AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT Scan
• MRI
• Nuclear Medicine
• Intervention
• Multimedia
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT Scan
• MRI
• Nuclear Medicine
• Intervention
• Multimedia
• References

Background

Historically, airway foreign bodies have been a major cause of morbidity and mortality in the United States. Although foreign body aspiration most frequently occurs in children, it happens in adults as well. Foreign body aspiration is commonly referred to as a "café coronary."¹

In the United States, approximately 500-2000 deaths occur each year from foreign body aspiration.² Despite advances in radiologic techniques, the diagnosis of foreign body aspiration can be difficult, and endoscopy may be required.

For excellent patient education resources, visit eMedicine's Esophagus, Stomach, and Intestine Center and Procedures Center. Also, see eMedicine's patient education articles Choking, Swallowed Object, and Bronchoscopy.

Pathophysiology

Food items are the most commonly aspirated foreign bodies; peanuts are the most frequently aspirated food. Other aspirated foods include carrots, popcorn, and fruit. Commonly aspirated nonfood items include rubber balloons, plastic toys, teeth, and dental appliances.³

The severity of foreign body aspiration depends on whether the airway obstruction is complete or partial. Complete airway obstruction occurs in the upper airway at levels above the carina; it causes acute onset of respiratory distress in which the patient is unable to speak or cough. Unfortunately, complete airway obstruction may rapidly proceed to death if the foreign body is not immediately dislodged or removed.³

Partial airway obstruction occurs when the upper airway is partially occluded or if the obstruction occurs distal to the carina. Patients with partial airway obstructions may present weeks to months after the foreign body aspiration, and the condition may be diagnosed because of sequelae, such as recurrent pneumonia, persistent cough, hemoptysis, wheezing, or atelectasis.

Most foreign bodies lodge in the peripheral airways that are distal to the larynx and trachea; however, foreign bodies that are large or sharp or that have irregular borders have a greater tendency to become lodged in the larynx or trachea.³

Mortality/Morbidity

• Estimates indicate that in the United States, foreign body aspiration is fatal in 2000 children each year.⁴
• Complications from foreign body aspiration include respiratory distress, asphyxia, cardiac arrest, fever, laryngeal edema, pneumothorax, hemoptysis, pneumonia, bronchiectasis, and bronchial stricture.²

Race

No racial predilection has been reported in the United States.

Sex

For unknown reasons, foreign body aspiration occurs more frequently in boys than in girls, with a male-to-female ratio of 2:1.⁵

Age

• Foreign body aspiration is most common in children aged 6 months to 4 years, a time when they are exploring their surroundings and placing objects into their mouth.³
• Adults with decreased airway protective mechanisms, such as persons with mental retardation, alcoholism, psychoses, or neurologic disorders, also are at risk of aspiration.⁶

Anatomy

Most foreign bodies become lodged in the right mainstem bronchus, distal to the larynx and trachea. Reasons for this include the following³:

• The diameter of the right main bronchus is larger than the left.
• The angle of divergence from the tracheal axis is smaller on the right.
• Airflow through the right lung is greater than it is through the left.
• The carina is more likely to be located to the left of midline rather than to the right; however, large and irregularly shaped foreign bodies are more likely to become lodged in the laryngeal inlet.

Clinical Details

Foreign body aspiration may appear as an acute onset of respiratory distress, or patients may have a silent presentation manifested by secondary complications. Most patients with foreign body aspiration present with an acute onset of choking, respiratory distress, cyanosis, severe coughing, and wheezing.⁷ A history of aspiration often is lacking, and patients may present days to weeks after the event. On examination, patients may have stridor, crackles, wheezing, decreased breath sounds in the affected lung, or normal results on pulmonary physical examination.

