pneumothorax imaging

8/12/2019 Pneumothorax Imaging

1/19

emedicine.medscape.com

eMedicine Specialties > Radiology > Chest

Pneumothorax ImagingFahad M Al-Hameed, MD, FRCPC, AmBIM, FCCP, FRCPC,Deputy Chairman of Intensive CareDepartment, Consultant in Critical Care and Pulmonary Medicine, King Khalid National GuardHospital, King Abdulaziz Medical City, Saudi ArabiaSat Sharma, MD, FRCPC,Professor and Head, Division of Pulmonary Medicine, Department ofInternal Medicine, University of Manitoba; Site Director, Respiratory Medicine, St Boniface GeneralHospital; Bruce Maycher, MD,Director of Pulmonary Radiology, St Boniface General Hospital;

Associate Professor, Department of Radiology, University of Manitoba

Updated: Dec 11, 2008

Introduction

Pneumothorax, the presence of air within the pleural space, is considered to be one of the most

common forms of thoracic disease. It is classified as spontaneous (not caused by trauma),

traumatic, or iatrogenic (see the images below).[1,2,3 ]

A large, right-sided pneumothorax has occurred from a rupture of a

subpleural bleb.
http://emedicine.medscape.com/http://emedicine.medscape.com/http://emedicine.medscape.com/http://emedicine.medscape.com/


2/19

A true pneumothorax line. Note that the visceral pleural line is observed

clearly, with the absence of vascular marking beyond the pleural line.

Spontaneous pneumothorax may be either primary (occurring in persons without clinically or

radiologically apparent lung disease) or secondary (in which lung disease is present and

apparent). Most individuals with primary spontaneous pneumothorax (PSP) have unrecognized

lung disease; many observations suggest that spontaneous pneumothorax often results fromrupture of a subpleural bleb.

Traumatic pneumothorax is caused by penetrating or blunt trauma to the chest, with air entering

the pleural space directly through the chest wall, through visceral pleural penetration, or through

alveolar rupture resulting from sudden compression of the chest.

Iatronic pneumothorax results from a complication of a diagnostic or therapeutic intervention.

With the increasing use of invasive diagnostic procedures, iatrogenic pneumothorax likely will

become more common, although most cases are of little clinical significance.Complications of pneumothorax

In most reported series, the rate of recurrence of spontaneous pneumothorax on the same side

is as much as 30%; on the contralateral side, the rate of recurrence is approximately 10%.

Other complications include the following:


3/19

Reexpansion pulmonary edema

Bronchopleural fistula - Occurs in 3-5% of patients

Pneumomediastinum and pneumopericardium

Tension pneumothorax may occur after spontaneous pneumothorax, although it is morecommon after traumatic pneumothorax or with mechanical ventilation.

Preferred examination

Chest radiography is the first investigation performed to assess pneumothorax, because it is

simple, inexpensive, rapid, and noninvasive; however, it is much less sensitive than chest

computed tomography (CT) scanning in detecting blebs or bullae or a small

pneumothorax.[4,5,6,7,8,9,10 ]

Radiography

The diagnosis of pneumothorax is established by demonstrating the outer margin of the visceral

pleura (and lung), known as the pleural line, separated from the parietal pleura (and chest wall)

by a lucent gas space devoid of pulmonary vessels. The pleural line appears in the image

below).




4/19

The pleural line may be difficult to detect with a small pneumothorax unless high-quality

posteroanterior and lateral chest films are obtained and viewed under a bright light. A skin fold

may mimic the pleural line; usually, the patient is asymptomatic (see the image below).

Note that although a skin fold can mimic a subtle pneumothorax, lung

markings are visible beyond the skin fold.

In erect patients, pleural gas collects over the apex, and the space between the lung and the

chest wall is most notable at that point (see the image below).


5/19

A large, right-sided pneumothorax has occurred from a rupture of a

subpleural bleb.

In the supine position, the juxtacardiac area, the lateral chest wall, and the subpulmonic region

are the best areas to search for evidence of pneumothorax (see the image below). The

presence of a deep costophrenic angle on a supine film may be the only sign of pneumothorax;

this has been termed the deep sulcus sign.


6/19

Deep sulcus sign in a supine patient in the ICU. The pneumothorax is

subpulmonic.

When a suggested pneumothorax is not definitively observed on an inspiratory film, an

expiratory film may be helpful. At end expiration, the constant volume of the pneumothorax gas

is accentuated by the reduction of the hemithorax, and the pneumothorax is recognized more

easily. Similar accentuation may be obtained with lateral decubitus studies of the appropriate

side (for a possible left pneumothorax, a right lateral decubitus film of the chest should beobtained, with the beam centered over the left lung).

The most common radiographic manifestations of tension pneumothorax are mediastinal shift,

diaphragmatic depression, and rib cage expansion (see the image below).


