Use of Computed Tomography (CT scan) for delineating anatomy and variation of frontal Sinus before Functional Endoscopic Sinus Surgery

For Functional Endoscopic Sinus Surgery (FESS), the surgeon needs an accurate depiction of the anatomy of paranasal sinuses and their variations. Computed tomography (CT Scan) fulfills this requirement by providing detailed anatomy, the anatomical variants, and the extent of the disease in and around the Para nasal sinuses. The aim of this study is to show the anatomy of the Frontal sinus as delineated by the computed tomography. Materials and Methods: STUDY DESIGN: Cross section Descriptive Study. Out of 337 patients above 12 years of age who were referred for computed tomography of paranasal sinuses in the Dept. of Radio- Diagnosis, Govt. Medical College and Hospital from December 2015 till October 2017, 200 adults(males and females) were randomly selected.Of the 200 subjects studied 37(18.5%) subjects had hypoplastic/ non or poorly pneumatised frontal sinuses of which 31 (15.5%) were bilateral and 6 (3%) were unilateral i.e. on right side. Observations and results: Intra frontal cell were seen in about 64 (32%) subjects of which 26 (13%) on right side, 24 (12%) were on left side and 14 (7%) were bilateral. Extension of pneumatisation into crista galli was seen in 16 (8%) subjects and into orbital roof was seen in 6 (3%) subjects. Conclusion: The findings in this study show that anatomical variations in the Para nasal sinuses and nasal cavity are common. Computed tomography is fundamental radiologic investigation for diagnosis of the Sino nasal lesions or pre and post-surgical assessment.