Emerg Radiol (2013) 20:563–564 DOI 10.1007/s10140-013-1170-4
PICTORIAL ESSAY
Core curriculum illustration: pneumothorax Gustav Blomquist & David Nickels & Gary Merhar & Fred Mann
Received: 9 October 2013 / Accepted: 10 October 2013 / Published online: 8 November 2013 # Am Soc Emergency Radiol 2013
Abstract This is the fourth installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at http:// www.aseronline.org/curriculum/toc.htm.
History An 18-year-old man presented with pleuritic left-sided chest pain. A chest PA and lateral radiographs were requested.
Findings The PA radiograph (Fig. 1) demonstrates an abnormally lucent left hemithorax. A thin white outer line of the lung/visceral pleura pneumothorax interface is seen without more peripheral vasculature or distal lung markings [1]. Blunting of the costophrenic angle is consistent with a tiny pleural effusion. The PA radiograph (Fig. 2) immediately follows anterior chest tube placement and demonstrates some residual apical pneumothorax. The visceral pleural curvilinear line parallels the chest wall [2]. The patient recovered fully and G. Blomquist (*) : D. Nickels : G. Merhar Department of Radiology, University of Kentucky, 800 Rose Street, Room HX 318X, Lexington, KY 40356-0293, USA e-mail: [email protected] F. Mann 1226 Federal Ave. East, Seattle, WA 98102, USA
the thoracostomy tube was removed 2 days later without complications.
Discussion A pneumothorax is the abnormal presence of air in the pleural space. Air enters into the pleural space either from the bronchopulmonary system or through the chest wall, which is generally due to trauma. In young patients, a pneumothorax is frequently the result of bleb rupture [2]. Patients warrant closer observation when an underlying cause for a pneumothorax is present, such as emphysema, pulmonary fibrosis of any cause, cystic fibrosis, pneumonia, and/or cystic interstitial lung diseases. Diagnosis of a pneumothorax on radiographs is made by identifying a visceral pleural line paralleling the chest wall without more peripheral lung opacities. On upright radiographs, the nondependent air is seen apically when not loculated. On lateral radiographs, the visceral pleural line can be in the retrosternal position or overlying the spine depending on the patient position [3]. Expiratory upright radiographs slightly increase diagnostic sensitivity. A lateral decubitus or full inspiratory radiograph may be the only studies where the pneumothorax is visible. Recumbent radiographs are substantially less sensitive to detection of pneumothoraces (ie, approximately 30 % of pneumothoraces not shown) [4]. Critically ill patients are frequently imaged in the supine position, so the radiologist should remember that the least dependent part of the chest is the anterior medial and inferior portion of the lung. Instead of a pleural line apicolaterally, the air tracks to the cardiophrenic and costophrenic angles, which may be enlarged [5]. A “deep sulcus sign” is an abnormally deep and hyperlucent lateral costophrenic angle on a supine radiograph. The mediastinal borders may appear too sharp, and the affected side of the lung
564
Fig. 1 PA radiograph of an abnormally lucent left lung. Blunting of the costophrenic angle is consistent with a tiny pleural effusion
may be hyperlucent. A “double-diaphragm sign” is the result of pleural air outlining the dome and anterior medial diaphragm in the supine position [6]. In giant bullous emphysema, which has also been called vanishing lung syndrome, the diagnosis cannot always be made by radiographs; in vanishing lung syndrome by CT, a pneumothorax may have a “double-wall sign,” which is when air outlines both sides of the bulla wall parallel to the chest wall [7]. Several other pitfalls exist in the diagnosis of a pneumothorax. Skin folds, which are redundant skin between the patient and imaging plate, frequently mimic the curvilinear visceral pleural line, but the skinfold has a black line as
Emerg Radiol (2013) 20:563–564
opposed to the white visceral pleural mach line. In addition, the skinfold line may extend beyond the edge where a pneumothorax can occur and have peripheral lung markings. Bullae may simulate the hyperlucency and, sometimes, the visceral pleural line so much so as to require CT for confirmation [7]. Clothing or bedsheets may project as straight lines that extend beyond the patient and do not parallel the chest wall. Companion shadows adjacent to the inferior border of the ribs may project as a confusing line. The medial border of the scapula should be traced and excluded. Finally, lung surgery changes can be misinterpreted as a pneumothorax. Complications of pneumothoraces include mediastinal shift that results in hemodynamic compromise, which is called a tension pneumothorax. In this case, the size of the pneumothorax and position warrant the consideration of a “fallen lung” sign. If the pneumothorax is rapidly progressive and/or refractory to the chest tube, a partial or complete bronchial rupture and bronchopleural fistula should be considered. Bronchopleural fistulas have been reported in less than 1 % of patients and should be considered in patients with underlying lung disease or trauma [8]. Blind chest drain placement can lead to an iatrogenic air leak from direct trauma to the pleura or into the posterior pleural space away from the nondependent pneumothorax; therefore, a posttreatment radiograph should be obtained to detect complications and confirm drain position. The drain side holes should be in the pleural space. In summary, a radiologist must remain vigilant for an unexpected pneumothorax by maintaining a search pattern that accounts for patient positioning, radiograph technique, and clinical history. Conflict of interest The authors declare that they have no conflict of interest.
