Magnetic resonance imaging of a brain abscess in a 10-month-old filly.

This study used magnetic resonance imaging (MRI) to successfully identify and analyse a mature brain abscess in a young horse. Following clinical signs of illness, the MRI process confirmed the presence of a large abnormality in the brain that correlated with further histopathological findings.

Study Purpose and Methodology

• The main goal of this research study was to analyze the MRI features of a mature brain abscess in a horse and compare it with the histopathologic alterations observed in the brain tissue.
• A 10-month-old filly, who had exhibited clinical signs for eight months, underwent an MRI scan. This imaging technique enabled the researchers to identify a large mass in the right cerebral hemisphere of the horse’s brain.

Detection and Identification of Lesion

• The mass was characterized by a thick and well-defined capsule that appeared isointense (same intensity) to the regular brain parenchyma tissue on T1-weighted images.
• On T2-weighted images, the capsule showed markedly hypointense (appearing darker) than the surrounding brain tissue. This type of appearance is a key diagnostic feature of a mature brain abscess.
• The diagnosis, made from the MRI images, was confirmed through a necropsy, which revealed a large abscess in the same hemisphere that the MRI had highlighted.

Microbiological and Histopathological Findings

• Two types of bacteria were found in the abscess: Streptococcus zooepidemicus and Pseudomonas aeruginosa. These bacteria are commonly associated with infections in animals.
• A histopathological examination was conducted on the brain tissue. This examination explained the MRI image findings, revealing that the signal characteristics were caused by a large number of hemosiderin-laden macrophages, a type of immune cell that has engulfed waste products.
• This result was consistent with outcomes from previous studies conducted on human patients.

Study Conclusion

• The study importantly confirms the value of MRI use to identify and diagnose brain diseases in equine patients. It shows that MRI images combined with histopathological examinations can provide a comprehensive understanding of brain abscess’s structure and composition.