Computer‐Assisted Magnetic Resonance Imaging Brain Morphometry in American Staffordshire Terriers with Cerebellar Cortical Degeneration

Abstract

Cerebellar cortical degeneration exists in American Staffordshire Terriers. Magnetic resonance imaging (MRI) can be suggestive, but a definitive diagnosis requires histopathology. Computer-assisted MRI morphometry can be used to distinguish between American Staffordshire Terriers with or without cerebellar cortical degeneration. Normal American Staffordshire Terriers (n = 17) and those with clinical signs of cerebellar cortical degeneration (n = 14). 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). 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. 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.