radiographic evaluation of stridor in...

Suhas

RadhakrishnaHarvard Medical School, Year III

Gillian Lieberman, MD

Radiographic Evaluation of Stridor

in Children

Focusing on Infectious Causes

Suhas Radhakrishna, HMS IIIGillian Lieberman, MD


2

Overview

Clinical BasicsRadiographic AnatomyPatient Cases


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Clinical Basics

Stertor: inspiratory

snoring nose, nasopharynx, oropharynx

Stridor: low to medium pitch soundInspiratory = extrathoracic airway obstruction

Expiratory = intrathoracic obstruction


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Sites of Obstruction

NasopharynxOropharynx

and

HypopharynxSupraglotticGlotticSubglotticTracheobronchial

1

Reynolds, P., Abrahams, P. McKinn’s

Interactive Clinical Anatomy –

Head and Neck. CD ROM. Mosby 1996.


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Differential Diagnosis

Congenital AnomaliesTrauma or IntubationForeign BodyInfection and InflammationNeoplasm

“CT FIN”


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Examining the Upper Airway Radiologically

Neck “soft tissue” Plain Films4 views

Inspiratory and expiratoryAP and Lateral

Extension of neck if possible for best view

If patient is in severe respiratory distress, need to intubate

and transfer to ICU

CT / MRI for better visualization


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Normal Radiographic Anatomy-

Lateral

TongueNasopharynx

OropharynxHypopharynx

Approach to Films: Survey the Entire Airway

UvulaTonsils/ “Adenoids”

Retropharynx

Larynx RegionTracheaEsophagus




Stram, E. “Bacterial Tracheitis.” Boston Children’s Hospital Teaching File Case 6-291


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Normal Radiographic Anatomy –

Lateral Coned down view of larynx

EpiglottisAryepiglottic foldsHyoid Bone

Vallecula

TongueVestibular FoldVocal Fold

Sinus/Ventricle of LarynxVestibule of Larynx




Meschan, I. “The Respiratory System.” An Atlas of Normal Radiographic Anatomy. Chapter 10. WB Saunders, 1959



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Normal Radiographic Anatomy -

Frontal

vallecula

EpiglottisAryepiglottic

Folds

Arytenoid

Cartilage

Vestibular CordVocal Cord

Ventricle SubglottisGlottis



Gray’s Anatomy

Patient HP

6 mo old female presents with fever and respiratory distress x 1 dayOn exam

Stable vital signsNontoxic appearing? Inspiratory stridor, + subcostal retractions

Elevated WBC (18.49)Differential includes viral URI, bronchiolitis, PNA, croupChest and neck films were orderedChest film shows no evidence for PNA



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Patient HP –

Lateral filmNormal retropharyngeal soft tissue width

Anatomy:

Posterior Tongue

Vallecula

Epiglottis

Aryepiglottic fold

Glottis / Vocal Cords

Subglottic region hazy with suggestion of narrowing Courtesy of Dr. Maryellen Sun

Patient HP –

Frontal Film

Tracheal DeviationNormal in infants

Subglottic Stenosis

Diagnosis?Croup

Courtesy of Dr. Maryellen Sun


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Normal vs Croup

Normal Croup

Normal “shoulder” “Steeple” sign

Kandarpa, K. “Normal vs Croup” Boston Children’s Hospital Teaching File Case 5-273


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Radiographic Differential Diagnosis

Assymetric

Swischuk, L. and John, S. Differential Diagnosis in Pediatric Radiology. Second Edition, Williams and Wilkins 1995, Baltimore Maryland.

Patient JW

4 y/o

boy presented to ED with 6 day hx of headache and 5 day hx

of bilateral

swollen and sore neck and fever to 103.6.Poor PO intake, trouble turning head, new cough, mild stridor, snoring at night.Exam showed bilateral cervical LADWBC 27.04

Patient JW –

CT scan

Tracheal deviation and compression

Retro- pharyngeal

abscess

See any hypodense

areas that could represent edema or inflammation?

Courtesy of Raymond Mak, HMS IV


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Plain Film Diagnosis of Retropharyngeal Abscess Lateral coned down view

Normally there is a “step off” from the hypo-

pharynx to the larynx.

Step-

off

This is due to the soft tissue density of the undistended

esophagus posterior to the tracheal air column.

In a retropharyngeal abscess there is obliteration of the step off, due to the swelling of the posterior space into the hypopharynx.

Normal RP abscess




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Retropharyngeal Fakeout

Patient was crying!

Beware the fakeout:Crying, expiration, and swallowing can look like a retropharyngeal soft tissue swelling.

Retropharyngeal abscess?

Courtesy of Dr. Maryellen Sun


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Radiographic Differential Diagnosis

Swischuk, L. and John, S. Differential Diagnosis in Pediatric Radiology.

