Summarize the radiology report findings into an impression within 3 sentences.
    INPUT: Since previous examination , increased interstitial abnormality extends from the infrahilar areas bilaterally into the mid and lower lungs and to a lesser degree , in the upper lungs , without focal consolidation , pleural effusion , or pneumothorax . Heart and mediastinal contours are unremarkable .
    OUTPUT:
    
Increased interstitial abnormality is suspicious for pneumocystis infection as on the previous examination ; however , other atypical infections and pulmonary edema can have a similar appearance in this patient without obvious cardiac history .