Typical symptoms of complete airway obstruction that occurs while a person is eating a meal include severe respiratory distress and the inability to speak or cough. Individuals typically place their thumbs and index fingers around their neck.³

Patients with partial airway obstruction may present with a sudden onset of coughing, difficulty in breathing, wheezing, or stridor while eating a meal. Unfortunately, a history consistent with foreign body aspiration is usually available in only 70% of patients. After the acute episode of airway distress, patients may continue to experience episodes of persistent coughing and wheezing, or they may become asymptomatic. Moreover, some patients experience recurrent episodes of pneumonia in the same topographic area. Other patients develop complications, such as hemoptysis, bronchiectasis, and bronchial stricture.²

Preferred Examination

When foreign body aspiration is suspected in a patient, screening radiographic studies employed include anteroposterior (AP) and lateral imaging of the soft tissues of the neck, inspiratory and expiratory posteroanterior (PA) chest radiographs (CXRs), and lateral CXRs. Lateral decubitus chest radiography, fluoroscopy, or both may help in diagnosing foreign body aspiration in patients who are unable to cooperate with inspiratory and expiratory CXRs. If findings are negative for foreign bodies in all radiographic studies and if the clinical suspicion still remains high, bronchoscopy should be performed in the operating room by an airway endoscopist for definitive diagnosis and treatment.

Limitations of Techniques

Radiopaque foreign bodies are easy to diagnose by using radiographs. With radiolucent foreign bodies, secondary radiographic signs, such as obstructive emphysema, atelectasis, pneumonia, and a mediastinal shift, help in diagnosing foreign body aspiration.⁸

DIFFERENTIALS

Section 3 of 10  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT Scan
• MRI
• Nuclear Medicine
• Intervention
• Multimedia
• References

Other Problems to Be Considered

Arteriovenous malformation
Atelectasis
Bacterial tracheitis
Carcinoma
Croup (laryngotracheobronchitis)
Epiglottitis
Esophageal foreign body
Granuloma
Papilloma
Retropharyngeal abscess
Tracheal mucus

RADIOGRAPH

Section 4 of 10  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT Scan
• MRI
• Nuclear Medicine
• Intervention
• Multimedia
• References

Findings

Initial radiographic studies should include AP and lateral views of the soft tissues of the neck, PA CXRs obtained during inspiration and expiration, and lateral CXRs. The depiction of radiopaque foreign bodies is straightforward. Obtaining 2 views of the foreign body helps in determining its location and excludes the presence of superimposed multiple foreign bodies. Most foreign bodies are radiolucent; therefore, indirect radiologic findings must often be obtained.

• Radiolucent tracheal foreign bodies may show signs of an infraglottic opacity or of swelling from airway inflammation on PA and lateral neck radiographs.⁹
• Patients with bronchial foreign bodies may have normal findings on CXRs; however, the affected lung may show hyperaeration (obstructive emphysema) and shifting of the mediastinum away from the affected lung on expiratory CXRs because of the ball-valve effect of the tracheal foreign body (see Images 1-2). In such cases, the patients can inspire air past the foreign body but have difficulty exhaling.
• In patients who are unable to cooperate for expiratory imaging (eg, young children), decubitus CXR or fluoroscopy may show hyperaeration and mediastinal shifting. Decubitus CXRs reveal failure of the affected lung to collapse, even if the patient is in the decubitus position (see Image 3).
• Images in patients with chronic bronchial foreign bodies may show atelectasis, with a mediastinal shift toward the foreign body and/or recurrent pneumonias in the affected lung segment (see Images 4-5).

Degree of Confidence

Plain radiographic results cannot exclude foreign body aspiration. If the clinical suspicion is high for foreign body aspiration, endoscopy should be performed for definitive diagnosis and treatment.

False Positives/Negatives

Svedström and colleagues studied the accuracy of CXRs in the diagnosis of tracheobronchial foreign bodies.¹⁰ Of the 34 patients from whom a foreign body was removed, preoperative CXRs showed airtrapping in 50%, atelectasis in 12%, and signs of infection in 18%. Normal CXR findings were obtained in 24% of patients who had endoscopically verified airway foreign bodies. The authors concluded that the diagnostic accuracy, sensitivity, and specificity of CXRs were 67%, 68%, and 67%, respectively. These results show that CXRs alone are neither sensitive nor specific enough to exclude tracheobronchial foreign bodies.

