Some aspects of nasal disease in the cat

The aim of this study was to describe the radiographic signs of cats with chronic nasal disease and to assess the level of agreement between two independent observers in identifying these features. Nasal radiography of 85 cats were reviewed retrospectively by two independent observers. Computed Tomography and Magnetic Resonance Imaging were also performed in five and one cases respectively. Individual review was followed by consensual evaluation. The consensual radiological diagnosis was compared to the definitive diagnosis confirmed by histopathology. Seventy three cats were included in this part of the study, 55 (75%) cats had rhinitis and 18 (25%) had definitive diagnosis of neoplasia. The positive predictive values (PPV) were calculated for the diagnosis of each disease. The agreement between observers was also evaluated. The signs with higher PPV for nasal neoplasia were invasion of bony case (PPV=18.2%) and vomer destruction (PPV=86.6%). Generalized unilateral location of the lesion had a PPV of 46.7%, whereas both loss of turbinate detail and soft tissue opacity showed a PPV of 42.8%. When these signs occurred together in an animal with nasal neoplasia, the PPV reached 80%. Radiographic signs for rhinitis were more variable. The presence of a mixed pattern (PPV=84%), and nasal cavities within normal limits (PPV=18.2%) were the features frequently found. A high level of agreement between observers as to the final radiographic diagnosis (k=0.94). With regard to the specific features of nasal neoplasia and rhinitis, the agreement was very good in tumour cases; but in rhinitis was moderate, which confirms the variability of the rhinitis lesions. I summary, this study indicates a high degree of accuracy in the differentiation of radiographic features of neoplasia and chronic rhinitis in cats with chronic nasal disease.