Diagnostic value of MRI in dogs with inflammatory nasal disease.

OBJECTIVES To determine the value of low-field magnetic resonance imaging in differentiating sino-nasal aspergillosis from lymphoplasmacytic rhinitis in dogs. METHODS A retrospective study of 41 dogs (25 with lymphoplasmacytic rhinitis and 16 with sino-nasal aspergillosis) that underwent magnetic resonance imaging scan of the nasal cavity was conducted. On magnetic resonance imaging, turbinate destruction was classified as mild, moderate or severe. The cribriform plate and vomer destruction were classified as present or absent. The intensity of fluid accumulation and turbinates was classified on T1-weighted and T2-weighted images as hypointense, hyperintense and isointense based on the brightest area on the same slice. RESULTS Turbinate destruction was significantly (P=0·005) associated with sino-nasal aspergillosis. On T1-weighted images, sino-nasal aspergillosis was associated with turbinate hyperintensity, while lymphoplasmacytic rhinitis was significantly (P=0·007) associated with hypointensity. On T2-weighted images, this feature was shown not to be relevant. CLINICAL SIGNIFICANCE This study has demonstrated that turbinate destruction is the most reliable feature to differentiate sino-nasal aspergillosis from lymphoplasmacytic rhinitis and that T1-weighted image was the most useful sequence.