Pediatric Airway Foreign Body

Etiology:
— Foreign body below vocal cords in larynx and trachea (15%) or in left mainstem bronchi (23%) or in right mainstem bronchi (60%)
— Causes ball valve effect
— Most common is peanut and peanut is bad because protein incites vicious foreign body reaction
Note: Presence of asymmetric aeration of lungs or asymmetric pulmonary air trapping in child should raise suspicion of aspirated airway foreign body
Note: Goal of imaging at early presentation is to rule out asthma and croup and bronchiolitis and decide who needs bronchoscopy to avoid delayed diagnosis
Imaging at early presentation:
— 90% of foreign bodies are radiolucent
— 33% of inspiratory CXR are normal
— Classically see hyperinflation and mediastinal shift with lack of change in lung volume and asymmetrical air trapping as affected lung does not deflate in expiration or when placed down on decubitus
— Heart swings towards affected side on inspiration (rocker heart)
Imaging at late presentation:
— Atelectasis or pneumonia or abscess
Secondary signs of upper airway foreign body:
— Symmetric lung lucency
— Enlarged hypopharynx
— Retropharyngeal soft tissue swelling
Secondary signs of lower airway foreign body:
— Asymmetric lung lucency, atelectasis, pleural effusion, pneumothorax
DDX: Symptoms overlap with asthma, croup, bronchiolitis
Complications:
Treatment:
Clinical:
— 50-75% present within 24 hours
— Less than 50% have classic triad of wheeze and cough and decreased breath sounds

Radiology Cases of Airway Foreign Body

Radiology Cases of Airway Foreign Body in Pyriform Sinus

Airway radiograph of airway foreign body in the pyriform sinus — Lateral radiograph of the airway shows a linear radiopaque foreign body in the airway anterior to the C2 and C3 vertebral bodies.

Radiology Cases of Airway Foreign Body in Trachea

Radiograph of airway foreign body — Lateral radiograph of the airway shows a subglottic soft tissue mass. Endoscopy showed a sunflower seed surrounded by granulation tissue.

Radiology Cases of Simultaneous Airway Foreign Body in the Trachea and Gastrointestinal Foreign Body in the Esophagus in the Form of an Earing

CXR of a foreign body in the airway and the esophagus in the form of an earing — CXR AP (left) shows a linear radiopaque object projecting over the trachea. CXR lateral (right) shows the anterior portion of the radiopaque object to project over the trachea and its posterior portion to project over the esophagus.

Radiology Cases of Acute Airway Foreign Body in Left Mainstem Bronchus

CXR and CT of foreign body in left mainstem bronchus — CXR AP at presentation (above left) shows mediastinal shift to the left and complete opacification of the left hemithorax due to complete atlectasis of the left lung. A subsequent CXR AP obtained the next day (not provided) showed reexpansion of the left lung which was symmetrically expanded when compared to the right lung. CXR AP obtained 3 months later (above right) showed the left hemithorax to be hyperlucent when compared to the right hemithorax. Axial CT without contrast of the lungs (below) again shows the relative hyperlunceny of the left hemithorax and a foreign body is seen just beneath the carina filling the proximal left mainstem bronchus (below center).

CXR of peanut in left mainstem bronchus — Inspiratory CXR AP (left) is normal and shows the lungs to be clear and to be symmetrically aerated and no radiopaque foreign body is seen. Expiratory CXR AP (right) shows a normal decrease in the volume in the right lung in expiration while there is no decrease in the volume in the left lung in expiration (air trapping) and there is mediastinal shift to the right.

Decubitus CXR of airway foreign body — Right lateral decubitus CXR (left) shows deflation of the right lung when placed in a dependent position. Left lateral decubitus CXR (right) shows lack of deflation of the left lung when placed in a dependent position and note the left lung remains hyperlucent when compared to the right lung.

CXR of airway foreign body in left mainstem bronchus — CXR AP (above) shows hyperlucency of the left lung when compared to the right lung. Right lateral decubitus CXR (below left) shows appropriate collapse of the right lung when placed in a dependent position. Left lateral decubitus CXR (below right) shows inappropriate non-collapse of the left lung when placed in a dependent position.

CXR of foreign body in the left mainstem bronchus — CXR AP shows hyperaeration and increased lucency of the left lung compared to the right lung. There is also mediastinal shift to the right.

Radiology Cases of Chronic Airway Foreign Body in Left Mainstem Bronchus

CXR of chronic airway foreign body in left mainstem bronchus — CXR AP shows extensive atelectasis and consolidation in the lingula and left lower lobe with tracheal and mediastinal shift to the left. There is a small left pleural effusion.

CXR and CT of chronic airway foreign body in the form of a mucous plug — CXR AP and lateral (above) show an opacity in the left upper lobe that was stable over several months. Coronal CT with contrast of the chest (below) shows complete atelectasis of the left upper lobe. There is a soft tissue density present in the lumen of the left mainstem bronchus interrupting the continuity of the left mainstem bronchus. At bronchoscopy this was found to be a very thick mucous plug.

Radiology Cases of Acute Airway Foreign Body in Right Mainstem Bronchus

CXR of airway foreign body — CXR taken in inspiration (above) shows symmetrical aeration of the lungs. CXR taken in expiration (below) shows air trapping in the right lung.

CXR of airway foreign body in right mainstem bronchus — Inspiratory CXR (above) shows normal symmetrical aeration of the lungs bilaterally. Expiratory CXR (below) shows asymmetrical increased aeration (seen as increased lucency) of the right middle and lower lobes compared to the remainder of the lungs due to air trapping in the right middle and lower lobes.

CXR of pulmonary tuberculosis — CXR AP taken in expiration shows hyperinflation of the right lung with mediastinal shift to the left due to asymmetrical air trapping in the right lung on expiration.

Radiology Cases of Chronic Airway Foreign Body in Right Mainstem Bronchus

CXR of chronic airway foreign body due to a screw in the right mainstem bronchus — Initial CXR AP and lateral (above) show symmetrical aeration of the lungs and a radiopaque object in the right mainstem bronchus along with dense opacities in the right middle and right lower lobes. CXR AP obtained after bronchoscopic removal of the foreign body (below) shows persistent opacity in the right middle lobe.

Bronchoscopy Cases of Airway Foreign Body

Bronchoscopic image of airway foreign body — Bronchoscopic image at the level of the carina (above) shows a blue foreign body in the left mainstem bronchus which was pulled out of the airway (middle) and upon removal was found to be a blue crayon (below).