Intrasinus calcification is a phenomenon whereby calcification is formed within the paranasal sinuses. It can occur to varying extents, therefore leading to varying degrees of attenuation on CT. Such calcification may occur either concurrently within an opacified sinus or in an aerated sinus, depending on the state of infection/inflammation. Intrasinus calcification usually occurs in the setting of chronic sinusitis and can favor a fungal (especially Aspergillus) sinus infection 1.
Features favoring a fungal etiology include 1,2:
- location of intrasinus calcification: central in most patients with fungal sinusitis and peripheral in those with non-fungal sinusitis
- fine punctate type calcifications: often only seen in those with fungal sinusitis
- round or eggshell type calcifications: often only seen in those with non-fungal sinusitis
- calcifications with a nodular or linear shape can be seen in both fungal and non-fungal sinusitis
- 1. Yoon JH, Na DG, Byun HS et-al. Calcification in chronic maxillary sinusitis: comparison of CT findings with histopathologic results. AJNR Am J Neuroradiol. 1999;20 (4): 571-4. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 2. Momeni AK, Roberts CC, Chew FS. Imaging of chronic and exotic sinonasal disease: review. AJR Am J Roentgenol. 2007;189 (6_supplement): S35-45. doi:10.2214/AJR.07.7031 - Pubmed citation