Question 1
Which of the following is the most common cause of interstitial emphysema in neonates?
A. Pulmonary infection
B. Congenital lung malformation
C. Barotrauma from mechanical ventilation
D. Eosinophilic lung disease
Answer: C. Barotrauma from mechanical ventilation
Explanation: In neonates, interstitial emphysema is primarily caused by alveolar overdistension and rupture due to positive-pressure ventilation. This is common in preterm infants with surfactant deficiency who require respiratory support.
Reference:
Radiopaedia: Pulmonary Interstitial Emphysema. “Barotrauma from mechanical ventilation is a leading cause, especially in neonates.”
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Question 2
On chest radiography, which feature is most characteristic of pulmonary interstitial emphysema?
A. Ground-glass opacities
B. Linear and bubbly lucencies
C. Pleural effusion
D. Peribronchial cuffing
Answer: B. Linear and bubbly lucencies
Explanation: Pulmonary interstitial emphysema manifests on CXR as linear or cystic lucencies along the bronchovascular bundles or in the interstitial tissues.
Reference:
Radiographics: Radiologic Features of Pulmonary Interstitial Emphysema. “CXR demonstrates irregular linear or bubble-like lucencies in affected areas of the lung.”
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Question 3
Which imaging modality is most sensitive for detecting the air distribution in interstitial emphysema?
A. Chest X-ray
B. CT scan
C. MRI
D. Ultrasound
Answer: B. CT scan
Explanation: While chest X-ray can provide initial clues, CT is more sensitive in detecting and delineating the exact distribution and pattern of air within the interstitial spaces.
Reference:
Radiology Key: Pulmonary Interstitial Emphysema. “CT is superior to CXR for identifying small air pockets in interstitial locations.”
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Question 4
In interstitial emphysema, air most commonly tracks along which anatomical structures?
A. Alveolar walls
B. Pleural space
C. Bronchovascular bundles
D. Subcutaneous tissue
Answer: C. Bronchovascular bundles
Explanation: Interstitial air typically tracks along the bronchovascular sheaths and interlobular septa due to alveolar rupture and air leakage.
Reference:
Fleischner Glossary: Pulmonary Interstitial Emphysema. “Air tends to accumulate along the bronchovascular bundles and within the interlobular septa.”
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Question 5
Which of the following is a potential complication of untreated interstitial emphysema?
A. Pulmonary fibrosis
B. Pneumothorax
C. Pulmonary hypertension
D. Hemothorax
Answer: B. Pneumothorax
Explanation: Air in the interstitial spaces can dissect into the pleural cavity, resulting in a pneumothorax. This is a common complication if interstitial emphysema progresses untreated.
Reference:
PubMed: Complications of Pulmonary Interstitial Emphysema. “Interstitial air can lead to pneumothorax or pneumomediastinum as it tracks through interstitial tissues.”
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