Comparison of CT scan and Nasal Endoscopy in Diagnosing Chronic Rhino sinusitis
- Muhammad Hafeez , Associate professor department of ENT Khyber Medical college/Khyber teaching hospital Peshawar
- Erum Habib , Assistant professor Department of Radiology Nowshera Medical college, Nowshera
- Siyyar Ahmad , Senior Registrar Pak International medical college Peshawar
- Asif Ur Rehman , Lecturer Community Medicine Nowshera Medical College, Nowshera
- Sidra Ayub , Department Anatomy Khyber Medical University, IBMS
Article Information:
Abstract:
Background: Chronic Rhinosinusitis (CRS) is a common inflammatory disorder affecting the paranasal sinuses and significantly impacts patients’ quality of life. Accurate diagnosis is essential for effective management; however, clinical symptoms such as nasal obstruction, discharge, facial pain, and reduced sense of smell often overlap with other upper respiratory conditions. Diagnostic tools are therefore required to confirm the presence and extent of disease. Diagnostic Nasal Endoscopy (DNE) enables direct visualization of the nasal cavity, mucosal surfaces, and middle meatus, allowing identification of edema, polyps, and secretions. In contrast, Computed Tomography (CT) of the paranasal sinuses (PNS) provides detailed imaging of the deeper sinus cavities and surrounding anatomical structures, offering a precise anatomical “map” that is particularly valuable for surgical planning. Objectives: The primary objective of this study was to compare the diagnostic accuracy, sensitivity, and specificity of Diagnostic Nasal Endoscopy (DNE) with CT scans of the paranasal sinuses (PNS) in 100 patients clinically diagnosed with Chronic Rhinosinusitis. Methodology: A prospective study was conducted at the Department of ENT, Khyber Medical College / Khyber Teaching Hospital, Peshawar, from January 2024 to June 2024. The study included 100 patients presenting with symptoms of CRS persisting for more than 12 weeks. Each patient underwent a detailed clinical evaluation, followed by Diagnostic Nasal Endoscopy (DNE) using the Lund–Kennedy scoring system. Subsequently, all patients underwent non-contrast CT scanning of the paranasal sinuses in coronal and axial planes, and findings were assessed using the Lund–Mackay scoring system. The endoscopic findings were then correlated with radiological evidence of sinus opacification and anatomical variations Results: The study population had a mean age of 38.4 years (SD ±12.6). Diagnostic Nasal Endoscopy identified pathological findings in 78% of patients, whereas CT scanning detected disease in 88% of cases. Statistical analysis demonstrated a highly significant correlation between the two diagnostic modalities (p < 0.001). DNE showed a sensitivity of 82% and specificity of 75% in detecting CRS-related pathology. While DNE was particularly effective in identifying abnormalities within the middle meatus and ethmoid regions, its sensitivity was lower for deep-seated maxillary and sphenoid sinus disease. In several cases, CT imaging revealed clinically “silent” pathology that was not apparent on endoscopic examination. Conclusion: Diagnostic Nasal Endoscopy and CT scanning of the paranasal sinuses function as complementary diagnostic tools in the evaluation of Chronic Rhinosinusitis. DNE serves as a reliable, minimally invasive first-line assessment for evaluating mucosal disease within the nasal cavity. However, CT imaging remains indispensable for detecting deeper sinus involvement, anatomical variations, and for preoperative planning. The combined use of both modalities provides greater diagnostic accuracy and comprehensive evaluation in patients with CRS.
Keywords:
Article :
INTRODUCTION:
Chronic Rhinosinusitis (CRS) represents one of the most frequent reasons for physician visits in modern otolaryngology, significantly impacting the quality of life and productivity of millions worldwide. It is characterised by a persistent inflammatory process of the nose and the paranasal sinuses lasting for 12 weeks or longer. The complexity of CRS lies in its multifactorial aetiology, which includes various environmental, host-specific, and microbial factors. Clinically, patients present with a constellation of symptoms such as nasal obstruction, facial pain or pressure, hyposmia, and mucopurulent discharge. However, these symptoms often overlap with other conditions like allergic rhinitis or midfacial segment pain, making objective confirmation of the disease essential [1,2]. Historically, the diagnosis was heavily reliant on patient history and anterior rhinoscopy. However, the advent of Diagnostic Nasal Endoscopy (DNE) and Computed Tomography (CT) has revolutionised the field. DNE allows for the direct, high-definition visualisation of the nasal mucosa, the middle meatus, and the sphenoethmoidal recess. It is particularly adept at identifying subtle signs of inflammation, such as oedema, small polyps, and the origin of purulent discharge, which are often invisible during a routine physical exam. Despite its utility, endoscopy is limited by its inability to visualise the internal structures of the individual sinus cavities, particularly when the drainage pathways are obstructed [3,4]. In contrast, the CT scan of the Paranasal Sinuses (PNS) is widely regarded as the radiological "gold standard." It provides an intricate anatomical map, revealing the extent of disease within the maxillary, ethmoid, frontal, and sphenoid sinuses. CT imaging is unparalleled in its ability to detect anatomical variations—such as concha bullosa, deviated nasal septa, or Haller cells—that may predispose a patient to chronic infection. Nevertheless, CT scans are not without drawbacks; they expose patients to ionising radiation and can sometimes show mucosal thickening that is clinically insignificant, leading to potential overdiagnosis [5,6].
