ABSTRACT

The purpose of the current study was to investigate the prevalence of incidental paranasal sinus abnormalities on brain magnetic resonance imaging (MRI). We also aimed to assess the season, the age and sex-related differences in the frequencies of these abnormalities.

Paranasal sinus cavities of 839 patients who underwent brain MRI for suspected intracranial pathology were retrospectively evaluated for the presence of incidental abnormalities. Two study groups were established according to the season in which the MRI examinations were performed, and the prevalences of the incidental sinusal abnormalities in both winter and summer were calculated. The relation of the incidental sinusal abnormalities to age and sex were also analyzed.

Of the 839 patients, 45.5% showed one or more sinusal abnormalities. The prevalence of the sinusal abnormalities was significantly higher in winter (50.6%) than in summer (40.3%) (p=0.003). While sphenoidal sinus lesions did not show significant seasonality (p>0.05), frontal, maxillary and ethmoidal sinus lesions were significantly more common in winter than in summer (p<0.05). In both summer and winter, incidental sinusal abnormalities among men were significantly higher than among women (p values of 0.013 and 0.033, respectively). There was no significant relationship between incidental sinus abnormalities and age in either season (p>0.05).

Paranasal sinus abnormality is a frequent incidental brain MRI finding which is more commonly detected in winter. Awareness of incidental paranasal sinus abnormalities and knowledge of its frequency contribute positively to clinical applications.

Keywords: Magnetic resonance imaging, incidental findings, paranasal sinuses, sinusitis