Second Edition, Williams and Wilkins 1995, Baltimore Maryland.


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Patient JF

4 y/o

boy who had a 1 wk history of URI.1 day prior to admission he had: fever to 105 F, cough, stridor, drooling, and vomiting.Let us compare JF’s

normal follow up

film from next year to JF’s

film from today.

Patient JF

JF todayJF next year (normal film)

Hypopharynx Dilation

Epiglottis and Aryepiglottic

Folds Thickening

Subglottic trachea Normal

C-spineStraightened, leaning forward

Normal lordosis

Diagnosis?EpiglottitisRetropharynx

Normal

Hankins, Carol. Boston Children’s Hospital Teaching File Case 5-272


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Patient S

2 ½ year old boy2 week history of URI1 day history of dysphagia

and

temperature to 104 F.He arrives at 6:30 am and neck films are taken.

Patient S Lateral Film

6:30 amThere is a suggestion of epiglottic

thickening and the rest of the film appears normal



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Patient S11:30 amJust 5 hours later…

Our patient S is now in significant distress, extending his neck in a struggle to breathe

The epiglottis and aryepiglottic

folds are

markedly thickened

The glottic

region is hazy and inflamed

The subglottic

trachea and retropharyngeal space appear normal.

Diagnosis?Epiglottitis

He needs immediate intubation!



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Epiglottitis

Fakeouts

“Omega” EpiglottisNormal variantNote thin aryepiglottic

foldBuckling on poor inspiration



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Differential Diagnosis


Patient JO

6 year old girl with a 2 day history of fever to 102 F and sore throatPhysical exam appears normalNeck films are obtained


Patient JO –

Frontal Film

Tracheal narrowing

Subglottic

stenosis

Stram, E. “Boston Children’s Hospital Teaching File Case 6-291


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JO-

Lateral Neck Soft Tissue Film

Normal appearing epiglottis;thickening of aryepiglottic

fold

Subglottis

dense and hazy

Tracheal “Pseudomembrane” –

Strand of exudate

Diagnosis?Bacterial Tracheitis

Stram, E. Boston Children’s Hospital Teaching File Case 6-291


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Summary of Infectious Causes of Stridor

Age Infants to preschool

Prodrome

URI

+ + +/-Toxicity

Microbiology Viral S aureusC diphtheria

H. influenzaS. aureus

Radiographic Findings

“Steeple” on AP = Subglottic

narrowingDilated hypopharynx

Subglottic

narrowingIrregular tracheal marginPseudomembranes

“Thumb sign” = Thickened epiglottic

and aryepiglottic

folds

Treatment MistEpinephrine Steroids

Artificial AirwayAntibiotics

Artificial AirwayAntibiotics

++++

Croup Bacterial Tracheitis Epiglottitis

Modified from Rudolph, A. Fundamentals of Pediatrics. Third Edition. Mc-Graw

Hill, 2002.


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Acknowledgments

Dr. Maryellen SunDr. Gillian LiebermanPamela LepkowskiLarry Barbaras, WebmasterRaymond Mak, HMSShreya

Kangovi, HMS


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ReferencesBingam, Brian J MBChB, FRCS. Atlas of Clinical Otolaryngology. Mosby –

Year Book, Inc , 1992Bellet, P. The Diagnostic Approach to Symptoms and Signs in Pediatrics. Second Edition. Lippincott Williams & Wilkins, 2002. Hankins, Carol. “Epiglottitis.” Boston Children’s Hospital Teaching File Case 5-272.Kandarpa, K. “Normal vs Croup” Boston Children’s Hospital Teaching File Case 5-

273.Kushner, D. “Obstructing Lesions of the Larynx and Trachea in Infants and Children”. Radiologic Clinics of North America. Vol

XVI, No 2, August 1978. Lefebvre, J. Clinical Practice in Pediatric Radiology, The Respiratory System. Volume 2. Masson Publishing USA Inc 1979.Reynolds, P., Abrahams, P. McKinn’s


Head and Neck. CD ROM. Mosby 1996.Rudolph, A. Fundamentals of Pediatrics. Third Edition. Mc-Graw

Hill, 2002.Stram, E. “Bacterial Tracheitis.” Boston Children’s Hospital Teaching File Case 6-291.Swischuk, L. and John, S. Differential Diagnosis in Pediatric Radiology.

Second Edition, Williams and Wilkins 1995, Baltimore Maryland.Zawin, J. “Epiglottitis.” Boston Children’s Hospital Teaching File Case 5-272.Meschan, I. “The Respiratory System.” An Atlas of Normal Radiographic Anatomy. Chapter 10. WB Saunders, 1959.

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