Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: 2 views were obtained of the chest . Moderate - sized left pleural effusion may be loculated and is located anteriorly with accompanying opacification of the left lung base which may reflect compressive atelectasis though a component of infectious pathology can not be excluded . Left apical pleural thickening and surrounding interstitial abnormality is of uncertain acuity given absence of prior studies though in the setting of prior breast cancer , this could reflect post radiation changes . Mild right basilar opacity is also of uncertain significance and could reflect atelectasis or infectious process . The heart and mediastinum are unremarkable though slightly shifted to the right . No pneumothorax .
    OUTPUT:
    
Possibly loculated left pleural effusion with bibasilar opacities which could reflect atelectasis or infection . Left apical pleural and parenchymal changes are of uncertain acuity and may relate to prior radiation therapy .