ANATOMICAL VARIATION OF NOSE AND PARANASAL SINUSES AMONG PATIENTS WITH CHRONIC RHINOSINUSITIS ON COMPUTER TOMOGRAPHY

paents with CRS ranged from 15-75 years. Highest number of paents with CRS was in the range of 35-44 years. Mucosal thickening was more common in maxillary sinus (91.12%) followed by ethmoidal (67.74%), spheniod (55.64%) and frontal (54.03%). CT scan is the most common tool to know the anatomical variaons of the nose and para nasal sinuses. Moreover it is highly recommended for the paents suﬀering from chronic rhinosinusis. CT scan provides all the sinonasal variaons and then it becomes easier for the treang physician for beer surgical planning and overall management of chronic rhinosinusis.


Introduc on
Chronic rhinosinusi s is one of the commonest diseases of sinonasal cavity seen in Ear nose throat clinic. Although chronic rhinosinusi s is a clinical diagnosis, CT scan imaging studies helps in accessing the disease and gives a clear anatomy of sinonasal cavity. Chronic rhinosinusi s is a group of disorders that is characterized by inflamma on of the mucosa of the nose and paranasal sinuses of at least 12 consecu ve weeks dura on. There are number of factors that play role in the development of rhinosinusi s, including both host and environmental factors. CRS is a more persistent problem that requires a specific treatment approach.

Methodology
This is a prospec ve compara ve study which was conducted in Department of otorhinolaryngology of Birat Medical College and Teaching Hospitalfrom 1st August 2020-31st Dec 2020. This study was approved by Ins tu onal Review Commi ee of Birat Medical College and Teaching Hospital. 124 pa ents were taken in the study. The primary objec ve of the study was to determine the anatomical varia on of nose and paranasal sinuses among pa ents with chronic rhinosinusi s on computer tomography. Informed and wri en consent was taken from all the subjects par cipa ng in the study.

Result
A total of 124 pa ents was included in the study. Out of which 68 (54.76%) were men and 56 (45.24%) were female. The age of pa ents with CRS ranged from 15-75 years. Highest number of pa ents with CRS was in the range of 35-44 years. Mucosal thickening was more common in maxillary sinus (91.12%) followed by ethmoidal (67.74%), spheniod (55.64%) and frontal (54.03%).

Conclusion
CT scan is the most common tool to know the anatomical varia ons of the nose and para nasal sinuses. Moreover it is highly recommended for the pa ents suffering from chronic rhinosinusi s. CT scan provides all the sinonasal varia ons and then it becomes easier for the trea ng physician for be er surgical planning and overall management of chronic rhinosinusi s.

INTRODUCTION
Chronic rhinosinusi s is one of the commonest diseases of sinonasal cavity seen in Ear nose throat clinic. Although chronic rhinosinusi s is a clinical diagnosis, CT scan imaging studies helps in accessing the disease and gives a clear anatomy of sinonasal cavity. Chronic rhinosinusi s is a group of disorders that is characterized by inflamma on of the mucosa of the nose and paranasal sinuses of at least 12 2 consecu ve weeksdura on.
There are number of factors that play role in the development of rhinosinusi s, including both host and environmental factors. CRS is a more persistent problem that requires a specific treatment approach. It is some mes overlooked by both pa ents and healthcare providers because the symptoms are more low-grade and chronic. Endoscopic sinus surgery (ESS) is a frequently performed procedure for chronic rhinosinusi es. Certain anatomic variants are thought to be predisposing factors for the development of sinus diseases and thus it becomes essen al to know about the anatomical varia ons. Detail radiological descrip on of the anatomy and its anatomical varia ons of nose and paranasal sinuses is required before 3 performing the surgery. Numerous sinonasal variants exist and are frequently seen on CT scan. The most common ones are septal devia on, inferior turbinateshypertrophy, concha bullosa, Aggernasi cells, infraorbitalethmoidal (haller) cells, sphenoethmoidal (onodi) cells. Nasal septal devia on is most common and is seen in more than one half of the popula on. Concha bullosa is the pneuma za on of the middle turbinates involving its inferior bulbous and its 4 usually bilateral.