In their study of patients with laryngotracheal foreign bodies, Esclamado and colleagues reported that 92% of neck radiographs showed an infraglottic density or swelling.⁹ In contrast, 58% of the patients in their study who had laryngotracheal foreign bodies had normal CXR findings. These results suggest that PA and lateral neck radiographs should be part of the radiographic workup when foreign body aspiration is a concern.

CT SCAN

Section 5 of 10  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT Scan
• MRI
• Nuclear Medicine
• Intervention
• Multimedia
• References

Findings

As a result of its greater contrast resolution, computed tomography (CT) scanning has been used to demonstrate airway foreign bodies that are radiolucent on plain radiographs.¹¹ Many authors recommend using narrow windows when imaging the thorax, to decrease the likelihood of missing a foreign body.¹²

In addition to providing plain radiographic findings, such as hyperlucency, atelectasis, and lobar consolidation, CT scans can depict the foreign body within the lumen of the tracheobronchial tree and the 3-dimensional position of the foreign body within the thorax.^{11, 13}

Current state-of-the-art helical multidetector-row CT scanners may improve the sensitivity of radiologic evaluation in patients who are unable to cooperate for inspiration and expiration radiography. These scanners may be useful with young children and with adults suffering from an altered level of consciousness.

Degree of Confidence

If CT scans demonstrate signs of foreign body aspiration, the patient should undergo endoscopy for definitive diagnosis and treatment. No further radiologic study is indicated.

False Positives/Negatives

Any process that causes obstruction or narrowing of the airway lumen can produce signs similar to those of foreign body aspiration. Examples include neoplastic disease, granulomatous disease, bronchial stenosis, and a mucus plug.

MRI

Section 6 of 10  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT Scan
• MRI
• Nuclear Medicine
• Intervention
• Multimedia
• References

Findings

Many authors have reported on the use of magnetic resonance imaging (MRI) in identifying aspirated peanuts.^{8, 14, 15, 16} Using T1-weighted images, these authors demonstrated the presence of peanuts via the direct depiction of the high signal intensity emitted by their fat content surrounded by low-intensity lung tissue. Imaizumi and colleagues reported that peanuts can be clearly distinguished from the surrounding areas of granulation and atelectasis because of their hyperintensity on T1-weighted images.¹⁷

The advantages of MRI include its noninvasive nature and the lack of radiation exposure from this modality. MRI also offers high-resolution multiplanar images of soft tissue.⁸

The disadvantages of MRI include its cost, the long data-acquisition time, the need for sedation in some patients, and the necessity to remove all metallic devices from patients.⁸

Degree of Confidence

As with all imaging modalities, if clinical suspicion of an airway foreign body remains high, endoscopy should be performed for definitive diagnosis and treatment.

NUCLEAR MEDICINE

Section 7 of 10  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT Scan
• MRI
• Nuclear Medicine
• Intervention
• Multimedia
• References

Findings

Leonidas and colleagues used perfusion lung scans to demonstrate areas of decreased ventilation that resulted from tracheobronchial foreign bodies.¹⁸ (Decreased ventilation causes reflex vasoconstriction.)

Degree of Confidence

Perfusion defects, or ventilation-perfusion (V/Q) mismatches, are not specific for the presence of airway foreign bodies. Asthma, tuberculosis, emphysema, pneumonitis, and neoplasms may cause perfusion defects.¹⁹ If clinical suspicion for foreign body aspiration is high, further evaluation with endoscopy is warranted.

INTERVENTION

Section 8 of 10  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT Scan
• MRI
• Nuclear Medicine
• Intervention
• Multimedia
• References

Once an aspirated foreign body is diagnosed by using radiographic findings, or if the clinical suspicion is high, the patient should undergo endoscopy for foreign body removal. Endoscopy should be performed in the controlled setting of an operating room by personnel trained in airway foreign body removal.

