Computer-assisted magnetic resonance imaging brain morphometry in American Staffordshire Terriers with cerebellar cortical degeneration

BACKGROUND: Cerebellar cortical degeneration exists in American Staffordshire Terriers. Magnetic resonance imaging (MRI) can be suggestive, but a definitive diagnosis requires histopathology. HYPOTHESIS: Computer-assisted MRI morphometry can be used to distinguish between American Staffordshire Terriers with or without cerebellar cortical degeneration. ANIMALS: Normal American Staffordshire Terriers (n = 17) and those with clinical signs of cerebellar cortical degeneration (n = 14). METHODS: This was a partly retrospective and partly prospective study. Causes of cerebellar disease were ruled out with brain MRI, cerebrospinal fluid (CSF) analysis, CBC, blood biochemistry, and clinical follow-up. On T2-weighted midsagittal MR images, the following parameters were calculated: size of the cerebellum relative to the entire brain, size of the CSF space surrounding the cerebellum relative to the cerebellum, and 2 threshold-dependent cerebellar CSF indices (with and without surrounding CSF). RESULTS: Statistical analyses indicated a significantly lower relative cerebellar size (P < .001) and a larger relative cerebellar CSF space (P < .001) in dogs with cerebellar cortical degeneration. The measurement of relative cerebellar size could distinguish between affected and nonaffected dogs with a sensitivity and a specificity of 93 and 94%, respectively, using a cut-off of 13.3%. Using a cut-off of 12.8%, the measurement of relative CSF space could distinguish between both groups with a sensitivity of 93% and a specificity of 100%. There was a significant difference in 1 of the 2 CSF indices between affected and normal dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Relative cerebellar size and relative CSF space calculated from MRI are effective in American Staffordshire Terriers to differentiate between normal animals and those with cerebellar cortical degeneration.