Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: There has been an interval decrease in the degree of mild interstitial pulmonary edema , with the remaining diffuse interstitial abnormality thought to be secondary to changes related to known Langerhans cell histiocytosis as opposed to persistent pulmonary edema . At the right medial lung base , there is a less conspicuous heterogeneous opacity which could reflect an infectious process . A similar opacity in the left mid to lower lung is also less apparent on today 's today . Left retrocardiac atelectasis is increased . Small - to - moderate bilateral pleural effusions are not significantly changed . There is no pneumothorax . Mild - to - moderate cardiomegaly is not significantly changed .
    OUTPUT:
    
1 . Interval near complete resolution of pulmonary edema with residual chronic interstitial abnormality thought to be secondary to known Langerhans cell lymphohistiocytosis . 2 . Decreased right medial lung base and left mid - to - lower lung heterogeneous opacities , possibly infection in the appropriate clinical setting . 3 . Increased left retrocardiac atelectasis . 4 . Unchanged small - to - moderate bilateral pleural effusions .