[Chronic sinusitis in children. Current role of diagnostic imaging].

A retrospective study of a large series of patients (5,100 cases of radiologically confirmed rhino-sinusitis) was carried out to assess the efficacy of traditional radiology in the diagnosis of chronic sinusitis and the specific role of more recent imaging techniques. Traditional radiography, often limited to the naso-occipital projection (lack of collaboration), allows a reliable examination only of maxillary sinus. "Typical" findings of chronic sinusitis have been identified as "polipoid" thickening of the mucous membrane and localised parietal opacity. Both maxillary sinuses are involved in approximately 91% of cases, with ethmoidal involvement in 53%. Thickened mucosal walls and retention cysts may be obscured by inflammatory exudate: the air space is reduced and the sinus appears cloudy or opaque (acute reinflammation). The overall frequency of chronic sinusitis is 11.1% (67% in the 8-14 age range, 29% in the 5-8 age range and 4% in the 2-5 age range). Complications are rare (4 cases). Whereas echotomography provides limited and inconstant findings, CT and MRI are indicated in case of isolated opacity of a maxillary sinus, persistent after treatment: the former allows a detailed study of the bone, the latter enables to obtain a better tissue characterization. MRI often allows the differential diagnosis between inflammatory diseases and malignant tumors.