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Subject: search.filters.subject.magnetic resonance imaging

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    Relationship between admission vitals and brain herniation in 32 cats: a retrospective study
    (SAGE Publications on behalf of the International Cat Care Veterinary Society and Feline Veterinary Medical Association, 2022-08-01) Her J; Merbl Y; Gerken K; Kim M; Hofmeister E; Bacek LM; Kuo KW; Yanke AB
    Objectives: The aim of the study was to evaluate whether any admission vitals correlated with the presence of brain herniation diagnosed via MRI in cats presenting with neurologic signs. Methods: Medical records at two veterinary university referral centers were reviewed to identify cats that underwent brain MRI between 2010 and 2019. A control group of cats with intracranial lesions without concurrent brain herniation was analyzed for comparison. Data relating to signalment, vitals on admission, abnormalities observed on initial neurologic examination, underlying etiology, advanced imaging findings and outcome were reviewed. A Modified Glasgow Coma Scale (MGCS) score was determined retrospectively based on initial neurologic examination. Logistic regressions were performed to investigate the relationship between each risk factor and the odds of brain herniation as diagnosed on MRI. Results: Thirty-two cats with brain herniation and 44 cats with abnormal brain MRI without evidence of herniation (as a control group) based on MRI findings were included. Cats with intracranial neoplasia vs other diagnoses were found to be at increased risk of herniation (odds ratio [OR] 4.8, 95% confidence interval [CI] 1.8–13.8; P = 0.001). The odds of herniation increased with age (OR 1.1, 95% CI 1.01–1.2; P = 0.031). Cats with herniation had a significantly lower level of consciousness in their MGCS score (P <0.0001) than cats without herniation. There was no significant difference in either motor activity or brainstem reflexes between the groups (P >0.05). Conclusions and relevance: Admission heart rate and blood pressure were not associated with brain herniation. Cats with herniation were presented with a significantly lower level of consciousness in their MGCS score; however, this clinical feature cannot be directly attributable to and predictive of herniation. Older cats with intracranial neoplasia are more likely to have brain herniation.
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    Pathophysiology of Penetrating Captive Bolt Stunning in Horned and Polled Sheep and Factors Determining Incomplete Concussion.
    (MDPI (Basel, Switzerland), 2025-01-13) Gibson TJ; Ridler AL; Limon G; Lamb C; Williams A; Gregory NG; Bø-Granquist EG
    Penetrating captive bolt (PCB) is widely used for stunning and on-farm dispatch of livestock, yet its efficacy can vary, with the potential for animal welfare compromise. This study investigated the pathophysiology of PCB-induced trauma in horned and polled sheep (Ovis aries), focusing on factors contributing to incomplete concussion. Thirty-seven (n = 18 horned Scottish blackface and n = 19 polled North Country mule) mature ewes (aged 4-10 years) were shot with PCB with varying cartridge power and PCB modifications, followed by clinical assessment and post-mortem analysis using magnetic resonance imagining (MRI) and gross pathology. The results indicated that damage to the reticular activating system, bolt velocity and penetration depth are crucial for inducing irreversible unconsciousness, with depths less than 37 mm often resulting in incomplete concussion. MRI provided detailed insights into brain injuries, aligning well with gross pathological findings. This study highlights the importance of precise bolt placement and appropriate PCB configurations in ensuring humane outcomes, with MRI proving to be a valuable tool for assessing brain trauma in stunned animals. These findings enhance the understanding of effective stunning techniques and support improved welfare practices in livestock management.