References
Fig. 2 Immediate postprocedure chest PA radiograph demonstrates some residual apical pneumothorax. The visceral pleural curvilinear line parallels the chest wall
1. Chasen MH (2001) Practical applications of Mach band theory in thoracic analysis. Radiology 219:596–610 2. Brant WE, Helms C (2012) Fundamentals of diagnostic radiology, 3rd edn. Lippincott Williams & Wilkins, Philadelphia, pp 383–385 3. Glazer H (1989) Pneumothorax: appearances on lateral chest radiographs. Radiology 173:707–11 4. Tocino IM (1985) Pneumothorax in the supine patient: radiographic anatomy. RadioGraphics 5:557–586 5. O'Connor AR, Morgan WE (2005) Radiological review of pneumothorax. Br Med J 330(7506):1493–1497 6. Kong A (2003) The deep sulcus sign. Radiology 228:415–416 7. Waitches GM (2000) Usefulness of the double-wall sign in detecting pneumothorax in patients with giant bullous emphysema. Am J Roentgenol 174(6):1765–1768 8. Savaş R, Alper H (2008) Fallen lung sign: radiographic findings. Diagn Interv Radiol 14:120–121
PICTORIAL ESSAY
Core curriculum illustration: pneumothorax Gustav Blomquist & David Nickels & Gary Merhar & Fred Mann
Received: 9 October 2013 / Accepted: 10 October 2013 / Published online: 8 November 2013 # Am Soc Emergency Radiol 2013
Abstract This is the fourth installment of a series that will highlight one case per publication issue from the bank of cases available online as part of the American Society of Emergency Radiology (ASER) educational resources. Our goal is to generate more interest in and use of our online materials. To view more cases online, please visit the ASER Core Curriculum and Recommendations for Study online at http:// www.aseronline.org/curriculum/toc.htm.
History An 18-year-old man presented with pleuritic left-sided chest pain. A chest PA and lateral radiographs were requested.
Findings The PA radiograph (Fig. 1) demonstrates an abnormally lucent left hemithorax. A thin white outer line of the lung/visceral pleura pneumothorax interface is seen without more peripheral vasculature or distal lung markings [1]. Blunting of the costophrenic angle is consistent with a tiny pleural effusion. The PA radiograph (Fig. 2) immediately follows anterior chest tube placement and demonstrates some residual apical pneumothorax. The visceral pleural curvilinear line parallels the chest wall [2]. The patient recovered fully and G. Blomquist (*) : D. Nickels : G. Merhar Department of Radiology, University of Kentucky, 800 Rose Street, Room HX 318X, Lexington, KY 40356-0293, USA e-mail: [email protected] F. Mann 1226 Federal Ave. East, Seattle, WA 98102, USA
the thoracostomy tube was removed 2 days later without complications.
