FINDINGS:
The lungs are normally expanded. There is left retrocardiac airspace opacity
 projecting over the spine on the lateral radiograph.  Heart size is normal.
 The mediastinal and hilar contours are normal. There is no pleural effusion or
 pneumothorax. There is S shaped curvature of the thoracolumbar spine.

IMPRESSION:
Left retrocardiac opacity projecting over the spine is worrisome for
 pneumonia.  Recommend followup chest radiographs in 4 weeks after completion
 of antibiotic therapy to assess for resolution.