METHODOLOGY
This is a prospec ve compara ve study which was conducted in Department of otorhinolaryngology of Birat Medical College and Teaching Hospital from 1st August 2020-31st Dec 2020. This study was approved by Ins tu onal Review Commi ee of Birat Medical College and Teaching Hospital. 124 pa ents were taken in the study. The primary objec ve of the study was to determine the anatomical varia on of nose and paranasal sinuses among pa ents with chronic rhinosinusi s on computer tomography. Informed and wri en consent was taken from all the subjects par cipa ng in the study. All the pa ents aged above 15 years who underwent CT scan of nose and paranasal sinuses for chronic rhinosinusi s was taken in the study. Age less than 15 years, Pa ents with surgical or trauma c antecedents in sinonasal region, invasive fungal sinusi s, sinonasal malignancies, history of previous sinonasal surgery and those who did not give consentwere excluded from the study. All pa ents underwent plain non contrast computer tomography (NCCT) of Nose and Paranasal sinuses using 64 slice MDCT scanner (Somatom Perspec ve, Siemens, Erlangen, Germany) to see the area of nose and PNS involved using standard protocol of the ins tute from skull base to angle of mouth in supine posi on using 2 mm slice thickness and 32 x 0.2 mm collima on. CT scan was done both for bony and so ssue window. The anatomical varia ons of the nose and paranasal sinus was noted and the data was entered in microso excel and was exported to Microso SPSS 19 for analysis. Frequency, percentage, mean, sensi vity and specificity were calculated.

RESULTS
A total of 124 pa ents was included in the study. Out of which 68 (54.76%) were men and 56 (45.24%) were female. The age of pa ents with CRS ranged from 15-75 years. Highest number of pa ents with CRS was in the range of 35-44 years.     On computer tomography deviated nasal septum was seen in 63.70% more common on the le side (30.64%), inferior turbinate hypertrophy in 50.80%, concho bullosa was seen in 36.29% more common on the le side (14.51%), nasal polyp in 45.96% more common on the right side 20.16%. On clinical examina on most of the pa ents had post nasal drip (44.35%) followed by facial tenderness (32.25%).  In our study popula on the most common presenta on was nasal obstruc on (95.16%) which was followed by headache (87.90%) and nasal discharge (68.54%). Our study 7 is in accordance with the study conducted by Asruddin et al where nasal blockage and nasal discharge was the most frequent symptom followed by headache. Similarly, study 5 by Pandey et al revealed nasal discharge, headache and nasal blockage as the major presen ng symptom in pa ents 8 with CRS. In the study conducted by Kirtane et al the commonest complaint was nasal discharge occurring in 25 pa ents (78.1%) followed by headache in 22 pa ents (68.7%) and nasal obstruc on in 22 (68.7%).
Our studies showed deviated nasal septum as the most common anatomical varia ons which accounted for 67.74% followed by inferior turbinated hypertrophy (50.80%) and concha bullosa (34.67%). Our study is supported by studies 9 conducted by Stallman Et al in which they found 60% and in 10 Mamatha et al it was 65%. Similary the study conducted by 11 Kundan et al in Nepal showed DNS in 64.50% of the popula on. Whereas the prevalence of DNS in study conducted 12 13 by This study is also supported by Dar Lone in which maxilliary 23 sinusi s was the most common presenta on with 70.31%.

CONCLUSION
CT scan is the most common tool to know the anatomical varia ons of the nose and para nasal sinuses. Moreover it is highly recommended for the pa ents suffering from chronic rhinosinusi s. CT scan provides all the sinonasal varia ons and then it becomes easier for the trea ng physician for be er surgical planning and overall management of chronic rhinosinusi s.

RECOMMENDATION
Computer tomography of nose and para nasal sinus is highly recommended in pa ents suffering from chronic rhino sinusi s. It provides all the anatomical varia on and helps the surgeon for surgical planning and minimizing complica on in the pa ents.

LIMITATION OF THE STUDY
This study was conducted in a small group of popula on a ending ENT OPD of Birat Medical College and Teaching Hospital with features of chronic rhino sinusi s. Similar study has to be conducted in large popula on to know the more about the anatomical varia on of nose and para nasal sinuses.

ACKNOWLEDGEMENT
The author would like to thank all the faculty members of Department of Otorhinolaryngology and Radiology for the constant support and mo va on during the research period. The author would also like to acknowledge all the par cipants without whom the study would not have been possible.