Discussion A pneumothorax is the abnormal presence of air in the pleural space. Air enters into the pleural space either from the bronchopulmonary system or through the chest wall, which is generally due to trauma. In young patients, a pneumothorax is frequently the result of bleb rupture [2]. Patients warrant closer observation when an underlying cause for a pneumothorax is present, such as emphysema, pulmonary fibrosis of any cause, cystic fibrosis, pneumonia, and/or cystic interstitial lung diseases. Diagnosis of a pneumothorax on radiographs is made by identifying a visceral pleural line paralleling the chest wall without more peripheral lung opacities. On upright radiographs, the nondependent air is seen apically when not loculated. On lateral radiographs, the visceral pleural line can be in the retrosternal position or overlying the spine depending on the patient position [3]. Expiratory upright radiographs slightly increase diagnostic sensitivity. A lateral decubitus or full inspiratory radiograph may be the only studies where the pneumothorax is visible. Recumbent radiographs are substantially less sensitive to detection of pneumothoraces (ie, approximately 30 % of pneumothoraces not shown) [4]. Critically ill patients are frequently imaged in the supine position, so the radiologist should remember that the least dependent part of the chest is the anterior medial and inferior portion of the lung. Instead of a pleural line apicolaterally, the air tracks to the cardiophrenic and costophrenic angles, which may be enlarged [5]. A “deep sulcus sign” is an abnormally deep and hyperlucent lateral costophrenic angle on a supine radiograph. The mediastinal borders may appear too sharp, and the affected side of the lung
564
Fig. 1 PA radiograph of an abnormally lucent left lung. Blunting of the costophrenic angle is consistent with a tiny pleural effusion
may be hyperlucent. A “double-diaphragm sign” is the result of pleural air outlining the dome and anterior medial diaphragm in the supine position [6]. In giant bullous emphysema, which has also been called vanishing lung syndrome, the diagnosis cannot always be made by radiographs; in vanishing lung syndrome by CT, a pneumothorax may have a “double-wall sign,” which is when air outlines both sides of the bulla wall parallel to the chest wall [7]. Several other pitfalls exist in the diagnosis of a pneumothorax. Skin folds, which are redundant skin between the patient and imaging plate, frequently mimic the curvilinear visceral pleural line, but the skinfold has a black line as
Emerg Radiol (2013) 20:563–564
opposed to the white visceral pleural mach line. In addition, the skinfold line may extend beyond the edge where a pneumothorax can occur and have peripheral lung markings. Bullae may simulate the hyperlucency and, sometimes, the visceral pleural line so much so as to require CT for confirmation [7]. Clothing or bedsheets may project as straight lines that extend beyond the patient and do not parallel the chest wall. Companion shadows adjacent to the inferior border of the ribs may project as a confusing line. The medial border of the scapula should be traced and excluded. Finally, lung surgery changes can be misinterpreted as a pneumothorax. Complications of pneumothoraces include mediastinal shift that results in hemodynamic compromise, which is called a tension pneumothorax. In this case, the size of the pneumothorax and position warrant the consideration of a “fallen lung” sign. If the pneumothorax is rapidly progressive and/or refractory to the chest tube, a partial or complete bronchial rupture and bronchopleural fistula should be considered. Bronchopleural fistulas have been reported in less than 1 % of patients and should be considered in patients with underlying lung disease or trauma [8]. Blind chest drain placement can lead to an iatrogenic air leak from direct trauma to the pleura or into the posterior pleural space away from the nondependent pneumothorax; therefore, a posttreatment radiograph should be obtained to detect complications and confirm drain position. The drain side holes should be in the pleural space. In summary, a radiologist must remain vigilant for an unexpected pneumothorax by maintaining a search pattern that accounts for patient positioning, radiograph technique, and clinical history. Conflict of interest The authors declare that they have no conflict of interest.
References
Fig. 2 Immediate postprocedure chest PA radiograph demonstrates some residual apical pneumothorax. The visceral pleural curvilinear line parallels the chest wall
1. Chasen MH (2001) Practical applications of Mach band theory in thoracic analysis. Radiology 219:596–610 2. Brant WE, Helms C (2012) Fundamentals of diagnostic radiology, 3rd edn. Lippincott Williams & Wilkins, Philadelphia, pp 383–385 3. Glazer H (1989) Pneumothorax: appearances on lateral chest radiographs. Radiology 173:707–11 4. Tocino IM (1985) Pneumothorax in the supine patient: radiographic anatomy. RadioGraphics 5:557–586 5. O'Connor AR, Morgan WE (2005) Radiological review of pneumothorax. Br Med J 330(7506):1493–1497 6. Kong A (2003) The deep sulcus sign. Radiology 228:415–416 7. Waitches GM (2000) Usefulness of the double-wall sign in detecting pneumothorax in patients with giant bullous emphysema. Am J Roentgenol 174(6):1765–1768 8. Savaş R, Alper H (2008) Fallen lung sign: radiographic findings. Diagn Interv Radiol 14:120–121
