Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: PA and lateral chest views were obtained with patient in upright position . Comparison is made with the next preceding similar study of ___ . The heart size is normal . No configurational abnormalities are identified . Thoracic aorta unremarkable . The pulmonary vasculature is not congested . As shown on previous examination , there is evidence of bilateral , mostly basal , emphysema with rarefied vasculature , flattened diaphragms , and increased translucencies rather typical for bilateral basal emphysema . Lateral pleural sinuses as well as the posterior sinuses are free from any remaining pleural effusion . No new parenchymal infiltrates are identified , and no residual pneumothorax is seen in the right hemithorax apical area . In comparison with the next preceding examination , the small right - sided pleural effusion has now disappeared and the same holds for some parenchymal infiltrates in the right upper lobe area which now have cleared . Skeletal structures of the thorax are grossly within normal limits with the exception of some minor degenerative changes in the mid portion of the thoracic spine .
    OUTPUT:
    
Normalization of chest findings in patient with previous right - sided spontaneous pneumothorax . Rather marked bilateral basal emphysematous changes remain .