ABSTRACT
This study was carried out to know the frequency of occurrence of common anatomic variants in computed tomography of paranasal sinuses and nasal cavity. Non contrast Computed tomography (CT) of paranasal sinuses of 100 patients referred to Department Of Radiology, Saveetha Medical College were retrospectively studied. The Multi-detector computed tomography (MDCT) scans were evaluated for various anatomical variants of paranasal sinuses and nasal cavity. The frequency of occurrence was calculated in percentage.We found out that deviated nasal septum (DNS) was the most common variant in this study, seen in 86% of cases, followed by Agger nasi cells which was seen in 56% and the third most common was supra-orbital ethmoidal cells seen in 42% of the study population. All the cases included in the study, had minimum of one variant. Most of the study population showed multiple anatomical variations of paranasal sinus and nasal cavity. In conclusion, multidetector Computed tomography plays an important role is the assessment of various anatomical variants of the paranasal sinuses and nasal cavity. Pre-operative MDCT of Paranasal sinuses, gives the surgeons most if not all of the anatomical information they need to tailor surgeries. Considering the relatively high frequency of occurrence of these variants, it is essential for the radiologists to have a precise knowledge of imaging features of normal anatomy and anatomical variants of Paranasal sinuses.
ABSTRACT
Background: Paranasal sinuses are a group of four paired airfilled, mucosa lined spaces surrounding the nasal cavity. Thepneumatization or hypoplasia of the sinuses affects thedrainage pathways, causing chronic infections andcomplications. The aim of the present study was to assess theanatomical variations of paranasal sinuses on computedtomography.Materials and Methods: The present retrospective study wascarried out over the period of 6 months using 80 CBCT imagesof patients, with their age group ranging from 20-50 yearsreferred for different oral diagnostic purposes. An assessmentof paranasal sinuses and it’s variations were accuratelycharacterized in axial, coronal and sagittal sections. The datawas analysed statistically using SPSS 21 software and Chisquare test was used to find the statistical significance.Results: In the present study total participant were 80 in which56.25% were having anatomical variation. 8.75% were havingvariation in agar nasi cells,10% were having variation in Kuhncells, 7.5% were having variation in Onodi cells, 5% werehaving variation in haller cells, 10% were having variation inconcha bullosa, 12.5% were having variation in nasal septumdeviation, 20% were having variation in maxillary sinus septa,17.5% were having variation in sphenoid sinus pnematization,2.5% were having variation in maxillary sinus pnematization,6.25% were having variation in Crista galli pneumatisation.Conclusion: This study concluded that imaging of the PNS willaid in diagnosis in individual patients, and also provide adeeper understanding of the manifestations of the disease.
ABSTRACT
BACKGROUND AND OBJECTIVES: The Onodi cell is the posterior-most ethmoid air cell that lies superior to the sphenoid sinus, and has intimate relationship with the optic nerve. The aim of this study was to evaluate Onodi cell prevalence, protrusion and bony dehiscence of the optic nerve in Korean population using computed tomography (CT). SUBJECTS AND METHOD: A retrospective analysis was performed on 129 Korean patients who consecutively underwent CT between January 2014 and December 2014. The presence of Onodi cells and protrusion and bony dehiscence of the optic nerve were analyzed using 3-dimensional CT images. RESULTS: A total of 70 males and 59 females were studied. Onodi cells were present in 61 (47.3%) patients but in 88 CT slides (34.1%); this consisted of 27 Onodi cells found bilaterally (44.3%), 18 on the right side only (29.5%), and 16 on the left only (26.2%). Of the total 61 patients with Onodi cells, the optic nerve protrusion and dehiscence were present in 34.4% and 23.8% of the studied CT slides. There was no statistically significant relationship between the presence of Onodi cells and protrusion and bony dehiscence of the optic nerve. CONCLUSION: In our study, Onodi cells were found in almost half of the patients. This prevalence is higher than previously reported in the literature. In patients with Onodi cells, the optic nerve protrusion and dehiscence were present in about 1/3 and 1/5 of the total slides, respectively. Therefore, the identification of these cells is essential prior to endoscopic sinus and skull base surgery to prevent potential complications.