title: Magnetic resonance imaging of a brain abscess in a 10-month-old filly.
abstract: The purpose of this paper was to correlate the magnetic resonance imaging (MRI) characteristics of a mature brain abscess in a horse with histopathologic alterations of brain tissue. Eight months after the onset of clinical signs, MRI of the brain of a 10-month-old filly was performed. A large space-occupying lesion in the right cerebral hemisphere was identified. This space-occupying lesion was delineated by a thick and well-defined capsule that was isointense to brain parenchyma on the T1-weighted images and with a markedly hypointense on the T2-weighted images. The identification of such a capsule is highly diagnostic of a mature brain abscess. The lesion seen on MR images was confirmed at necropsy where a large abscess of the right hemisphere was observed. Streptococcus zooepidemicus and Pseudomonas aeruginosa were isolated from the abscess. Based on histopathologic examination, the signal characteristics of the capsule on T1-weighted and T2-weighted images were found to be due to the presence of numerous hemosiderin-laden macrophages. These results are in agreement with previous studies on human patients. This report confirms the value of MRI in the diagnosis of equine brain diseases.
authors.affiliation: CIRALE-IPC, UMR Biomécanique et Pathologie Locomotrice du Cheval, Ecole Nationale Vétérinaire d'Alfort, RN 175, 14430 Goustranville, France.
authors.forename: F
authors.initials: F
authors.lastname: Audigié
authors.forename: J
authors.initials: J
authors.lastname: Tapprest
authors.forename: C
authors.initials: C
authors.lastname: George
authors.forename: D
authors.initials: D
authors.lastname: Didierlaurent
authors.forename: N
authors.initials: N
authors.lastname: Foucher
authors.forename: F
authors.initials: F
authors.lastname: Faurie
authors.forename: M
authors.initials: M
authors.lastname: Houssin
authors.forename: J M
authors.initials: JM
authors.lastname: Denoix
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001922:Brain Abscess / Q000175:diagnosis / Q000662:veterinary*; D003937:Diagnosis, Differential; D005260:Female; D006734:Horse Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D006736:Horses; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D011552:Pseudomonas Infections / Q000175:diagnosis / Q000662:veterinary*; D011550:Pseudomonas aeruginosa / Q000302:isolation & purification; D011859:Radiography; D013290:Streptococcal Infections / Q000175:diagnosis / Q000662:veterinary*; D018502:Streptococcus equi / Q000302:isolation & purification