Oral Cavity: The Pharynx


Oral Cavity: The Pharynx

Table 4.40 Pharyngeal/prevertebral soft-tissue swelling




Normal: anterior buckling (expiration±flexion) in the ear lobe

Lateral radiograph: “pseudothickening”—if neck not adequately extended or flexed may get artificially thickened soft tissue in younger children.

Adenoid tonsil

Fig. 4.144

Lateral radiograph: soft-tissue pad in posterior nasopharynx causing narrowing of airway. Sagittal MRI: Soft-tissue mass in nasopharynx. High signal on T2.

If enlarged, causes obstructive sleep apnea.

If > 12 mm, it is abnormal.

Palatine tonsil

Fig. 4.145

Lateral radiograph: prominent soft-tissue mass overlying posterior inferior aspect of soft palate.

MRI: bilateral enlarged high signal masses on T2.

If enlarged, causes obstructive sleep apnea.

Trauma/hematoma ± fracture

Fig. 4.146

Lateral radiograph: prevertebral soft-tissue swelling is greater than the width of vertebral body ± fracture, ± spondylothesis. Atlas dens interval (ADI) may be > 5 mm. Basion-dens interval may be > 12 mm. Power ratio > 1 in atlantoccipital dissociation. Sagittal MRI: prevertebral soft-tissue swelling/hematoma. Retroclival hematoma and blood between basion and dens implies apical/alar ligament disruption. Check tectorial ligament and posterior ligaments. May have associated cord edema.

Prepontine blood seen on NECT should alert to possible cervical spine injury with retroclival hematoma; urgent MRI is indicated even in face of normal lateral cervical spine radiograph.


Lateral radiograph: (patient upright) enlargement of epiglottis and thickening of aryepiglottic folds.

CT (rarely indicated): enlarged, edematous epiglottis and aryepiglottic folds.

Medical emergency—complete airway obstruction may occur at any time. “Thumb” sign.

Retropharyngeal abscess

Fig. 4.147

Fig. 4.148

Lateral radiograph: widening of retropharyngeal soft tissue, ± gas, or air-fluid level. Loss of normal cervical lordosis.

CECT: identifies extent of disease and drainable collections, which are hypodense with rim enhancement.

Cellulitis more common than abscess.

Mass effect on the airways may cause respiratory compromise.

Foreign body

Lateral radiograph: only if radiopaque.

May require contrast swallow postremoval to check for leak.

Lingual thyroid

CT: hyperdense, well-circumscribed mass at base of tongue that enhances strongly with contrast.

MRI: T1—increased signal compared to tongue.

T2—increased signal.

Enhances with contrast.

Nuclear medicine (NM): positive technetium-99m pertechnetate uptake confirms ectopic thyroid.

A 1–3 cm well-circumscribed, round/ovoid, midline/paramedian tongue base mass.

Important to look for normal cervical thyroid tissue, which may be absent.


US: oval homogenous nodes of varying sizes, ± central hypoechogenicity if forming abscess

CECT: well-defined homogenous masses with variable enhancement; ± linear enhancement of hilum of node; ± ring enhancement with hypodense center representing phlegmon or early abscess; ± perinodal fat stranding.

MRI: homogenous signal intensity unless suppurative.

Nonneoplastic enlargement of nodes may be reactive or associated with infection.

Waldeyer ring may be enlarged.

Important to assess adjacent jugular vein for thrombosis.

Fig. 4.144 T1 midline sagittal MRI of nasopharynx shows posterior nasopharyngeal soft-tissue isointense mass consistent with an adenoid tonsil.
Fig. 4.145 Nasopharyngeal soft-tissue mass consistent with a palatine tonsil on lateral radiograph of neck.
Fig. 4.146 T2 midline sagittal MRI neck shows a large hypointense retroclival hematoma displacing an intact tectorial ligament posttrauma. Note increased basion-dens interval and prevertebral soft-tissue edema.
Fig. 4.147 Lateral radiograph of the neck shows massive prevertebral soft-tissue swelling with prominent air-fluid level consistent with a retropharyngeal abscess.
Fig. 4.148 Retropharyngeal abscess. Axial postcontrast CT of suprahyoid neck shows left ring-enhancing abscess with hypodense center in prevertebral space displacing the carotid sheath laterally and causing mild airway compression.

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Jul 12, 2020 | Posted by in PEDIATRIC IMAGING | Comments Off on Oral Cavity: The Pharynx
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