STIR muscle hyperintensity in the cervical muscles associated with inflammatory spinal cord disease of unknown origin.

Objectives: To assess the relation of a distinctive pattern of short tau inversion recovery muscle hyperintensity with inflammatory cerebrospinal fluid result in dogs.

Methods: All dogs that had a short tau inversion recovery sequence performed in addition to other magnetic resonance sequences of the cervical spine and concurrent cerebrospinal fluid evaluation during the study period were included. All magnetic resonance studies were anonymised and reviewed by a board certified radiologist and board certified neurologist. A board certified pathologist examined the cerebrospinal fluid and the results were reviewed.

Results: Forty-nine cases fulfilled the inclusion criteria. Repeatable patterns of short tau inversion recovery hyperintensity were identified in 20 dogs. The clinical diagnosis in all these 20 cases was of meningoencephalomyelitis of unknown origin. This diagnosis was confirmed by inflammatory cerebrospinal fluid changes in 18 and suspected from clinical presentation and response to therapy in the remaining 2.

Clinical Significance: In this study, the short tau inversion recovery changes identified were restricted to cases with inflammatory spinal cord disease. The short tau inversion recovery change had a sensitivity of 78%, and a specificity of 92% in predicting inflammatory cerebrospinal fluid, suggesting that short tau inversion recovery sequences are a useful addition to the investigation of suspected inflammatory spinal cord disease.