Medical/Legal Pitfalls

• The potential is great for morbidity and mortality resulting from an aspirated foreign body; hence, if foreign body aspiration is suspected, the appropriate radiographic studies should be performed.
• As a result of the limitations of radiographic studies in the diagnosis of aspirated foreign bodies, all patients in whom the clinical suspicion for aspirated foreign bodies is high should undergo endoscopy for definitive diagnosis and treatment.

MULTIMEDIA

Section 9 of 10  

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT Scan
• MRI
• Nuclear Medicine
• Intervention
• Multimedia
• References

Media file 1:  Inspiratory chest radiograph in a 12-month-old boy with a 2-month history of wheezing demonstrates moderate hyperlucency and hyperexpansion of the right hemithorax. A mild deviation of the mediastinum toward the left chest is noted. Courtesy of Brit B. Gay, Jr, MD, Radiology Department, Egleston Children's Hospital, Atlanta, Ga.
	View Full Size Image
Media type:  X-RAY

Media file 2:  Expiratory chest radiograph in a 12-month-old boy with a 2-month history of wheezing demonstrates continued hyperlucency and hyperexpansion of the right hemithorax. A greater mediastinal shift is noted toward the left lung field. A corn kernel was removed from the patient's right mainstem bronchus during bronchoscopy. Courtesy of Brit B. Gay, Jr, MD, Radiology Department, Egleston Children's Hospital, Atlanta, Ga.
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Media type:  X-RAY

Media file 3:  Left lateral decubitus chest radiograph demonstrates failure of collapse in an 11-month-old girl with a 2-week history of persistent coughing. A corn kernel was found in the patient's left mainstem bronchus during bronchoscopy. Courtesy of Brit B. Gay, Jr, MD, Radiology Department, Egleston Children's Hospital, Atlanta, Ga.
	View Full Size Image
Media type:  X-RAY

Media file 4:  Chest radiograph in a 6-year-old boy who complained of chest pain and dysphagia. Complete atelectasis of the left lung is noted, with a mediastinal shift towards the left lung. Courtesy of Brit B. Gay, Jr, MD, Radiology Department, Egleston Children's Hospital, Atlanta, Ga.
	View Full Size Image
Media type:  X-RAY

Media file 5:  Chest radiograph obtained 2 days after a piece of popcorn was removed from the patient's left mainstem bronchus. Resolution of the atelectasis is complete, and the mediastinum is in its normal position. Courtesy of Brit B. Gay, Jr, MD, Radiology Department, Egleston Children's Hospital, Atlanta, Ga.
	View Full Size Image
Media type:  X-RAY

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Differentials
• Radiograph
• CT Scan
• MRI
• Nuclear Medicine
• Intervention
• Multimedia
• References

