Sinusitis is the inflammation of a sinus, while rhinitis refers to the inflammation of nasal mucosa membrane. Due to close anatomical relationship between the sinus cavities and nasal passages, as well as their shared respiratory epithelium, both structures are often affected simultaneously. Rhinosinusitis refers to the inflammation of nasal cavities and paranasal sinuses (PNS)1. Rhinosinusitis is referred to as chronic when inflammation of the nasal cavity and PNS persists for 12 weeks or longer, with diagnosis confirmed through objective evaluation2. Epidemiological studies have reported the prevalence of CRS to range from 5% to 12%7. CRS is a public health problem that has a considerable socio-economic impact. Additionally, complexity of the disease, varying underlying pathophysiology stemming from its diversified nature, results in its different variants, making it challenging to fully understand and develop the most effective targeted treatment strategies4. For diagnosing CRS, the AAO-HNS guidelines encompasses both subjective and objective criteria, requiring symptoms to persist for ≥12 weeks. The subjective criteria involve the presence of two or more of the following key symptoms: nasal congestion, anterior and/or posterior mucopurulent discharge, facial pain or pressure and anosmia. The objective criteria include at least one of the following findings: mucus (purulent/non purulent) or edema in the middle meatus or ethmoid region, nasal polyps in middle meatus, or radiological evidence of inflammation in the PNS. A thorough clinical history remains the cornerstone of diagnosis and all patients will undergo a general otorhinolaryngological examination, nasal endoscopy enable detailed examination of the nasal cavity, from the anterior nares to the postnasal space. DNE can be performed in-office under local anaesthesia, it focuses on identifying and assessing key features such as the middle turbinate, middle meatus, OMC, anatomic obstructions, nasal polyps and mucopurulent discharge. CT scan plays an important role in knowing the anatomical relationships between key structures, such as the optic nerve, orbital contents and carotid artery, along with diseased areas, which is essential for surgical planning. Additionally, CT imaging helps determine the extent of disease within individual sinuses and identifies underlying anatomical abnormalities that may predispose a patient to sinusitis8. In this study, we have correlated the DNE findings and CT abnormalities in patients with CRS.

Second Pass: Endoscope was reinserted between inferior turbinate and middle turbinate. The inferior portion of the middle turbinate and meatus, the fontanelles and any accessory ostium were examined. The sphenoethmoidal recess was visualized by passing the endoscope medial to the posterior aspect of middle turbinate and rotating it superiorly. The superior turbinate and the natural sphenoid ostium were often visualized. Third Pass: The endoscope was rotated laterally beneath the posterior aspect of the middle turbinate to gain access to the deeper areas of middle meatus. Bulla ethmoidalis, hiatus semilunaris, infundibular entrance, uncinate process and its overlying mucosa was visualized After DNE, patient had been sent to CT scan of nose and paranasal sinuses. Non contrast CT of nose and PNS was performed using 128 slice CT Scanner (Make GE). This scan aimed to identify areas of persistent chronic inflammation that contribute to recurrent acute infections. Statistical Analysis Descriptive statistics including mean, standard deviation, frequency, and percentages were used to summarized demographic variables, clinical symptoms, and diagnostic findings from DNE and CT scans. Cross-tabulations compared DNE and CT findings, evaluating agreement using odds ratios (OR) with 95% confidence intervals (CI). Chi-square tests determined statistical significance at p<0.05. Diagnostic accuracy measures—sensitivity and specificity were calculated with their 95% CIs, considering CT findings as the reference standard. Analyses were conducted using Statistical Package for Social Sciences (SPSS) IBM version 24.

