[Arrested pneumatization of the sphenoid sinus: imaging characteristics]

Objective: To explore and analyze the imaging features of arrested pneumatization of the sphenoid sinus, so as to provide reference for identifying sphenoid lesions. Methods: From May 2018 to September 2019, a retrospective analysis was conducted on 350 patients (183 males and 167 females, aged between 18 and 73 years) who had been completed the sinus CT examination in the outpatient department of Beijing Chaoyang Hospital Affiliated to Capital Medical University. Their imaging data were collected and the CT/MRI characteristics of the sphenoid body were observed. SPSS 26.0 software was used for statistical analysis. Results: The rate of arrested pneumatization of the sphenoid sinus was 2.0% (7/350), which occurred in the pteroid process, the slope region, and the sphenoid sinus body, respectively. CT showed a nondilated mixed-density lesion (7/7) in the pneumatizable sphenoid body. Within these regions, both fat and soft tissue density (7/7) were present. Internal curve calcification was observed in part of the region (3/7). The skull base canal structure was not affected (7/7). MRI showed a clear non-dilated lesion with an adipose signal, and none of the lesions showed medulla dilation or cortical destruction. Conclusions: Arrested pneumatization of the sphenoid sinus is a normal anatomic variation. When non-dilated lesions with clear bony boundaries and internal fatty components are encountered in the vaporizable region of the sphenoid sinus, the possibility of arrested pneumatization of the sphenoid sinus should be considered.