Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: The heart is borderline in size . The aorta is mildly tortuous . There is a patchy retrocardiac opacity obscuring the left hemidiaphragm , visible posteriorly on the lateral view . Aside from vague asymmetric hazy opacity that may refer to the lingula , otherwise , the lungs appear clear . There is no definite pleural effusion or pneumothorax . Bony structures are unremarkable .
    OUTPUT:
    
Patchy opacities in the left lung , within the left lower lobe and possibly lingula . This appearance is fairly typical for atelectasis but if there is clinical concern regarding possible development of pneumonia , short - term followup radiographs may be helpful to re-assess .