During the course of study, a total of 70 patients were included. The age of the patients was ranged between 17 and 65 years and maximum patients were of 3rd-4th decade. Mean age of the patients was 39 ± 16 years. Study comprised of 57(81.4%) males and females were 13 (18.6%) with male to female ratio of 4.4:1. Table 1: Symptoms of CRS Symptom Right (%) Left (%) Nasal blockage 70 (100) 67(95.7) Nasal obstruction 61(87.1) 60(85.7) Nasal congestion 59(84.3) 58(82.9) Nasal discharge 68(97.1) 68(97.1) Facial pain 22(31.4) 22(31.4) Facial pressure 32(45.7) 32(45.7) Reduced or loss of smell 28(40) 28(40) The most common symptom observed were nasal blockage on the right side (70 cases,100%) and nasal discharge on the left side (68 cases,97.1%). This was followed by nasal obstruction (61 cases,87.1% on the right side and 60 cases,85.7% on the left side), nasal congestion (59 cases,84.3% on the right side and 58 cases,82.9% on the left side), facial pressure (32 cases,45.7% on both sides), reduced or lost sense of smell (28 cases,40% on both sides), and facial pain (22 cases,31.4% on both sides). (Table 1) Table 2: Clinical findings of CRS on DNE Findings Right side Left side Present (%) Absent (%) Present (%) Absent (%) Mucosa congestion 64 (91.4) 6 (8.6) 64 (91.4) 6 (8.6) Nasal discharge 70 (100) 00 70 (100) 00 Scarring 17 (24.3) 53 (75.7) 17 (24.3) 53 (75.7) Inferior turbinate hypertrophy 41 (58.6) 29 (41.4) 39 (55.7) 31 (44.3) Middle turbinate hypertrophy 34 (48.6) 36 (51.4) 37 (52.8) 33 (47.2) Paradoxically curved middle turbinate 30 (42.8) 40 (57.2) 29 (41.3) 41 (58.7) Abnormal uncinate process 15 (21.4) 55 (78.6) 17 (24.3) 53 (75.7) Nasal polyp 26 (37.1) 44 (62.9) 26 (37.1) 44 (62.9) Frontal recess patency 33 (47.1) 37 (52.9) 33 (47.1) 37 (52.9) Accessory maxillary ostium 23 (32.9) 47 (67.1) 25 (35.7) 45 (64.3) Septal deviation 44 (62.9) 26 (37.1) 50 (71.4) 20 (28.6) Osteomeatal complex occlusion 32 (45.7) 38 (54.3) 37 (52.9) 33 (47.1) The most common DNE finding in CRS cases was bilateral nasal discharge (100%), followed by nasal mucosal congestion (91.4%). Other frequent observations included septal deviation (62.9% right, 71.4% left), inferior turbinate hypertrophy (58.6% right, 55.7% left), middle turbinate hypertrophy (48.6% right, 52.8% left), and frontal recess patency (47.1% bilateral). OMC occlusion was noted in 45.7% (right) and 52.9% (left), paradoxical middle turbinate in 42.8% (right) and 41.3% (left), nasal polyps in 37.1% (bilateral), accessory maxillary ostium in 32.9% (right) and 35.7% (left), scarring in 24.3% (bilateral), and abnormal uncinate process in 21.4% (right) and 24.3% (left) cases (Table 2). Table 3: Findings of CRS on CT scan nose and paranasal sinus Findings Right side Left side Present Absent Present Absent Inferior turbinate hypertrophy 40 (57.14%) 30 (42.86%) 38 (54.29%) 32 (45.71%) Middle turbinate hypertrophy 37 (52.86%) 33 (47.14%) 40 (57.14%) 30 (42.86%) Paradoxically curved middle turbinate 27 (38.57%) 43 (61.43%) 25 (35.71%) 45 (64.29%) Abnormal uncinate process 17 (24.29%) 53 (75.71%) 19 (27.14%) 51 (72.86%) Nasal polyp 26 (37.14%) 44 (62.86%) 26 (37.14%) 44 (62.86%) Frontal recess patency 38 (54.29%) 32 (45.71%) 38 (54.29%) 32 (45.71%) Visualisation of agger nassi 60 (85.71%) 10 (14.29%) 61 (87.14%) 09 (12.86%) Accessory maxillary ostium 23 (32.86%) 47 (67.14%) 25 (35.71%) 45 (64.29%) Septal deviation 42 (60%) 28 (40%) 47 (67.14%) 23 (32.86%) Frontal sinus opacity 33 (47.14%) 37 (52.86%) 29 (41.43%) 41 (58.57%) Anterior ethmoidal sinus haziness 63 (90%) 07 (10%) 61 (87.14%) 09 (12.86%) Posterior ethmoidal sinus haziness 44 (62.86%) 26 (37.14%) 42 (60%) 28 (40%) Sphenoid sinus haziness 38 (54.29%) 32 (45.71%) 36 (51.43%) 34 (48.57%) Maxillary sinus haziness 69 (98.57%) 01 (1.43%) 69 (98.57%) 01 (1.43%) Osteomeatal complex occlusion 30(42.86%) 40(57.14%) 35(50%) 35(50%) CT findings in CRS most commonly showed maxillary sinus haziness (98.6% bilateral), followed by anterior ethmoidal sinus haziness (90% right, 87.1% left). Other frequent observations included agger nasi cells (≈86%), posterior ethmoidal sinus haziness (≈61%), septal deviation (≈64%), inferior and middle turbinate hypertrophy (≈55%), frontal recess patency (54%), sphenoid sinus haziness (≈53%), OMC occlusion (≈46%), frontal sinus opacity (≈44%), paradoxical middle turbinate (≈37%), nasal polyps (37%), accessory