial retropharyngeal lymphadenopathy, most likely reactive.
The findings are consistent with an inflammatory/infectious process affecting the left middle and inner ear most likely, based on the imaging findings and history of the patient. Sampling of the material in the middle ear by myringotomy, performing cytology and culture, is required for a definitive diagnosis, if considered clinically appropriate.
The following article might be of interest:
Dutil GF, Guevar J, Schweizer D, et al. Otitis media and interna with or without polyps in cats: association between meningeal enhancement on postcontrast MRI, cerebrospinal fluid abnormalities, and clinician treatment choice and outcome. Journal of Feline Medicine and Surgery. 2022;24(12):e481-e489. doi:10.1177/1098612X221125573
Everest S., Monteith G., Gaitero L. et al. Suppression of inner ear signal intensity on fluid-attenuated inversion recovery magnetic resonance imaging in cats with vestibular disease. J Feline Med Surg. 2023 Apr;25(4):1098612X231168001. doi: 10.1177/1098612X231168001.