1. Mittleman RE, Wetli CV. The fatal cafe coronary. Foreign-body airway obstruction. JAMA. Mar 5 1982;247(9):1285-8. [Medline].
2. Limper AH, Prakash UB. Tracheobronchial foreign bodies in adults. Ann Intern Med. Apr 15 1990;112(8):604-9. [Medline].
3. Tan HK, Brown K, McGill T, et al. Airway foreign bodies (FB): a 10-year review. Int J Pediatr Otorhinolaryngol. Dec 1 2000;56(2):91-9. [Medline].
4. Aytac A, Yurdakul Y, Ikizler C, et al. Inhalation of foreign bodies in children. Report of 500 cases. J Thorac Cardiovasc Surg. Jul 1977;74(1):145-51. [Medline].
5. Rothmann BF, Boeckman CR. Foreign bodies in the larynx and tracheobronchial tree in children. A review of 225 cases. Ann Otol Rhinol Laryngol. Sep-Oct 1980;89(5 Pt 1):434-6. [Medline].
6. Kavanagh PV, Mason AC, Muller NL. Thoracic foreign bodies in adults. Clin Radiol. Jun 1999;54(6):353-60. [Medline].
7. Silva AB, Muntz HR, Clary R. Utility of conventional radiography in the diagnosis and management of pediatric airway foreign bodies. Ann Otol Rhinol Laryngol. Oct 1998;107(10 Pt 1):834-8. [Medline].
8. Kimura H, Aso S, Asai M, et al. Magnetic resonance imaging of an inhaled peanut. Ann Otol Rhinol Laryngol. Jul 1996;105(7):574-6. [Medline].
9. Esclamado RM, Richardson MA. Laryngotracheal foreign bodies in children. A comparison with bronchial foreign bodies. Am J Dis Child. Mar 1987;141(3):259-62. [Medline].
10. Svedström E, Puhakka H, Kero P. How accurate is chest radiography in the diagnosis of tracheobronchial foreign bodies in children?. Pediatr Radiol. 1989;19(8):520-2. [Medline].
11. Newton JP, Abel RW, Lloyd CH, et al. The use of computed tomography in the detection of radiolucent denture base material in the chest. J Oral Rehabil. Mar 1987;14(2):193-202. [Medline].
12. Berger PE, Kuhn JP, Kuhns LR. Computed tomography and the occult tracheobronchial foreign body. Radiology. Jan 1980;134(1):133-5. [Medline]. [Full Text].
13. Zissin R, Shapiro-Feinberg M, Rozenman J, et al. CT findings of the chest in adults with aspirated foreign bodies. Eur Radiol. 2001;11(4):606-11. [Medline].
14. Kitanaka S, Mikami I, Tokumaru A, et al. Diagnosis of peanut inhalation by MRI. Pediatr Radiol. 1992;22(4):300-1. [Medline].
15. O'Uchi T, Tokumaru A, Mikami I, et al. Value of MR imaging in detecting a peanut causing bronchial obstruction. AJR Am J Roentgenol. Sep 1992;159(3):481-2. [Medline].
16. Morijiri M, Seto H, Kageyama M, et al. Assessment of peanut aspiration by MRI and lung perfusion scintigram. J Comput Assist Tomogr. Sep-Oct 1994;18(5):836-8. [Medline].
17. Imaizumi H, Kaneko M, Nara S, et al. Definitive diagnosis and location of peanuts in the airways using magnetic resonance imaging techniques. Ann Emerg Med. Jun 1994;23(6):1379-82. [Medline].
18. Leonidas JC, Stuber JL, Rudavsky AZ, et al. Radionuclide lung scanning in the diagnosis of endobronchial foreign bodies in children. J Pediatr. Oct 1973;83(4):628-31. [Medline].
19. Rudavsky AZ, Leonidas JC, Abramson AL. Lung scanning for the detection of endobronchial foreign bodies in infants and children. Clinical and experimental studies. Radiology. Sep 1973;108(3):629-33. [Medline].
20. Abramson AL, Rudavsky AZ. Use of lung scanning for the detection of endobronchial foreign bodies. Clinical and experimental studies. Ann Otol Rhinol Laryngol. Dec 1972;81(6):832-9. [Medline].
21. Adler OB, Rosenberger A. Localization of metallic foreign bodies in the chest by computed tomography. J Comput Assist Tomogr. Oct 1982;6(5):955-7. [Medline].
22. Alford BR, Chenault DI, Danziger J. Detection of foreign bodies with computerized tomography. Arch Otolaryngol. Apr 1979;105(4):203-4. [Medline].
