Peds Airway

Front 1

Primary imaging evaluation of the pediatric airway for acute conditions

Back 1

-frontal and lateral of the airway
-frontal and lateral chest

Front 2

Acute upper airway obstruction DDx

Back 2

Presents with stridor
Things to evaluate: epiglottis, aryepiglottic folds, subglottic trachea, and retropharyngeal soft tissues.
DDx:
-Croup
-Epiglottitis
-Exudative tracheitis
-Retropharyngeal cellulitis/abscess
-Foreign bodies

Front 3

Croup (acute laryngotracheobronchitis)

Back 3

-Most common cause of acute upper airway obstruction in young children
-Peak is 6 mos to 3 yrs
-In children older than 3 yrs, other causes of upper airway obstruction should be sought
-Parainfluenza 1
-Usually benign, self limited
-Barky cough, inspiratory stridor
-Inhaled corticosteroids
-Radiographs to exclude other causes of upper airway obstruction
-Frontal radiograph best: loss of the normal shoulders of the subglottic trachea secondary to symmetric subglottic edema
-Narrow portion extends more inferiorly than the pyriform sinuses (inverted V or church steeple)
-Lateral radiographs may show narrowing or loss of definition of the lumen of the subglottic trachea, or hypopharyngeal overdistention
-Epiglottis and aryepiglottic folds appear normal

Front 4

Epiglottitis

Back 4

-Life threatening
-H. influenza (most prevented with vaccine)
-Stridor
-Older than with croup, peak incidence at age 3.5 yrs
-Should NEVER make a child with this lie supine against their will for a radiograph because it can result in acute airway obstruction
-Lateral radiograph: marked enlargement of the epiglottis and thickening of the aryepiglottic folds (normally convex downwards...when thickened, appear convex upwards)
-Normal epiglottis can appear enlarged if obliqued (look at folds!)
-Symmetric subglottic narrowing can be seen on the frontal x ray

Front 5

Exudative tracheitis (bacterial tracheitis)

Back 5

-potentially life threatening
-Purulent infection of the trachea, exudative plaques form along the tracheal walls
-Older than with standard croup, more ill (6-10 yrs)
-Multimicrobial infections
-Linear soft tissue filling defect (a membrane) seen within the airway is most characteristic. Plaquelike irregularity of the tracheal wall is also highly suspicious.
-Mucus may minic a membrane (get them to cough, repeat view)
-Symmetric or asymmetric subglottic narrowing in a child too old to have croup, and irregularity or loss of definition of the tracheal wall.
-If a membrane is sloughed, may cause airway occlusion.
-Should be evaluated endoscopically if suspected, membranes stripped, and elective intubation performed

Front 6

Retropharyngeal cellulitis/abscess

Back 6

-Retropharyngeal cellulitis: pyogenic infection of the retropharyngeal space that usually follows recent pharyngitis or URTI
-Most are young, 6-12 mos
-Lateral xray: thickening of the retropharyngeal soft tissues
-Soft tissues in posterior pharynx should not exceed the diameter of the vertebral body in infants/children
-But, in infants who have short necks, common to see pseudothickening of the retropharyngeal soft tissues if the neck is not well extended
-Apex anterior convexity of the retropharyngeal soft tissues provides supportive evidence that there is true widening
-If unclear, put neck in full extension and repeat
-The only radiographic feature that will diff cellulitis from abscess is air
-Often CT is performed

Front 7

Lower airway obstruction DDx

Back 7

-Bronchiolitis (asthma, viral illness)
-Intrinsic to airway: foreign body, tracheomalacia, or intrinsic masses
-Extrinsic compression of the trachea: vascular rings
-If the xray suggests intrinsic abN, bronchoscopy is next step. If extrinsit abN, cross sectional imaging.
-Initial radiographic test for wheezing is frontal/lateral chest and frontal/lateral airway radiographs

Front 8

Extrinsic lower airway compression DDx

Back 8

Any mediastinal mass
Vascular causes:
-Double aortic arch
-Anomalous left pulmonary artery
-Innominate artery compression syndrome
-Enlargement of the ascending aorta (i.e. Marfans)
-Enlargement of the pulmonary artery (i.e. congenital absence of pulmonary valve)
-Enlargement of the left atrium
Abnormal chest wall configuration (i.e. narrow thoracic inlet)
-A normal trachea never has a wider transverse than AP diameter!