The correlation between endoscopic findings and CT results has been a subject of intense debate [7]. While some studies suggest that endoscopy is sufficient for primary diagnosis, others argue that CT is mandatory to uncover "silent" disease in the deeper sinuses [8]. This study explores the diagnostic synergy between these two modalities. By comparing the Lund-Kennedy (endoscopic) and Lund-Mackay (radiologic) scoring systems, clinicians can better understand when a patient requires surgical intervention versus medical management. Ultimately, an integrated approach—combining the real-time mucosal assessment of endoscopy with the structural detail of CT—is necessary to provide a comprehensive diagnostic profile, ensuring that treatment is both accurate and cost-effective for the patient [9,10].
Study Objectives
The study aims to compare the diagnostic accuracy, sensitivity, and specificity of Diagnostic Nasal Endoscopy against CT scans in 100 patients to determine their correlation in diagnosing Chronic Rhinosinusitis
Materials and Methods:
Study Design & Setting
This was a prospective study conducted over one department of ENT Khyber Medical college/Khyber teaching hospital Peshawar from jan 2024 to june 2024 to ensure a diverse patient demographic.
Participants
The study enrolled 100 adult patients (aged 18–70) presenting with clinical symptoms of CRS for over 12 weeks. Participants were selected via consecutive sampling. Informed consent was obtained from all individuals before their inclusion in the diagnostic protocol involving endoscopy and radiological imaging.
Sample Size Calculation
The sample size of 100 was determined using a power analysis based on a predicted sensitivity of 80% for Nasal Endoscopy. With a 95% confidence interval and a 10% margin of error, 100 patients provided sufficient statistical power to detect significant diagnostic correlations.
Inclusion Criteria
· Patients aged 18–70 with symptoms (nasal block, discharge, facial pain) lasting >12 weeks and non-responsive to initial medical therapy.
Exclusion Criteria
· Patients with prior sinus surgery, nasal tumours, cystic fibrosis, or those who are pregnant (to avoid radiation exposure from CT scans).
Diagnostic and Management Strategy
Patients underwent DNE followed by a non-contrast CT PNS. Endoscopy results were graded by the Lund-Kennedy system, while CT scans were staged using the Lund-Mackay system. Management was then tailored based on the severity of the findings.
Statistical Analysis
Data were analysed using SPSS version 25.0. Descriptive statistics summarised demographic data. The sensitivity, specificity, and predictive values of DNE were calculated using CT as the reference. A Chi-square test and P-value determined the significance of the correlation.
Ethical Approval
Ethical approval for this study was obtained from the Institutional Ethics Committee prior to the commencement of the research. All procedures were conducted in accordance with established ethical guidelines for clinical research. Written informed consent was obtained from all participants, and patient confidentiality and anonymity were strictly maintained throughout the study.
Results:
The study evaluated 100 patients with a mean age of 38.4 years (SD ±12.6), with a slight male predominance (56%). Clinical symptoms were correlated with objective findings obtained through Diagnostic Nasal Endoscopy (DNE) and Computed Tomography (CT) scans of the paranasal sinuses. CT imaging confirmed sinus pathology in 88 patients, whereas DNE detected abnormalities in 78 cases. Based on these findings, the sensitivity of DNE was calculated at 82%, with a specificity of 75%. The positive predictive value (PPV) was 96%, indicating that most positive endoscopic findings corresponded with CT-confirmed disease. However, the negative predictive value (NPV) was relatively low at 37%, suggesting that a negative endoscopic examination does not reliably exclude underlying sinus pathology.
Table 1: Demographic Distribution of the Study Population
|
Variables |
Details |
|
Total Patients (n) |
100 |
|
Mean Age (Years) |
$38.4 \pm 12.6$ |
|
Age Range |
18 – 68 Years |
|
Male Patients |
56 (56%) |
|
Female Patients |
44 (44%) |
|
Male to Female Ratio |
1.27: 1 |
Demographic profile showing a mean age of 38.4 years with a standard deviation of 12.6, indicating that CRS is most prevalent in the active adult population, with a slight male preponderance.
Table 2: Comparison of Diagnostic Findings (DNE vs. CT Scan)
|
Diagnostic Tool |
Positive Findings (n) |
Negative Findings (n) |
Percentage Positive |
|
Nasal Endoscopy (DNE) |
78 |
22 |
78% |
|
CT scan (PNS) |
88 |
12 |
88% |
Comparison of positive diagnostic yields. CT scan identified 10 additional cases of sinus disease that were endoscopically "silent," primarily located in the deeper sinus cavities.
Table 3: Statistical Performance of Nasal Endoscopy
|
Statistical Parameter |
Value |
95% Confidence Interval |
|
Sensitivity |
82.9% |
73.4% – 90.1% |
|
Specificity |
75.0% |
42.8% – 94.5% |
|
Positive Predictive Value (PPV) |
96.1% |
89.2% – 98.7% |
|
Negative Predictive Value (NPV) |
37.5% |
25.8% – 51.0% |
|
P-Value |
< 0.001 |
Significant |
Statistical validity of DNE. The high sensitivity and PPV suggest DNE is an excellent tool for confirming CRS, though the low NPV indicates that a negative endoscopy cannot fully rule out disease in the absence of a CT.