maxillary ostium (≈34%), and abnormal uncinate process (≈26%) (Table 3). Table 4: Comparison between DNE and CT scan CT scan Odds Ratio (95% CI) Chi-Square Value (p-value) Present (P) Absent (A) D N E Inferior turbinate hypertrophy Present 72 8 81 (26.54 – 247.20) 88.933 (<0.001) Absent 6 54 Middle turbinate hypertrophy Present 63 8 30.93 (12.07 – 79.27) 66.230 (<0.001) Absent 14 55 Paradoxically curved middle turbinate Present 50 8 250 (51.01 -1225.07) 102.103 (<0.001) Absent 2 80 Uncinate process Abnormal 100 8 87.5 (24.54 – 311.98) 82.899 (<0.001) Normal 4 28 Nasal polyp Present 44 8 55 (19.30 – 156.66) 79.855 (<0.001) Absent 8 80 Frontal recess patency Present 62 4 66.42 (20.68 – 213.29) 79.117 (<0.001) Absent 14 60 Accessory maxillary ostium Present 36 12 20 (8.19 – 48.78) 53.741 (<0.001) Absent 12 80 Septal deviation Present 86 8 154.08 (38.90 – 610.32) 96.285 (<0.001) Absent 3 43 Osteomeatal complex occlusion Present 63 6 362.25 (70.52 -1860.70) 110.160 (<0.001) While comparing DNE findings from the CT scan as mentioned in Table no. 4, each nasal or sinus anatomical feature was evaluated, with observations categorized as "Present" or "Absent" based on CT scan results, and subsequently cross referenced against DNE findings. There is a statistically significant agreement between DNE and CT scan, as reflected by high odds ratios and highly significant chi-square values (p < 0.001). Table-5: Diagnostic accuracy of DNE in comparison to CT scan Findings Similarity Between CT Scan and DNE [n(%)] (Accuracy) Difference Between CT Scan and DNE [n(%)] Inferior turbinate hypertrophy 126 (90.0%) 14 (10%) Middle turbinate hypertrophy 118 (84.28%) 22 (15.72%) Paradoxically curved middle turbinate 130 (92.85%) 10 (7.15%) Uncinate process 128 (91.42%) 12 (8.58%) Nasal polyp 124 (88.57%) 16 (11.43%) Frontal recess patency 122 (87.14%) 18 (12.86%) Accessory maxillary ostium 116 (82.85%) 24 (17.15%) Septal deviation 129 (92.14%) 11 (7.86%) Osteomeatal complex occlusion 132 (94.28%) 8 (5.72%) High diagnostic accuracy values across conditions (ranging mostly between 80% to 95%) suggest strong overall concordance of DNE findings compared to CT, thus reinforcing the utility of DNE as a reliable diagnostic tool. The highest congruence is seen in findings like OMC occlusion (94.28%), paradoxically curved middle turbinate (92.85%), and septal deviation (92.14%), suggesting these are reliably detected by both methods. A lower congruence is observed in findings like accessory maxillary ostium (82.85%), highlighting where discrepancies are more frequent, possibly due to methodological or anatomical visualization limitations of DNE. (Table 5) Table-6: Sensitivity and specificity of DNE in comparison to CT scan Findings True Positive [n(%)] True negative [n(%)] False Positive [n(%)] False Negative [n(%)] Sensitivity (95%CI) Specificity (95%CI) Inferior turbinate hypertrophy 72 (51.42%) 54 (38.58%) 8 (5.72%) 6 (4.28%) 92.31% (84.01% to 97.12%) 87.10% (76.15% to 94.26%) Middle turbinate hypertrophy 63 (45%) 55 (39.28%) 8 (5.72%) 14 (10%) 81.82% (71.38% to 89.69%) 87.30% (76.50% to 94.35%) Paradoxically curved middle turbinate 50 (35.71%) 80 (57.14%) 8 (5.72%) 2 (1.43%) 96.15% (86.79% to 99.53%) 90.91% (82.87% to 95.99%) Uncinate process 100 (71.44%) 28 (20%) 8 (5.72%) 4 (2.86%) 96.15% (90.44% to 98.94%) 77.78% (60.85% to 89.88%) Nasal polyp 44 (31.42%) 80 (57.14%) 8 (5.72%) 8 (5.72%) 84.62% (71.92% to 93.12%) 90.91% (82.87% to 95.99%) Frontal recess patency 62 (44.28%) 60 (42.86%) 4 (2.86%) 14 (10%) 81.58% (71.03% to 89.55%) 93.75% (84.76% to 98.27%) Accessory maxillary ostium 36 (25.72%) 80 (57.14%) 12 (8.57%) 12 (8.57%) 75.0% (60.40% to 86.36%) 86.96% (78.32% to 93.07%) Septal deviation 86 (61.43%) 43 (30.71%) 8 (5.72%) 3 (2.14%) 96.43% (90.46% to 99.30%) 84.31% (71.41% to 92.98%) Osteomeatal complex occlusion 63 (45%) 69 (49.29%) 6 (4.29%) 2 (1.42%) 96.92% (89.32% to 99.63%) 92.00% (83.40% to 97.01% DNE demonstrated high sensitivity for detecting OMC occlusion (96.9%), septal deviation (96.4%), paradoxically curved middle turbinate (96.2%), and abnormal uncinate process (96.2%) compared to CT. High specificity values were also noted, particularly for OMC occlusion (92%), nasal polyp (90.9%), and paradoxically curved middle turbinate (90.9%). Additionally, DNE showed greater specificity for frontal recess patency (93.8%) than CT (Table 6).

