Maxillary sinus aspergillosis: Diagnosis and differentiation of the pathogenesis based on computed tomography densitometry of sinus concretions

Purpose: The efficacy of preoperative computed tomography (CT) densitometry in evaluating the origin of sinus concretions (SC) in sinus aspergillosis (SA) and its value for differentiation between a dental (endodontic) and an aerogenic pathogenesis were examined. Patients and Methods: Thirty-two patients who demonstrated radiodense maxillary sinus concretions in standard radiography underwent an additional preoperative CT examination of the maxillary sinus and the SC. The density of the SC and the root canal filling materials was assessed. The SC were subdivided into organic (< 1,500 HU) and inorganic (> 1,500 HU) masses; this classification was useful in the differentiation between a dental and an aerogenic pathogenesis of SA. Results: SA was diagnosed in 22 patients (68.8%). The SC of SA patients had a density of 2,566.5 ± 713.6 HU, whereas those of patients without SA had a density of 1,159.9 ± 1,008.4 HU ( P < .01). A correlation between the density of inorganic SC and that of root filling materials was found ( r = .78, P < .01). Conclusion: CT densitometry allows a classification of SC into two subgroups. The correlation between the density of root filling materials and that of radiodense sinus concretions seems to point to a “dental” origin of some concretions in SA. However, “organic” masses found in CT densitomentric examinations represent endogenous fungal products, which indicate an aerogenic pathogenesis of SA. Additional CT examinations of radiodense sinus concretions may thus be of some value for diagnosing SA and differentiating their pathogenesis.