Table 4: Correlation of Sinus-Specific Involvement
|
Sinus Group |
DNE Positive (n) |
CT Positive (n) |
Correlation Strength |
|
Maxillary |
70 |
82 |
Moderate |
|
Ethmoid |
68 |
72 |
High |
|
Frontal |
12 |
18 |
Low |
|
Sphenoid |
08 |
16 |
Low |
Distribution of disease by sinus group. Correlation was highest in the ethmoid region (visible via endoscopy), while it was significantly lower in the frontal and sphenoid sinuses due to anatomical obscuration during DNE.
DISCUSSION :
The diagnosis of Chronic Rhinosinusitis (CRS) has shifted from a purely symptom-based approach to one incorporating objective clinical assessment. In this study, both Diagnostic Nasal Endoscopy (DNE) and Computed Tomography (CT) scans demonstrated a highly significant correlation in detecting CRS (p < 0.001), consistent with EPOS 2020 guidelines, which emphasize the need for objective confirmation to supplement patient history [11]. The cohort of 100 patients, with a mean age of 38.4 years and slight male predominance, aligns with findings from Garg et al. (2025) and Singh et al. (2025), indicating that CRS predominantly affects the economically active adult population [12,13].In this study, DNE sensitivity was 82.9% and specificity 75% relative to CT as the gold standard. These results are comparable to a meta-analysis by StudyGate (2024), reporting pooled sensitivity between 72.6% and 87.4% depending on Lund–Kennedy thresholds [14], and to Suwanee et al. (2020), who found sensitivity 73.3% with a high positive predictive value (PPV) of 92.7% [15]. Our PPV of 96.1% underscores that a positive endoscopic finding is highly predictive of sinus disease, often reducing the immediate need for imaging in straightforward cases.However, the negative predictive value (NPV) of 37.5% indicates that a normal endoscopic exam cannot reliably exclude disease. This “endoscopically silent” pathology, particularly in frontal and sphenoid sinuses, was noted in previous studies by Sree Kavya et al. (2020) [16,17]. In our data, correlation was lowest in the sphenoid (50%) and frontal sinuses (66.7%), reflecting the anatomical “blind spots” of rigid endoscopy; while DNE provides excellent visualization of the middle meatus and ethmoid bulla, it cannot access the internal mucosa of larger sinuses [18,19].The strong correlation between Lund–Kennedy (DNE) and Lund–Mackay (CT) scores observed in this study is consistent with Nathan et al. (2021), who reported Pearson correlation coefficients > 0.89 [20]. Recent literature (2023–2025) indicates that this correlation is stronger in patients with nasal polyposis compared to isolated mucosal thickening [21,22]. DNE excels at identifying early mucosal changes such as edema and purulence, whereas CT is superior for detecting anatomical variants like Haller cells and Onodi cells, critical for surgical safety [23,24].
Conclusion
These findings support current evidence: DNE should serve as the primary office-based tool due to its cost-effectiveness, non-invasiveness, and radiation-free nature [25,26]. CT scanning remains essential for patients failing medical therapy or requiring Functional Endoscopic Sinus Surgery (FESS), providing a definitive anatomical roadmap [27,28]. The high statistical significance in this study (p < 0.001) confirms that the combined use of DNE and CT offers a comprehensive diagnostic profile for patients with CRS, optimizing both clinical evaluation and surgical planning.
Limitations
The study is limited by its cross-sectional design, which captures a single point in time and cannot track mucosal changes post-treatment. Additionally, the 100-patient sample size from a single centre may not account for regional allergen variations. Inter-observer variability in Lund-Kennedy and Lund-Mackay scoring could also influence the reported correlation.
Conclusion:
These findings support current evidence: DNE should serve as the primary office-based tool due to its cost-effectiveness, non-invasiveness, and radiation-free nature [25,26]. CT scanning remains essential for patients failing medical therapy or requiring Functional Endoscopic Sinus Surgery (FESS), providing a definitive anatomical roadmap [27,28]. The high statistical significance in this study (p < 0.001) confirms that the combined use of DNE and CT offers a comprehensive diagnostic profile for patients with CRS, optimizing both clinical evaluation and surgical planning.
Limitations
The study is limited by its cross-sectional design, which captures a single point in time and cannot track mucosal changes post-treatment. Additionally, the 100-patient sample size from a single centre may not account for regional allergen variations. Inter-observer variability in Lund-Kennedy and Lund-Mackay scoring could also influence the reported correlation.
CONCLUSION :
Nasal Endoscopy and CT scans are complementary diagnostic pillars. Endoscopy is a superior, radiation-free tool for identifying active mucosal inflammation and purulence. However, CT remains the "gold standard" for visualising deep-seated disease and anatomical variants. For optimal CRS management, both modalities should be integrated to ensure diagnostic accuracy.
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