European Journal of Cardiovascular Medicine

Upper airway assessment is critical for safe anaesthetic management, particularly in patients with known or suspected airway abnormalities. Conventional clinical evaluation may not detect subclinical anatomical variations or lesions, posing potential challenges during intubation or ventilation. Moreover, accurate imaging is indispensable in diagnosing and managing laryngeal afflictions, including malignancies, infections, and structural anomalies.

The advent of advanced imaging technologies has revolutionized airway evaluation. CT scans provide high-resolution images of the airway lumen and surrounding structures. MRI offers superior soft tissue contrast, and ultrasound has emerged as a valuable, bedside tool for dynamic assessment. This study aims to evaluate the utility, accuracy, and clinical impact of these imaging modalities in pre-anaesthetic airway evaluation and laryngeal pathology diagnosis.

Study Design and Setting:

This was a prospective observational study conducted over 12 months.

Inclusion Criteria:

• Adult patients (>18 years) scheduled for surgery requiring general anaesthesia
• Patients with clinical suspicion of laryngeal pathology (hoarseness, stridor, dysphonia)

Exclusion Criteria:

• History of previous airway surgery
• Patients unwilling or unable to undergo imaging procedures

Procedure:
All patients underwent standard pre-anaesthetic airway assessment followed by imaging as indicated:

• CT scan for suspected structural anomalies or airway narrowing
• MRI for evaluation of soft tissue masses or laryngeal tumours
• Ultrasound for vocal cord mobility and surface cartilage evaluation

Findings were recorded and correlated with intraoperative and laryngoscopic findings wherever applicable. The primary outcome was the diagnostic yield of imaging in detecting clinically relevant airway or laryngeal abnormalities.

Demographics:
Out of 100 patients, 58 were male and 42 were female, with a mean age of 47.5 years.

Imaging Findings:

• CT was performed in 60 patients and detected significant airway narrowing in 25 cases (41.6%)
• MRI (n=25) identified soft tissue lesions in 17 cases (68%)
• Ultrasound (n=15) revealed impaired vocal cord mobility in 6 patients and thyroid cartilage deformity in 4 patients

Diagnostic Accuracy:

• CT: Sensitivity 93%, Specificity 87%
• MRI: Sensitivity 95%, Specificity 90%
• Ultrasound: Sensitivity 85%, Specificity 80%

Clinical Impact:

• Imaging led to change in anaesthetic plan in 16 cases (16%)
• Confirmed or altered clinical diagnosis in 12 cases (12%)

Table 1: Demographic Characteristics

Table 2: Imaging Modalities Used

Table 3: CT Findings

Table 4: MRI Findings

Table 5: Ultrasound Findings

Table 6: Clinical Impact of Imaging

Table 7: Comparative Imaging Parameters

The master table highlights comparative findings across imaging modalities in four key parameters:

1. Age (years):
   The mean age across all groups (CT: 48.2 ± 9.4; MRI: 46.9 ± 10.2; Ultrasound: 46.0 ± 8.8) was comparable with no statistically significant difference (p = 0.75), indicating age distribution was uniform and did not bias modality selection.
2. Airway Narrowing Cases (%):
   CT detected a significantly higher rate of airway narrowing (41.6 ± 12.5%) compared to MRI (12.0 ± 5.5%) and Ultrasound (0.0 ± 0.0%) with a highly significant p-value (p = 0.001). This confirms CT's superiority in evaluating structural airway compromise.
3. Soft Tissue Lesions (%):
   MRI identified soft tissue lesions in a markedly higher proportion of patients (68.0 ± 15.0%) than CT (5.0 ± 3.0%) or Ultrasound (0.0 ± 0.0%), yielding a highly significant p-value (p = 0.0001). This validates MRI’s enhanced soft tissue contrast for detecting laryngeal pathologies.
4. Vocal Cord Abnormality (%):
   Ultrasound detected vocal cord abnormalities in 66.7 ± 10.2% of cases, significantly outperforming CT (3.3 ± 2.5%) and MRI (0.0 ± 0.0%) (p = 0.0002). This reinforces ultrasound’s utility as a dynamic tool for vocal cord assessment.
   Each imaging modality offers unique strengths—CT for airway narrowing, MRI for soft tissue lesion characterization, and Ultrasound for real-time functional assessment of vocal cords—supporting a tailored, multimodal approach in pre-anaesthetic and laryngeal evaluations.

Our study confirms the indispensable role of imaging in upper airway evaluation. CT remains the gold standard for visualizing bony structures and assessing airway patency. MRI is superior for soft tissue evaluation, making it ideal for tumor characterization. Ultrasound, though operator-dependent, offers dynamic and non-invasive assessment particularly useful in the preoperative setting.

Findings from this study are consistent with previous research suggesting that imaging can significantly alter management strategies and improve patient safety. The choice of modality should be tailored based on clinical presentation, suspected pathology, and availability.

Our study reaffirms the indispensable role of imaging in upper airway evaluation. CT was the most frequently used modality (60%), revealing airway narrowing in 25 of 60 patients (41.6%) and tracheal deviations or subglottic lesions in a smaller subset (Table 3). MRI was employed in 25 cases and revealed soft tissue or neoplastic lesions in 68% of patients (Table 4). These results are consistent with findings reported by Arens and Glanz (1) and Becker et al. (5), who emphasized CT and MRI for superior anatomical clarity.

Ultrasound was valuable in real-time assessment of vocal cord mobility and detected abnormalities in 10 out of 15 patients (Table 5). This supports the utility highlighted in studies by Kristensen (4) and Gupta et al. (2), reinforcing ultrasound's non-invasive application in perioperative airway assessment.

In 28 cases, imaging directly influenced either anaesthetic planning or diagnostic clarity (Table 6), a figure comparable with prior literature where imaging impacted decision-making in 20–30% of patients (6, 9). Moreover, 16% of our patients had a change in anaesthetic plan due to imaging findings, which aligns with Finkelstein et al.’s analysis (3) of preoperative airway challenges.

This evidence supports a multimodal approach. CT remains the gold standard for evaluating fixed obstructions and bone/cartilage anomalies (1, 6). MRI offers better soft tissue differentiation, especially in tumor evaluation (5, 8). Meanwhile, ultrasound remains a practical, bedside adjunct for real-time assessments (4, 10).

Imaging of the upper airway enhances diagnostic precision and improves perioperative safety in patients undergoing general anaesthesia or with suspected laryngeal disorders. Multimodal imaging provides a comprehensive evaluation and should be considered a vital component of pre-anaesthetic assessment and laryngeal pathology workup.

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