Radiology Quiz

Spontaneous pneumomediastinum with a classical radiological sign

Ramakant Dixit, Jacob George Department of Respiratory Medicine, J. L. N. Medical College, Ajmer, Rajasthan, India E-mail: [email protected]

Address for correspondence: Dr. Ramakant Dixit, A-60, Chandravardai Nagar, Ajmer – 305 001, Rajasthan, India. E-mail: [email protected]

A 38-year-old male, with past history of pulmonary sounds on left side, and presence of palpable crepitations tuberculosis, was referred to us with worsening of over the and chest wall suggestive of surgical dyspnea for 4 days. Dyspnea was initially relieved by emphysema. The patient was in respiratory distress with bronchodilators, but for the past 2 days, there was no effect tachypnea (34/min) and hypoxia (89%) on room air. An of the medications given. He denied any history of trauma, X-ray of the chest was done urgently [Figure 1]. drug abuse, or vigorous exercise. His past history was significant for regular, adequate antituberculosis treatment Q 1: What are the radiological abnormalities? taken 10 years back. Clinical examination revealed a Q 2: What is your diagnosis? hyperresonant percussion note, reduced intensity of breath Q 3: Briefly discuss the condition with radiological signs.

Figure 1: Can you appreciate a radiological sign? Figure 2: Let’s have a closer look at the radiograph

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DOI: 10.4103/0970-2113.99126

Lung India • Vol 29 • Issue 3 • Jul - Sep 2012 295 Dixit and George: Spontaneous pneumomediastinum with a classical radiological sign

ANSWERS ligament, tubular artery sign, double bronchial wall sign, and extrapleural sign. A lateral chest X-ray is also helpful Answer 1: An incomplete film showing extensive surgical in detecting increased retrosternal air, and increases the emphysema, air in the left and paracardiac detection rate of pneumomediastinum. Vertical translucent region, collapse left , a linear hyper-translucent air streaks around the aorta and pulmonary artery also are opacity running between the lower border of heart and diagnostic of pneumomediastinum.[6,7] diaphragm [Figure 2], along with high-density nodular lesions in lung fields. “Continuous diaphragm sign” was first described by Levin.[8] It is the visualization of the continuous border Answer 2: Spontaneous on the left side, of diaphragm against the contrast of the heart shadow. pneumomediastinum with “continuous diaphragm sign” Normally obscured by the heart border, the presence of air and healed pulmonary tuberculosis. delineates the central diaphragmatic border clearly. This is best seen in frontal radiographs taken during expiration. Answer 3: The presence of air within the connective tissue This sign is also useful in trauma patients, as it is seen in planes of the is called “pneumomediastinum supine films also in contrast to the other signs.[9] or mediastinal emphysema.” The most common cause is traumatic rupture of alveoli with the dissection of Spontaneous pneumomediastinum has a benign course, air along the bronchovascular interstitium and its resolving on its own. The management of this condition is forced entry into the mediastinal connective tissue by usually supportive with reassurance, observation, treatment respiratory excursions. Less commonly, it may be caused of underlying condition, and oxygen therapy. Coexistent by tracheobronchial or , penetrating pneumothorax should be treated on its own merits. neck , or caused by gas-forming However, occasional deaths from splinting of great vessels bacterias.[1] Spontaneous pneumomediastinum is not and by the mediastinal emphysema have also been [2,10] a common clinical disorder although observed in a reported, demanding careful vigilance on this condition. variety of situations, i.e., intense exercise, scuba diving, cocaine abuse, or any cause of increased intrapleural REFERENCES pressure such as straining, positive pressure ventilation, sneezing, coughing, vomiting, etc.[2,3] There have been 1. Pierson DJ. Pneumomediastinum. In: Murray JF, Nadel JA, editor. Textbook of respiratory medicine. 2nd ed, Vol. 2. Philadelphia: WB many clinical conditions describing the occurrence Saunders Company; 1994. p. 2250-65. of pneumomediastinum, i.e., , tuberculosis, 2. Joshi N, Dixit R, Purohit SD, Gupta RC, Gupta N, Verma PC. Tracheostomy , , bronchogenic carcinoma, etc.[4,5] in life threatening primary spontaneous pneumomediastinum in a 13 year male child- a case report. Lung India 1999;17:75-8. 3. Dixit R, Joshi N. Spontaneous pneumomediastinum and pneumothorax Often presenting with chest pain, an acute onset of following vomiting. Antiseptic 2002;99:16-7. dyspnea, and swelling over neck, chest wall, and face, 4. Dixit R, Dave L. Pneumomediastinum with pneumomediastinum can be diagnosed easily on chest X-ray in silico-tuberculosis patient. Lung India 2007;24:102-4. 5. Dixit R, Joshi N, Prasad N. Pneumomediastinum, pneumothorax and films. The radiological features of pneumomediastinum subcutaneous emphysema during radiotherapy in primary cavitating include the visualization of subcutaneous emphysema, free bronchogenic carcinoma. Indian J Chest Dis Allied Sci 2002;44:61-4. mediastinal air as hyperlucent lines enhancing mediastinal 6. Beyers ZA, Melanas CF. Radiological signs of pneumomediastinum. Br viscera and outlining the lateral heart borders along J Radiol 1987;60:877-9. 7. Bejvan SM, Godwin JD, Pneumomediastinum: Old signs and new signs. with superior mediastinal widening. Other signs include Am J Radiol 1996;166:1041-8. continuous diaphragm sign, continuous left hemidiaphragm 8. Levin B. The continuous diaphragm sign: A newly recognized sign of sign, ring-aroundpulmonary-artery sign (air surrounding pneumomediastinum. Clin Radiol 1973;24:337-8. the extrapericardial segment of the right main pulmonary 9. Macpherson P, Davidson JS. Continous diaphragm sign of pneumo- mediastinum. Br Med J 1974;2(5910)119-20. artery and appearing as a lucent ring around the right 10. Rydell JR. Emergency cervical mediastinotomy for massive mediastinal pulmonary artery), thymic/spinnaker sail sign (outlining emphysema. Arch Surg 1955;70:647-53. of the thymus due to large pneumomediastinum elevating the thymic lobes), V sign (confluence of innominate veins outlined in a frontal view), Naclerio’s V sign (air outlining How to cite this article: Dixit R, George J. Spontaneous the lateral border of the descending aorta and extending pneumomediastinum with a classical radiological sign. Lung India 2012;29:295-6. laterally between the parietal pleura and medial left hemidiaphragm), pneumoprecardium, air in the pulmonary Source of Support: Nil, Conflict of Interest: None declared.

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