Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Previously seen right mid lung and left upper lobe opacities have resolved . However , there is residual opacity of the posterior segment of the left lower lobe . A large hiatal hernia is present with adjacent left basilar atelectasis . Mediastinal silhouette is within normal limits . Midline sternotomy wires remain intact .
    OUTPUT:
    
Although there has been resolution of right mid and left upper lobe opacities , there is residual opacity of the posterior segment of the left lower lobe for which follow up chest x-ray in 4 weeks is recommended to ensure complete resolution . Large hiatal hernia .