7/19


8/19

Right main stem intubation resulting in left-sided tension pneumothorax,

right mediastinal shift, deep sulcus sign, and subpulmonic pneumothorax

Pleural effusions occur coincident with pneumothorax in 2025% of patients, but they usually

are quite small. Hemopneumothorax occurs in 23% of patients with spontaneous

pneumothorax. Bleeding is believed to represent rupture or tearing of vascular adhesions

between the visceral and parietal pleura as the lung collapses.

False positives/negatives

Differentiating the pleural line of a pneumothorax from that of a skin fold, clothing, tubing, or

chest wall artifact is important. Careful inspection of the film may reveal that the artifact extends

beyond the thorax or that lung markings are visible beyond the apparent pleural line. In the


9/19

absence of underlying lung disease, the pleural line of a pneumothorax usually parallels the

shape of the chest wall (see the images below).



Note that although a skin fold can mimic a subtle pneumothorax, lung

markings are visible beyond the skin fold.

Artifactual densities usually do not parallel the course of the chest wall over their entire length.


10/19

Avascular bullae or thin-walled cysts may be mistaken for a pneumothorax. The pleural line

caused by a pneumothorax usually is bowed at the center toward the lateral chest wall. Unlike in

pneumothorax, the inner margins of bullae or cysts usually are concave rather than convex and

do not conform exactly to the contours of the costophrenic sulcus. A pneumothorax with a

pleural adhesion also may simulate bullae or lung cysts.Computed Tomography

CT scanning of the chest is being used with increasing frequency in patients with

pneumothorax. CT may be necessary to diagnose pneumothorax in critically ill patients in whom

upright or decubitus films are not possible.

As indicated in a study by Warner et al, CT scanning may prove helpful in predicting the rate of

recurrence in patients with spontaneous pneumothorax. The authors found that patients with

larger or more numerous blebs, as demonstrated on thoracic CT, are more likely to experiencerecurrences. [7 ]

CT demonstrates focal areas of emphysema in more than 80% of patients with spontaneous

pneumothorax, even in lifelong nonsmokers. These areas are situated predominantly in the

peripheral regions of the apex of the upper lobes. (In patients in whom emphysema is not

apparent on CT, it often is evident at surgery or on pathologic examination.)

Degree of confidence

In a study by Mitlehner et al of 35 patients with PSP, localized emphysema with or without bulla

formation was identified on CT in 31 patients (89%) and on radiographs in 15 patients (43%). [4

]Abnormal findings were observed in the lung ipsilateral to the pneumothorax on 28 CT scans

(80%) and on 11 chest radiographs (31%); abnormal findings were observed in the contralateral

lung on 23 CT scans (66%) and on 4 chest radiographs (11%). In most patients, the abnormal

findings consisted of a few localized areas of emphysema (n


11/19

Media file 1: A large, right-sided pneumothorax has occurred from a

rupture of a subpleural bleb.

Media file 2: A true pneumothorax line. Note that the visceral pleural line is

observed clearly, with the absence of vascular marking beyond the pleural

line.


12/19

Media file 3: Note that although a skin fold can mimic a subtle

pneumothorax, lung markings are visible beyond the skin fold.


13/19

Media file 4: Deep sulcus sign in a supine patient in the ICU. The

pneumothorax is subpulmonic.

Media file 5: An older man admitted to ICU postoperatively. Note the right-

sided pneumothorax induced by the incorrectly positioned small-bowel

feeding tube in the right-sided bronchial tree. Marked depression of the

right hemidiaphragm is noted, and mediastinal shift is to the left side,

suggestive of tension pneumothorax. The endotracheal tube is in a good

position.


14/19

Media file 6: Right main stem intubation resulting in left-sided tension

pneumothorax, right mediastinal shift, deep sulcus sign, and subpulmonic

pneumothorax


15/19

Media file 7: Pneumomediastinum from barotrauma may result in tension

pneumothorax and obstructive shock.


16/19

Media file 8: A patient in ICU developed pneumopericardium as a

manifestation of barotrauma.

References

1. Light RW. Pleural Diseases. 3rd ed. Baltimore: Williams & Wilkins;1995.

2. Sahn SA, Heffner JE. Spontaneous pneumothorax. N Engl J Med. Mar

23 2000;342(12):868-74.[Medline].

3. Tschopp JM, Rami-Porta R, Noppen M, Astoul P. Management of spontaneous

pneumothorax: state of the art. Eur Respir J. Sep 2006;28(3):637-50.[Medline].

4. Mitlehner W, Friedrich M, Dissmann W. Value of computer tomography in the detection

of bullae and blebs in patients with primary spontaneous

pneumothorax. Respiration. 1992;59(4):221-7.[Medline].
http://www.medscape.com/medline/abstract/10727592http://www.medscape.com/medline/abstract/16946095http://www.medscape.com/medline/abstract/1485007http://www.medscape.com/medline/abstract/1485007http://www.medscape.com/medline/abstract/16946095http://www.medscape.com/medline/abstract/10727592


17/19

5. Lesur O, Delorme N, Fromaget JM, et al. Computed tomography in the etiologic

assessment of idiopathic spontaneous pneumothorax. Chest. Aug 1990;98(2):341-

7.[Medline].

