MyPACS.net: Radiology Teaching Files > Case 10219960

Never visited CONTINUOUS DIAPHRAM SIGN IN PNEUMOMEDIASTIMUN
Contributed by: Radiology Residency Program Faculty & Staff, Northeastern Ohio Universities College of Medicine-Canton Affiliated Hospitals, Ohio, USA.
Patient: 67 year old male
History: 68 y M was on ventilator. He developed acute respiratory distress and hypoxia.
Images:[small]larger

Fig. 1: Bilateral PTX. Peumomediastinum is seen inferior to the diaphramatic surface of the heart.

Fig. 2: Pneumomediastinum is seen as 'continuous diaphram sign'.
Findings: As image legends.
Discussion: Pneumomediastinum

    • Air in the mediastinal space
      • Most common in infants
      • Rare in adults except in ICU patient!!
        • Result of trauma
          • Rupture of esophagus
          • Rupture of airways
    • Air in mediastinum originates from
      • Lung
        • Most common mechanism in neonates and adults
          • Begins with rupture of alveolus
            • Usually from increased intraparenchymal pressure
          • Air dissects back along perivascular sheaths to hilum and mediastinum
        • Air from ruptured bleb can also extend peripherally into pleural space
          • Pneumothorax
        • Most instances can be related to sudden rise in intrapulmonary pressure
          • Asthma
          • Vomiting
          • Valsalva maneuver
          • Artificial ventilation
          • Closed chest trauma
          • Sudden drop in atmospheric pressure
      • Mediastinal airways

        • Rupture of trachea or mainstem bronchus

          • Usually produced by accidental trauma

      • Esophagus

  • §         Rupture of the esophagus – Boerhaave’s Syndrome             

    §         Can occur with

          • Vomiting

          • Labor
          • Severe asthmatic attacks
          • Strenuous exercise (each of these can produce pneumomediastinum without rupturing the esophagus)
          • Site of perforation
            • Left, posterolateral wall, distal 8 cm

     

  • Imaging findings

     

    • Linear density parallel to heart border
      • Separated from heart by air
    • Also ring lucency around aorta or pulmonary artery
      • “Ring around the artery” sign
    • Dissection of air into neck is much less common in infants than adults
    • Dissection into chest wall much less common in neonates than older
    • Air can outline the central portion of the diaphragm
    • “Continuous diaphragm sign”

    • Clinical Findings
      • Abrupt onset of retrosternal pain
        • Usually preceded by episode of vomiting
        • Pain is worse on inspiration
        • Dyspnea could be severe
      • Hamman’s sign – crunching sound heard over the apex of the heart with cardiac cycle
References: http://learningradiology.com/notes/chestnotes/Pneumomediastinumpage.htm
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Additional Details:

Case Number: 10219960Last Updated: 2007-08-20
Anatomy: Chest   Pathology: Iatrogenic
Modality: Conventional RadiographAccess Level: Readable by all users

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