The rising prevalence of rhinosinusitis has become a significant health concern, posing ongoing challenges for ENT surgeons in both diagnosis and treatment. A CT scan plays a crucial role in confirming a CRS diagnosis, evaluating its severity, and guiding treatment decisions. It is now considered the gold standard for assessing CRS and planning surgical interventions. Recent guidelines recommend that either a CT scan or a nasal endoscopic evaluation ideally supplemented with photographic or video documentation should be included in any prospective clinical trial, as these methods provide the most objective data for diagnosing CRS. While endoscopic findings are frequently used to support CRS diagnosis, the precise diagnostic value of nasal endoscopy in confirming CRS remains uncertain5. In present study, the most common symptoms were nasal blockage on right side seen in all cases (100%) and nasal discharge in left side seen in 68 cases (97.1%). In comparison, Baruah S et al4 reported nasal discharge (87%) to be the most common symptom followed by nasal obstruction(69.6%) and Deosthale NV et al5 also reported nasal discharge (72.2%) to be the most common symptom, followed by nasal obstruction (64.8%). However, Lohiya SS et al6 found nasal obstruction/congestion (95%) to be the most prevalent symptom, followed by nasal discharge (66%) in their study. Endoscopic techniques for nose and PNS have allowed detailed and complete visualization of sinus disease while minimizing the complications. With the advent of angled scopes, it is possible now to examine and clear disease in the nooks and corners of paranasal sinuses. The most common finding of CRS on DNE was nasal discharge, observed in all cases (100%) on both sides, followed by nasal mucosa congestion seen in 64 cases (91.4%) on both side. In comparison, Lohiya SS et al6 found nasal discharge (47%) to be the most common finding in their study which is consistent to our study. While Baruah S et al4 reported that the most common clinical finding in their study was septal deviation (60%) and Deosthale NV et al5 found polyp (24.07%) to be most common finding in their study. CT scan provides essential preoperative information, helping to assess the extent of the disease, identify anatomical variations, and evaluate the relationship between the sinuses and surrounding structures. In present study, most common finding were maxillary sinus haziness (69 cases,98.57% on both side) followed by anterior ethmoidal sinus haziness (63 cases,90% on right side and 61 cases,87.14% on left side. Baruah S et al4 found maxillary sinus haziness (80%) in most of the cases in their study which is consistent to our study while study conducted by Lohiya SS et al6 found septal deviation (79%) in most of the cases in their study. In the present study, DNE demonstrated high sensitivity and specificity in diagnosing various sinonasal pathologies when compared to CT scan findings. The sensitivity was highest for OMC occlusion (96.9%), septal deviation (96.4%), paradoxically curved middle turbinate (96.2%), and abnormal uncinate process (96.2%), while specificity was highest for frontal recess patency (93.8%), OMC occlusion (92%), nasal polyp (90.9%), and paradoxically curved middle turbinate (90.9%). These findings indicate that DNE remains a reliable, minimally invasive diagnostic tool for evaluating sinonasal diseases. The results are consistent with those of Kumar et al.7, who reported high diagnostic concordance between DNE and CT, especially for OMC obstruction and septal deviation. Similarly, Hazarika et al.8 observed that DNE could effectively identify intranasal pathologies such as turbinate hypertrophy and mucosal congestion with diagnostic accuracy above 90%.Rao et al9 also emphasized the comparable accuracy of DNE and CT in identifying anatomical variations like concha bullosa and paradoxical middle turbinate. However, a few discrepancies were noted, particularly for findings like accessory maxillary ostium, where DNE detection rates were slightly lower. This variation may be attributed to limited visualization in certain anatomical regions or mucosal edema obscuring deeper structures, as also noted by Singh et al.10 Based on the findings, we conclude that DNE is more sensitive and specific in detecting OMC occlusions and paradoxically curved middle turbinates when compared to CT scans. However, there were several cases where various parameters could not be visualized during DNE, including the middle turbinate, nasal polyps, frontal recess patency, and accessory maxillary ostium. This limitation arose because, in some patients, it was impossible to pass the endoscope beyond a certain point due to severe anatomical abnormalities, such as significant nasal septum deviation, a paradoxical middle turbinate, or concha bullosa. In these instances, CT scans proved to be very helpful. 111,12 Overall, DNE is a highly sensitive and specific tool for diagnosing diseases and identifying pathology in areas that are not accessible through routine anterior rhinoscopy. The findings from DNE correlate well with the results from CT scan imaging.

