Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Patient is status post median sternotomy . Mild cardiomegaly is re - demonstrated , slightly accentuated due to the presence of low lung volumes . The mediastinal and hilar contours are unremarkable . Pulmonary vasculature is not engorged . Lung volumes are low with minimal patchy opacities at the lung bases , potentially atelectasis . No pleural effusion or pneumothorax is present . No acute osseous abnormalities are visualized .
    OUTPUT:
    
Low lung volumes with patchy opacities at the lung bases , likely atelectasis . Please note that infection is not excluded in the correct clinical setting .