MAGNETIC RESONANCE IMAGING AND COMPUTED-TOMOGRAPHY CHARACTERISTICS OFINTRACRANIAL INTRA-ARACHNOID CYSTS IN 6 DOGS

Magnetic resonance imaging (MRI) and computed tomographic imaging (CT) characteristics of intracranial intra-arachnoid cysts in six dogs are described, Of the six dogs, three were less than one year of age and 4 were males, Five of the six dogs weighed less than 11 kg, Five cysts were located in the quadrigeminal cistern, On CT images, the intracra nial intra-arachnoid cysts had sharply defined margins, contained flui d isodense to CSF and did not enhance following IV administration of c ontrast, On MRI images, the intracranial intra-arachnoid cysts were ex tra-axial, contained fluid isointense with CSF and did not enhance fol lowing IV contrast, While spinal arachnoid cysts of dogs have been rep orted in the literature, other than the six dogs contained in this rep ort, intracranial intra-arachnoid cysts have not to our knowledge been described in animals, These six dogs have a similar age, sex, history , clinical signs, CT and MRI findings to those reported in people with intracranial intra-arachnoid cysts.