What X-ray view is recommended for assessing adenoids?

Lateral X-Ray View for Adenoid Assessment

The lateral neck radiograph (lateral soft tissue nasopharynx view) is the standard X-ray projection for evaluating adenoid size in children. 1

Radiographic Technique

The lateral view visualizes the sphenoid sinus and adenoids in children, providing a profile view of the nasopharyngeal airway. 1 This projection allows measurement of the adenoid-to-nasopharynx (A/N) ratio, which quantifies the degree of airway obstruction by comparing adenoid tissue size to the nasopharyngeal airway space at the level of the choanae. 2, 3, 4

Clinical Utility and Limitations

However, lateral neck radiography has significant limitations and should only be used selectively, not routinely, when considering adenoidectomy. 2

Key Performance Characteristics:

• Sensitivity: 79.41% and specificity of 75% for detecting adenoid hypertrophy 5
• The A/N ratio shows no correlation with patient symptoms or endoscopic findings in multiple studies 2
• Static radiographs fail to capture the dynamic nature of adenoid obstruction during breathing 6

When Lateral Neck X-Ray May Be Useful:

• As supplemental information when clinical findings are unclear and do not clearly point toward adenoid hypertrophy as the primary cause of nasal obstruction 4
• A 65% nasopharyngeal airway obstruction (two standard deviations below the mean for moderately obstructive adenoids) can serve as a simplified cut-off indicating clinically relevant adenoid enlargement 4
• Values ≥94% obstruction correlate with severely obstructive adenoids, while 78% correlates with moderately obstructive disease 4

Superior Alternative: Nasal Endoscopy

Nasal endoscopy is the more accurate method for assessing adenoid size, with sensitivity of 87.10% and better correlation with symptom severity than radiography. 5, 6 Dynamic video rhinoscopy shows significant correlation between percentage of airway occlusion and total symptom scores (r = 0.367, p = 0.039), while lateral neck radiography measurements show no such correlation. 6

Clinical Decision Algorithm:

1. Start with clinical assessment using symptom questionnaires and Nasal Obstruction Index scores, which correlate well with endoscopic findings (r = 0.621, P < 0.0001) 2
2. Perform nasal endoscopy when available, as it provides direct visualization and dynamic assessment 5, 6
3. Reserve lateral neck radiography for situations where endoscopy is unavailable or when additional objective data is needed in unclear cases 3, 4

Common Pitfalls to Avoid

• Do not rely solely on lateral neck X-ray to make adenoidectomy decisions, as radiographic findings frequently do not correlate with symptoms or endoscopic findings 2
• Avoid ordering routine preoperative lateral neck films when clinical assessment and endoscopy already clearly indicate adenoid hypertrophy 2
• Do not use X-ray measurements alone without considering the clinical picture, as static images miss dynamic airway changes during respiration 6