Radiographic, magnetic resonance imaging, computed tomographic, and rhinoscopic features of nasal aspergillosis in dogs

OBJECTIVE: To determine radiographic, magnetic resonance imaging (MRI), computed tomography (CT), and rhinoscopic features of nasal aspergillosis in dogs. DESIGN: Prospective study. ANIMALS: 15 client-owned dogs. PROCEDURE: All dogs had clinical signs of chronic nasal disease; the diagnosis of nasal aspergillosis was made on the basis of positive results for at least 2 diagnostic tests (serology, cytology, histology, or fungal culture) and detection of typical intrasinusal and intranasal fungal colonies and turbinate destruction via rhinoscopy. Radiography, MRI, and CT were performed under general anesthesia. Rhinoscopy was repeated to evaluate lesions and initiate treatment. Findings of radiography, MRI, CT, and rhinoscopy were compared. RESULTS: MRI and CT revealed lesions suggestive of nasal aspergillosis more frequently than did radiography. Computed tomography was the best technique for detection of cortical bone lesions; the nature of abnormal soft tissue, however, could not be identified. Magnetic resonance imaging allowed evaluation of lesions of the frontal bone and was especially useful for differentiating between a thickened mucosa and secretions or fungal colonies; however, fungal colonies could not be differentiated from secretions. Rhinoscopy allowed identification of the nature of intranasal and intrasinusal soft tissue but was not as useful as CT and MRI for defining the extent of lesions and provided no information regarding bone lesions. CONCLUSIONS AND CLINICAL RELEVANCE: The value of CT and MRI for diagnosis of nasal aspergillosis was similar and greater than that of radiography. Rhinoscopy is necessary because it is the only technique that allows direct visualization of fungal colonies.