Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Apparent left retrocardiac patchy opacity seen on the frontal view , not substantiated on the lateral view , most likely represents atelectasis . No definite focal consolidation is seen . No pleural effusion or pneumothorax is seen . The cardiac and mediastinal silhouettes are unremarkable .
    OUTPUT:
    
No acute cardiopulmonary process .