In conclusion, both DNE and CT scan are essential preoperative investigations before undergoing FESS. They help in accurately assessing the extent of sinus disease, identifying anatomical variations, and evaluating the vital relations of the PNS. While DNE provides a real-time assessment of mucosal pathology, CT imaging serves as a ―road map for the surgeon, offering detailed visualization of sinus structures and guiding surgical planning to minimize complications.

1. Desrosiers M, Evans GA, Keith PK, Wright ED, Kaplan A, Bouchard J, Ciavarella A, Doyle PW, Javer AR, Leith ES, Mukherji A. Canadian clinical practice guidelines for acute and chronic rhinosinusitis. Allergy, Asthma & Clinical Immunology. 2011 Dec;7:1-38. 2. Flint PW. Cummings otolaryngology: head and neck surgery. Philadelphia, Pa: Elsevier; 2021. 3. Bachert C, Pawankar R, Zhang L, Bunnag C, Fokkens WJ, Hamilos DL, Jirapongsananuruk O, Kern R, Meltzer EO, Mullol J, Naclerio R. ICON: chronic rhinosinusitis. World Allergy Organization Journal. 2014 Dec;7:1-28 4. Baruah S, Vyas P, Srivastava A. CT scan vs nasal endoscopy findings in the diagnosis of chronic rhinosinusitis—Our experience. Int J Otorhinolaryngol Head Neck Surg. 2019 May;5(3):739-45. 5. Deosthale NV, Khadakkar SP, Harkare VV, Dhoke PR, Dhote KS, Soni AJ, Katke AB. Diagnostic accuracy of nasal endoscopy as compared to computed tomography in chronic rhinosinusitis. Indian Journal of Otolaryngology and Head & Neck Surgery. 2017 Dec;69:494-9. 6. Lohiya SS, Patel SV, Pawde AM, Bokare BD, Sakhare PT. Comparative study of diagnostic nasal endoscopy and CT paranasal sinuses in diagnosing chronic rhinosinusitis. Indian Journal of Otolaryngology and Head & Neck Surgery. 2016 Jun;68:224-9. 7. Kumar S, Gupta N, Sharma R. Diagnostic correlation between nasal endoscopy and CT findings in chronic rhinosinusitis. Indian Journal of Otolaryngology and Head & Neck Surgery. 2018;70(3):345–350. 8. Hazarika P, Singh R, Bhatia S. Comparative study of diagnostic nasal endoscopy and CT scan in evaluation of sinonasal diseases. International Journal of Otorhinolaryngology and Head and Neck Surgery. 2019;5(4):987–992. 9. Rao V, Reddy M, Naik S. Role of diagnostic nasal endoscopy and CT paranasal sinuses in chronic rhinosinusitis: a comparative study. Journal of Clinical and Diagnostic Research. 2020;14(2):MC01–MC05. 10. Singh D, Mehra Y, Kaur J. Correlation between CT and nasal endoscopic findings in chronic rhinosinusitis and anatomical variations of nose. Indian Journal of Anatomy, Radiology and Surgery. 2021;8(1):10–15. 11. Fokkens WJ, Lund VJ, Hopkins C, et al. European Position Paper on Rhinosinusitis and Nasal Polyps 2020. Rhinology Supplement. 2020;58(Suppl S29):1–464. 12. de Loos DD, Lourijsen ES, Wildeman MA, Freling NJ, Wolvers MD, Reitsma S, Fokkens WJ. Prevalence of chronic rhinosinusitis in the general population based on sinus radiology and symptomatology. Journal of Allergy and Clinical Immunology. 2019 Mar 1;143(3):1207-14.