23. Assefa D, Amin N, Stringel G, et al. Use of decubitus radiographs in the diagnosis of foreign body aspiration in young children. Pediatr Emerg Care. Mar 2007;23(3):154-7. [Medline].
24. Baharloo F, Veyckemans F, Francis C, et al. Tracheobronchial foreign bodies: presentation and management in children and adults. Chest. May 1999;115(5):1357-62. [Medline]. [Full Text].
25. Bissonnette RT, Connell DG, Fitzpatrick DG. Preoperative localization of low-density foreign bodies under CT guidance. Can Assoc Radiol J. Dec 1988;39(4):286-7. [Medline].
26. Darrow DH, Holinger LD. Aerodigestive tract foreign bodies in the older child and adolescent. Ann Otol Rhinol Laryngol. Apr 1996;105(4):267-71. [Medline].
27. Darrow DH, Holinger LD. Foreign bodies of the larynx, trachea, and bronchi. Pediatr Otolaryngol. 1996;2:1390-401.
28. Davis SW, Heitmiller RF, Davis F, et al. Intrapulmonary foreign body simulating pulmonary AVM: CT findings. J Comput Assist Tomogr. Sep-Oct 1997;21(5):769-70. [Medline].
29. Franquet T, Gimenez A, Roson N, et al. Aspiration diseases: findings, pitfalls, and differential diagnosis. Radiographics. May-Jun 2000;20(3):673-85. [Medline]. [Full Text].
30. Gencer M, Ceylan E, Koksal N. Extraction of Pins from the Airway with Flexible Bronchoscopy. Respiration. May 3 2007;[Medline].
31. Gupta AK, Berry M. Detection of a radiolucent bronchial foreign body by computed tomography. Pediatr Radiol. 1991;21(4):307-8. [Medline].
32. Hoeve LJ, Rombout J, Pot DJ. Foreign body aspiration in children. The diagnostic value of signs, symptoms and pre-operative examination. Clin Otolaryngol. Feb 1993;18(1):55-7. [Medline].
33. Ikeda M, Himi K, Yamauchi Y, et al. Use of digital subtraction fluoroscopy to diagnose radiolucent aspirated foreign bodies in infants and children. Int J Pediatr Otorhinolaryngol. Dec 1 2001;61(3):233-42. [Medline].
34. Ikeda M, Kitahara S, Inouye T. Large radiolucent tracheal foreign body found by CT scan caused dyspnea: an admonition on flexible fiberscopic foreign body removal. Surg Endosc. Feb 1996;10(2):164-5. [Medline].
35. Inglis AF Jr, Wagner DV. Lower complication rates associated with bronchial foreign bodies over the last 20 years. Ann Otol Rhinol Laryngol. Jan 1992;101(1):61-6. [Medline].
36. Kjhns LR, Borlaza GS, Seigel RS, et al. An in vitro comparison of computed tomography, xeroradiography, and radiography in the detection of soft-tissue foreign bodies. Radiology. Jul 1979;132(1):218-9. [Medline].
37. Latifi X, Mustafa A, Hysenaj Q. Rigid tracheobronchoscopy in the management of airway foreign bodies: 10 years experience in Kosovo. Int J Pediatr Otorhinolaryngol. Dec 2006;70(12):2055-9. [Medline].
38. Little DC, Shah SR, St Peter SD, et al. Esophageal foreign bodies in the pediatric population: our first 500 cases. J Pediatr Surg. May 2006;41(5):914-8. [Medline].
39. Lue AJ, Fang WD, Manolidis S. Use of plain radiography and computed tomography to identify fish bone foreign bodies. Otolaryngol Head Neck Surg. Oct 2000;123(4):435-8. [Medline].
40. Malis DJ, Hayes DK. Retained bronchial foreign bodies: Is there a role for high-resolution computed tomography scan?. Otolaryngol Head Neck Surg. Feb 1995;112(2):341-6. [Medline].
41. Man DW, Engzell UC, Hadgis C, et al. An unusual laryngeal foreign body in an infant. J Otolaryngol. Apr 1986;15(2):127-9. [Medline].
42. Wolkove N, Kreisman H, Cohen C, et al. Occult foreign-body aspiration in adults. JAMA. Sep 17 1982;248(11):1350-2. [Medline].
43. Zerella JT, Dimler M, McGill LC, et al. Foreign body aspiration in children: value of radiography and complications of bronchoscopy. J Pediatr Surg. Nov 1998;33(11):1651-4. [Medline].

Article Last Updated: Aug 23, 2007