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[Anatomic variations of the paranasal sinuses detected by computed tomography and the relationship between variations
Raşit Midilli1, Gürkan Aladağ, Ergin Erginöz
1Department of Otolaryngology, Medicine Faculty of Ege University, Izmir, Turkey. rmidilli@yahoo.com
Objectives:
In this study, we evaluated anatomic variations detected by computed tomography (CT) of the paranasal sinuses and their relationship with sex.
Patients And Methods:
Computed tomography scans of the paranasal sinuses of 464 patients (206 males, 258 females; mean age 37.5 years; range 4-87 years) were retrospectively analyzed. In cases requiring further investigation, axial and sagittal views were obtained using multiplanar reformatted images. Bone window images were also obtained particularly to evaluate dehiscence variations. Paranasal sinus variations were classified into eight subgroups according to their origins (nasal septum, ethmoid cells, maxillary sinus, uncinate process, frontal and sphenoid sinuses, orbit, and nasal concha). The frequency of variations was compared between male and females.
Results:
The most common anatomic variation was agger nasi cells (80.4%) followed by pneumatization of the middle concha (37%). The least encountered variations were pneumatization of the inferior turbinate, bony dehiscence of the ethmoidal roof, and duplication of the middle and superior turbinates. The frequency of variations did not differ significantly with respect to gender (p>0.05) except for frontal hypoplasia, which was more often in females (p<0.05).
Conclusion:
Axial and sagittal views using multiplanar reformatted images can be helpful in eliminating artefacts and in identifying variations of the paranasal sinuses. Utilization of soft tissue and bone windows, when necessary, may facilitate evaluation of dehiscence abnormalities.
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