6. Slater A, Goodwin M, Anderson KE, Gleeson FV. COPD can mimic the appearance ofpneumothorax on thoracic ultrasound. Chest. Mar 2006;129(3):545-50.[Medline].

7. Warner BW, Bailey WW, Shipley RT. Value of computed tomography of the lung in the

management of primary spontaneous pneumothorax.Am J Surg. Jul 1991;162(1):39-

42.[Medline].

8. Barnes TW, Morgenthaler TI, Olson EJ, Hesley GK, Decker PA, Ryu

JH. Sonographically guided thoracentesis and rate of pneumothorax. J Clin

Ultrasound. Dec 2005;33(9):442-6.[Medline].

9. Chung MJ, Goo JM, Im JG, Cho JM, Cho SB, Kim SJ. Value of high-resolution

ultrasound in detecting a pneumothorax. Eur Radiol. May 2005;15(5):930-5.[Medline].

10. Reissig A, Kroegel C. Accuracy of transthoracic sonography in excluding post-

interventional pneumothorax and hydropneumothorax. Comparison to chest

radiography. Eur J Radiol. Mar 2005;53(3):463-70.[Medline].

Keywords

pneumothorax, spontaneous pneumothorax, primary spontaneous pneumothorax, secondary

spontaneous pneumothorax, traumatic pneumothorax, iatrogenic pneumothorax,

pneumomediastinum

Contributor Information and Disclosures

Author

Fahad M Al-Hameed, MD, FRCPC, AmBIM, FCCP, FRCPC,Deputy Chairman of Intensive

Care Department, Consultant in Critical Care and Pulmonary Medicine, King Khalid NationalGuard Hospital, King Abdulaziz Medical City, Saudi Arabia

Fahad M Al-Hameed, MD, FRCPC, AmBIM, FCCP, FRCPC is a member of the following

medical societies: American College of Chest Physicians, American Thoracic Society, Canadian

Medical Association, and Royal College of Physicians and Surgeons of Canada

Disclosure: Nothing to disclose.
http://www.medscape.com/medline/abstract/2376165http://www.medscape.com/medline/abstract/16537850http://www.medscape.com/medline/abstract/2063968http://www.medscape.com/medline/abstract/16281263http://www.medscape.com/medline/abstract/15609058http://www.medscape.com/medline/abstract/15741021http://www.medscape.com/medline/abstract/15741021http://www.medscape.com/medline/abstract/15609058http://www.medscape.com/medline/abstract/16281263http://www.medscape.com/medline/abstract/2063968http://www.medscape.com/medline/abstract/16537850http://www.medscape.com/medline/abstract/2376165


18/19

Coauthor(s)

Sat Sharma, MD, FRCPC,Professor and Head, Division of Pulmonary Medicine, Department of

Internal Medicine, University of Manitoba; Site Director, Respiratory Medicine, St Boniface

General Hospital

Sat Sharma, MD, FRCPC is a member of the following medical societies: American Academy of

Sleep Medicine, American College of Chest Physicians, American College of Physicians-

American Society of Internal Medicine, American Thoracic Society, Canadian Medical

Association, Royal College of Physicians and Surgeons of Canada, Royal Society of Medicine,

Society of Critical Care Medicine, and World Medical Association


Bruce Maycher, MD,Director of Pulmonary Radiology, St Boniface General Hospital; Associate

Professor, Department of Radiology, University of Manitoba

Bruce Maycher, MD is a member of the following medical societies: American Roentgen Ray

Society, Canadian Medical Association, Radiological Society of North America, and Society of

Thoracic Radiology


Medical Editor

Satinder P Singh, MD, FCCP,Professor of Radiology and Medicine, Chief of Cardiopulmonary

Radiology, Director of Cardiac CT, Director of Combined Cardiopulmonary and Abdominal

Radiology, Department of Radiology, University of Alabama at Birmingham


Pharmacy Editor

Bernard D Coombs, MB, ChB, PhD,Consulting Staff, Department of Specialist Rehabilitation

Services, Hutt Valley District Health Board, New Zealand


Managing Editor

W Richard Webb, MD,Professor, Department of Radiology, University of California at SanFrancisco


CME Editor

Robert M Krasny, MD,Resolution Imaging Medical Corporation

Robert M Krasny, MD is a member of the following medical societies: American Roentgen Ray


19/19

Society and Radiological Society of North America


Chief Editor

Eugene C Lin, MD,Consulting Radiologist, Virginia Mason Medical Center; Clinical Assistant

Professor of Radiology, University of Washington School of Medicine

Eugene C Lin, MD is a member of the following medical societies: American College of Nuclear

Medicine, American College of Radiology, Radiological Society of North America, and Society of

Nuclear Medicine


Further Reading 1994-2010 by Medscape.All Rights Reserved(http://www.medscape.com/public/copyright)

pneumothorax imaging

Documents