Magnetic resonance findings in a domestic short‐hair cat with presumptive mucopolysaccharidosis

Prevalence and clinical correlations of olfactory recess dilatation in MRI studies of the feline brain

The ability to differentiate clinical ventriculomegaly from incidental ventricular enlargement remains a challenge in veterinary radiology. Dilatation of one or both olfactory lobe recesses is occasionally seen on MRI of the brain in otherwise normal cats. The purpose of this study was therefore to determine the prevalence of this finding within a population of neurologically normal and neurologically abnormal cats, and to investigate associations with signalment, clinical and neurological examination findings, and MRI features. An observational retrospective cohort study was performed, and archived records were searched for cats that had undergone MRI of the head, including the olfactory lobes. Medical data and MRI parameters were recorded. One hundred fifty-one cats were included, with olfactory recess dilatation present in 56 cats. In 16 neurologically normal cats, olfactory recess dilatation was the only MRI finding. Olfactory recess dilatation was not associated with age, sex, breed, or with the presence of nasal disease. A significant association was found between generalized ventriculomegaly (P = 0.001) and the presence of CSF abnormalities (P = 0.036). Eleven percent of our cohort (16/151) demonstrated olfactory recess dilatation in the absence of other neurological or structural intracranial disease, suggesting that this may be seen as a normal variation in some cats.

CT and MRI characteristics of presumptive hypervitaminosis A in a cat

Case summary

A rescued stray cat with an unknown history was examined for non-ambulatory paraparesis in the hindlimbs. Survey radiographs revealed typical findings of hypervitaminosis A, characterised by vertebral exostoses and extensive osteophytes, mainly in the cervicothoracic spine. CT findings were consistent with the radiographic findings, and CT-based volume rendering and virtual endoscopy into the vertebral canal were created for three-dimensional visualisation of the lesion. MRI revealed a focal and mild dilation of the central canal of the spinal cord. Although the clinical diagnosis of hypervitaminosis A is based on an unusual dietary history and characteristic radiographic findings, the history of this cat was unknown and serum concentrations of vitamin A were unremarkable, when measured >1 month after rescue. However, other possible differential diagnoses were thought to be unlikely and clinical signs never worsened, and thus, hypervitaminosis A was presumed.

Relevance and novel information

To our knowledge, this is the first report to present the CT and MRI characteristics of a cat with suspected hypervitaminosis A.