Front 9

Double aortic arch

Back 9

-Persistence of both the left and right fourth aortic arches
-The most common symptomatic vascular ring
-Usually presents soon after birth, usually an isolated lesion
-The two arches compress the trachea anteriorly and the esophagus posteriorly
-The right arch is usually dominant, and higher
-If the right is dominant, the left is ligated via a left thoracotomy
-If the left is dominant, the right is ligated via a right thoracotomy
-Cross sectional imaging to determine dominant arch
-Symmetric take off of four great arteries from the superior aspect of the arches

Front 10

Pulmonary sling

Back 10

Anomalous origin of the left pulmonary artery from the right pulmonary artery
-Passes between the trachea and esophagus (only vascular anomaly that does this!)
-the only vascular anomaly that causes airway compression and asymmetric lung inflation on chest radiographs.
-can be associated with congenital heart disease, complete tracheal rings, and anomalous origin of the right bronchus.
-If complete tracheal rings are present, the rings are typically superior to the pulmonary sling, and the trachea appears very small in caliber and round at the level of the rings.

Front 11

Right aortic arch with aberrant left subclavian artery

Back 11

-Airway compression typically occurs when there is a persistent ductus ligament completing the ring (but can't see this on imaging)
-Often, dilatation of the SC artery at the origin (Kommerell diverticulum), which can contribute to airway compression
-Midline descending aorta as it crosses from right to left can also cause airway compression

Front 12

Innominate artery compression syndrome

Back 12

-The innominate artery passes immediately anterior to the trachea just inferior to the level of the thoracic inlet. Can be narrowing of the trachea at this level in infants due to crowding by thymus
-'syndrome" means symptomatic cases
-compression decreases as the child grows, sx for severe symptoms
-Anterior compression of trachea on lateral film more superior than other vascular impressions!
-CT shows a flattened trachea with the innominate artery immediately anterior to it at the level of the thoracic inlet!

Front 13

Intrinsic lower airway abnormalities

Back 13

-Tracheomalacia
-Tracheal stenosis
-Foreign bodies
-Focal masses

Front 14

Tracheomalacia

Back 14

-Tracheal wall softening related to abnormality of the cartilaginous rings of the trachea
-Can be primary or secondary, results in intermittent collapse of the trachea
-Dx cannot be made on a single static radiograph
-Lateral fluoroscopy or endoscopy can demonstrate dynamic changes in the caliber of the trachea, and they are diagnostic

Front 15

Tracheal masses

Back 15

-Most common: hemangiomas. Most commonly occur in the subglottic region, and often associated with facial hemangiomas in a beard distribution, and appear on frontal radiographs with asymmetric subglottic narrowing.
-Tracheal papilloma
-Tracheal granuloma

Front 16

Airway foreign bodies

Back 16

-Bronchus is most common site of lodgment
-Radiographic findings: asymmetric lung aeration, hyperinflation, oligemia, atalectasis, lung consolidation, pneumothorax, and pneumomediastinum
-97% are radioopaque!
-Key finding is the lack of change in lung volume in different phases of the respiratory cycle (insp/exp views)
-In uncooperative kids, air trapping can be detected in bilateral decubitus views of the chest or by fluoroscopy

Front 17

Asymmetric lucent lung DDx

Back 17

Bronchial foreign body
Swyer-James syndrome
Pulmonary hypoplasia

Front 18

Tonsils

Back 18

-Palatine tonsils can be evaluated on physical exam
-Lateral radiographs are to evaluate the adenoid tonsils: convex soft tissue masses in the posterior nasopharynx, greater than 12 mm in diameter. If very enlarged, can obstruct the nasopharynx. Absent at birth, rapidly proliferate during infancy, and reach their maximal size when children are between 2-10 yrs. Begin to decrease in size during the second decade.
-Palatine tonsils: if enlarged, appear as enlarged soft tissue masses projecting over the posterior aspect of the soft palate
-Enlarged adenoids/palatine tonsils can cause obstructive sleep apnea
-Can do an MRI sleep study with cine clips
-Recurrent and enlarged adenoid tonsils: adenoids can grow back after tonsillectomy. One of the most common causes of recurrent OSA after T and A. After adenoid resection, see a v-shaped defect in the midportion of the adenoid tonsils (at the level of the nasopharynx) on CT/MRI
-Palatine tonsils do NOT grow back after T and A. No published range of normal size for palatine tonsils. Enlarged: "kissing' tonsils at the level of the oropharynx.
-Lingual tonsils: enlarged: single dumbbell shaped mass at the posterior aspect of the tongue. Enlargement can occur following T and A.

Front 19

Congenital airway obstruction
(CHAOS: congenital high airway obstruction syndrome)

Back 19

-in utero laryngeal atresia
-subglottic stenosis
-head and neck masses, most commonly vascular malformations and teratomas
-Fetal imaging findings include: massive increases in lung volumes, flattened or everted hemidiaphragms, hydrops, and polyhydramnios.
-may be delivered via EXIT (ex utero intrapartum treatment): the head is delivered via a c-section, and the airway is established by tracheotomy or intubation prior to the babe being taken off of placental circulation.