Newborn with respiratory distress

CXR and CT of pulmonary agenesis
CXR AP (above) shows complete opacification of the left hemithorax with mediastinal shift to the left. Axial CT without contrast of the chest (below) show hyperexpansion of the right lung with herniation across the midline, mediastinal shift to the left, and non-visualization of the left mainstem bronchus.

The diagnosis was left pulmonary agenesis.